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Nefazodone

Pronunciation

Pronunciation

(nef AY zoe done)

Index Terms

  • Nefazodone Hydrochloride
  • Serzone

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral, as hydrochloride:

Generic: 50 mg, 100 mg, 150 mg, 200 mg, 250 mg

Pharmacologic Category

  • Antidepressant, Serotonin Reuptake Inhibitor/Antagonist

Pharmacology

Inhibits neuronal reuptake of serotonin and norepinephrine; also blocks 5-HT2 and alpha1 receptors; has no significant affinity for alpha2, beta-adrenergic, 5-HT1A, cholinergic, dopaminergic, or benzodiazepine receptors

Absorption

Rapid; well absorbed; food delays absorption by ~20%

Distribution

Vd: 0.22 to 0.87 L/kg

Metabolism

Hepatic by n-dealkylation and aliphatic and aromatic hydroxylation to at least three metabolites: Triazoledione, hydroxynefazodone (active), and m-chlorophenylpiperazine (mCPP; active)

Excretion

Primarily urine (~55%; as metabolites); feces (~20 to 30%)

Time to Peak

Note: Prolonged in presence of food

Children and Adolescents: 0.5 to 1 hour

Adults: Serum: 1 hour

Half-Life Elimination

Note: Active metabolites persist longer in all populations.

Children: 4.1 hours

Adolescents: 3.9 hours

Adults: Parent drug: 2 to 4 hours; active metabolites: 1.4 to 8 hours

Protein Binding

>99%

Special Populations: Elderly

Cmax and AUC for nefazodone and hydroxynefazodone were twice as high in patients older than 65 years after single doses and 10% to 20% higher after multiple doses.

Special Populations: Gender

Nefazodone has a higher Cmax and AUC in women after single doses, but no difference after multiple doses.

Use: Labeled Indications

Depression: Treatment of depression

Contraindications

Hypersensitivity to nefazodone, related compounds (phenylpiperazines), or any component of the formulation; liver injury due to previous nefazodone treatment, active liver disease, or elevated serum transaminases; concurrent use or use of MAO inhibitors within previous 14 days; concurrent use with carbamazepine, cisapride, or pimozide; concurrent therapy with triazolam is generally contraindicated (dosage must be reduced by 75% for triazolam; such reductions may not be possible with available dosage forms).

Dosing: Adult

Depression: Oral: Initial: 100 mg twice daily; alternatively depression treatment guidelines suggest starting doses of 50 to 100 mg daily (APA, 2010; Bauer 2013). Based on response and tolerability, gradually increase dose in increments of 100 to 200 mg daily (in 2 divided doses) and intervals of no less than 1 week to a usual dose of 150 to 600 mg daily in 2 divided doses

Discontinuation of therapy: Upon discontinuation of antidepressant therapy, gradually taper the dose to minimize the incidence of withdrawal symptoms and allow for the detection of re-emerging symptoms. Evidence supporting ideal taper rates is limited. APA and NICE guidelines suggest tapering therapy over at least several weeks with consideration to the half-life of the antidepressant; antidepressants with a shorter half-life may need to be tapered more conservatively. In addition for long-term treated patients, WFSBP guidelines recommend tapering over 4 to 6 months. If intolerable withdrawal symptoms occur following a dose reduction, consider resuming the previously prescribed dose and/or decrease dose at a more gradual rate (APA, 2010; Bauer, 2002; Haddad, 2001; NCCMH, 2010; Schatzberg, 2006; Shelton, 2001; Warner, 2006).

MAO inhibitor recommendations:

Switching to or from an MAO inhibitor intended to treat psychiatric disorders:

Allow 14 days to elapse between discontinuing an MAO inhibitor intended to treat psychiatric disorders and initiation of nefazodone.

Allow 14 days to elapse between discontinuing nefazodone and initiation of an MAO inhibitor intended to treat psychiatric disorders.

Use with other MAO inhibitors (such as linezolid or IV methylene blue):

Do not initiate nefazodone in patients receiving linezolid or IV methylene blue; consider other interventions for psychiatric condition.

If urgent treatment with linezolid or IV methylene blue is required in a patient already receiving nefazodone and potential benefits outweigh potential risks, discontinue nefazodone promptly and administer linezolid or IV methylene blue. Monitor for serotonin syndrome for 2 weeks or until 24 hours after the last dose of linezolid or IV methylene blue, whichever comes first. May resume nefazodone 24 hours after the last dose of linezolid or IV methylene blue.

Dosing: Geriatric

Depression: Oral: Initial: 50 mg twice daily; gradually increase dose based on response and tolerability

Discontinuation of therapy: Refer to adult dosing.

MAO inhibitor recommendations: Refer to adult dosing.

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer’s labeling; however, adjustment unlikely since renal impairment does not alter steady state nefazodone plasma concentrations.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling; however, use with caution since the AUC of nefazodone and its metabolites are ~25% greater in patients with cirrhosis.

Administration

Administer with or without food. Dosing after meals may decrease lightheadedness and postural hypotension, but may also decrease absorption and therefore effectiveness.

Storage

Store at 20°C to 25°C (68°F to 77°F).

Drug Interactions

Abiraterone Acetate: May increase the serum concentration of CYP2D6 Substrates. Management: Avoid concurrent use of abiraterone with CYP2D6 substrates that have a narrow therapeutic index whenever possible. When concurrent use is not avoidable, monitor patients closely for signs/symptoms of toxicity. Consider therapy modification

Ado-Trastuzumab Emtansine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Ado-Trastuzumab Emtansine. Specifically, strong CYP3A4 inhibitors may increase concentrations of the cytotoxic DM1 component. Avoid combination

Ajmaline: May increase the serum concentration of CYP2D6 Substrates. Monitor therapy

Alfuzosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alfuzosin. Avoid combination

Alitretinoin (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alitretinoin (Systemic). Management: Consider reducing the alitretinoin dose to 10 mg when used together with strong CYP3A4 inhibitors. Monitor for increased alitretinoin effects/toxicities if combined with a strong CYP3A4 inhibitor. Consider therapy modification

Almotriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Almotriptan. Management: Limit initial almotriptan adult dose to 6.25 mg and maximum adult dose to 12.5 mg/24-hrs when used with a strong CYP3A4 inhibitor. Avoid concurrent use in patients with impaired hepatic or renal function. Consider therapy modification

Alosetron: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Alosetron. Monitor therapy

AmLODIPine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of AmLODIPine. Monitor therapy

Amodiaquine: CYP2C8 Inhibitors may increase the serum concentration of Amodiaquine. Avoid combination

Analgesics (Opioid): May enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Monitor therapy

Antiemetics (5HT3 Antagonists): May enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Monitor therapy

Antipsychotic Agents: Serotonin Modulators may enhance the adverse/toxic effect of Antipsychotic Agents. Specifically, serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotic Agents may enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Monitor therapy

Antipsychotic Agents (Phenothiazines): May enhance the adverse/toxic effect of Antidepressants (Serotonin Reuptake Inhibitor/Antagonist). Specifically, this may be manifest as symptoms consistent with serotonin syndrome or neuroleptic malignant syndrome. Antidepressants (Serotonin Reuptake Inhibitor/Antagonist) may enhance the hypotensive effect of Antipsychotic Agents (Phenothiazines). Monitor therapy

Apixaban: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Apixaban. Monitor therapy

Aprepitant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Aprepitant. Avoid combination

ARIPiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of ARIPiprazole. Management: See full interaction monograph for details. Consider therapy modification

ARIPiprazole Lauroxil: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of ARIPiprazole Lauroxil. Management: Please refer to the full interaction monograph for details concerning the recommended dose adjustments. Consider therapy modification

Astemizole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Astemizole. Avoid combination

Asunaprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Asunaprevir. Avoid combination

Avanafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Avanafil. Avoid combination

Axitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Axitinib. Management: Avoid concurrent use of axitinib with any strong CYP3A inhibitor whenever possible. If a strong CYP3A inhibitor must be used with axitinib, a 50% axitinib dose reduction is recommended. Avoid combination

Barnidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Barnidipine. Avoid combination

Bedaquiline: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bedaquiline. Management: Limit the duration of concomitant administration of bedaquiline with CYP3A4 inhibitors to no more than 14 days, unless the benefit of continued administration is judged to outweigh the possible risks. Monitor for toxic effects of bedaquiline. Consider therapy modification

Blonanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Blonanserin. Avoid combination

Bortezomib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bortezomib. Monitor therapy

Bosentan: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Bosentan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bosentan. Management: Concomitant use of both a CYP2C9 inhibitor and a CYP3A inhibitor or a single agent that inhibits both enzymes with bosentan is likely to cause a large increase in serum concentrations of bosentan and is not recommended. See monograph for details. Monitor therapy

Bosutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bosutinib. Avoid combination

Brentuximab Vedotin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be increased. Monitor therapy

Brexpiprazole: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brexpiprazole. Management: Reduce brexpiprazole dose to 50% of usual with a strong CYP3A4 inhibitor; reduce to 25% of usual if used with both a moderate CYP3A4 inhibitor and a CYP2D6 inhibitor, or if a strong CYP3A4 inhibitor is used in a CYP2D6 poor metabolizer. Consider therapy modification

Brinzolamide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Brinzolamide. Monitor therapy

Bromocriptine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Bromocriptine. Avoid combination

Budesonide (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Nasal). Monitor therapy

Budesonide (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Oral Inhalation). Monitor therapy

Budesonide (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Systemic). Avoid combination

Budesonide (Topical): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Budesonide (Topical). Management: Per US prescribing information, avoid this combination. Canadian product labeling does not recommend strict avoidance. If combined, monitor for excessive glucocorticoid effects as budesonide exposure may be increased. Consider therapy modification

Buprenorphine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Buprenorphine. Monitor therapy

BusPIRone: May enhance the serotonergic effect of Antidepressants (Serotonin Reuptake Inhibitor/Antagonist). Management: The combination of a serotonin reuptake inhibitor,antagonist and buspirone should be undertaken with great caution. When combined treatment is clinically indicated, monitor closely for signs of serotonin toxicity/serotonin syndrome. Consider therapy modification

Cabazitaxel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabazitaxel. Management: Concurrent use of cabazitaxel with strong inhibitors of CYP3A4 should be avoided when possible. If such a combination must be used, consider a 25% reduction in the cabazitaxel dose. Consider therapy modification

Cabozantinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cabozantinib. Management: Avoid use of a strong CYP3A4 inhibitor with cabozantinib if possible. If combined, cabozantinib dose adjustments are recommended and vary based on the cabozantinib product used and the indication for use. See monograph for details. Consider therapy modification

Calcifediol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Calcifediol. Monitor therapy

Cannabis: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be increased. Monitor therapy

CarBAMazepine: Nefazodone may increase the serum concentration of CarBAMazepine. Also, concentrations of the active CarBAMazepine epoxide metabolite may be reduced. CarBAMazepine may decrease the serum concentration of Nefazodone. Concentrations of active Nefazodone metabolites may also be reduced. Avoid combination

Cariprazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cariprazine. Management: Cariprazine dose reductions of 50% are required; specific recommended management varies slightly for those stable on cariprazine versus those just starting cariprazine. See prescribing information or full interaction monograph for details. Consider therapy modification

Ceritinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ceritinib. Management: If such combinations cannot be avoided, the ceritinib dose should be reduced by approximately one-third (to the nearest 150 mg). Resume the prior ceritinib dose after cessation of the strong CYP3A4 inhibitor. Avoid combination

Cilostazol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cilostazol. Management: Consider reducing the cilostazol dose to 50 mg twice daily in adult patients who are also receiving strong inhibitors of CYP3A4. Consider therapy modification

Cisapride: Nefazodone may increase the serum concentration of Cisapride. Avoid combination

CloZAPine: Nefazodone may decrease the metabolism of CloZAPine. Monitor therapy

Cobimetinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Cobimetinib. Avoid combination

Colchicine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Colchicine. Management: Colchicine is contraindicated in patients with impaired renal or hepatic function who are also receiving a strong CYP3A4 inhibitor. In those with normal renal and hepatic function, reduce colchicine dose as directed. Consider therapy modification

Conivaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Conivaptan. Avoid combination

Conivaptan: May increase the serum concentration of CYP3A4 Substrates. Avoid combination

Corticosteroids (Orally Inhaled): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Corticosteroids (Orally Inhaled). Management: Orally inhaled fluticasone propionate with a strong CYP3A4 inhibitor is not recommended. Exceptions: Beclomethasone (Oral Inhalation); Triamcinolone (Systemic). Monitor therapy

Corticosteroids (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Corticosteroids (Systemic). Exceptions: MethylPREDNISolone; PrednisoLONE (Systemic); PredniSONE. Monitor therapy

Crizotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Crizotinib. Avoid combination

CYP2D6 Inhibitors (Moderate): May decrease the metabolism of CYP2D6 Substrates. Monitor therapy

CYP2D6 Inhibitors (Strong): May decrease the metabolism of CYP2D6 Substrates. Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

CYP3A4 Inhibitors (Moderate): May decrease the metabolism of CYP3A4 Substrates. Monitor therapy

CYP3A4 Inhibitors (Strong): May decrease the metabolism of CYP3A4 Substrates. Consider therapy modification

CYP3A4 Substrates: CYP3A4 Inhibitors (Strong) may decrease the metabolism of CYP3A4 Substrates. Exceptions: Alitretinoin (Systemic); AmLODIPine; Buprenorphine; Gefitinib; HYDROcodone; Praziquantel; Telithromycin; Vinorelbine. Consider therapy modification

Dabrafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dabrafenib. Avoid combination

Daclatasvir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Daclatasvir. Management: Decrease the daclatasvir dose to 30 mg once daily if combined with a strong CYP3A4 inhibitor. No dose adjustment is needed when daclatasvir is used with darunavir/cobicistat. Consider therapy modification

Dapoxetine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dapoxetine. Avoid combination

Dapoxetine: May enhance the adverse/toxic effect of Serotonin Modulators. Avoid combination

Dasatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dasatinib. Management: Use of this combination should be avoided; consider reducing dasatinib dose if a strong CYP3A4 inhibitor must be used. If using dasatinib 100 mg/day, consider reduction to 20 mg/day; if using dasatinib 140 mg/day, consider reduction to 40 mg/day. Consider therapy modification

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Dienogest: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dienogest. Monitor therapy

Digoxin: Nefazodone may increase the serum concentration of Digoxin. Monitor therapy

Dofetilide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dofetilide. Monitor therapy

Domperidone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Domperidone. Avoid combination

Doxercalciferol: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Doxercalciferol. Monitor therapy

DOXOrubicin (Conventional): CYP3A4 Inhibitors (Strong) may increase the serum concentration of DOXOrubicin (Conventional). Management: Seek alternatives to strong CYP3A4 inhibitors in patients treated with doxorubicin whenever possible. One U.S. manufacturer (Pfizer Inc.) recommends that these combinations be avoided. Consider therapy modification

Dronabinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dronabinol. Monitor therapy

Dronedarone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dronedarone. Avoid combination

Drospirenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Drospirenone. Monitor therapy

Dutasteride: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Dutasteride. Monitor therapy

Eletriptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eletriptan. Avoid combination

Eliglustat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eliglustat. Management: Use should be avoided under some circumstances. See full drug interaction monograph for details. Consider therapy modification

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates. Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification

Eplerenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eplerenone. Avoid combination

Erlotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Erlotinib. Management: Avoid use of this combination when possible. When the combination must be used, monitor the patient closely for the development of severe adverse reactions, and if such severe reactions occur, reduce the erlotinib dose (in 50 mg decrements). Consider therapy modification

Estazolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Estazolam. Monitor therapy

Eszopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Eszopiclone. Management: Limit the eszopiclone dose to 2 mg daily when combined with strong CYP3A4 inhibitors and monitor for increased eszopiclone effects and toxicities (eg, somnolence, drowsiness, CNS depression). Consider therapy modification

Etizolam: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Etizolam. Management: Consider use of lower etizolam doses when using this combination; specific recommendations concerning dose adjustment are not available. Monitor clinical response to the combination closely. Consider therapy modification

Everolimus: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Everolimus. Avoid combination

FentaNYL: CYP3A4 Inhibitors (Strong) may increase the serum concentration of FentaNYL. Management: Monitor patients closely for several days following initiation of this combination, and adjust fentanyl dose as necessary. Consider therapy modification

Fesoterodine: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Fesoterodine. Management: Avoid fesoterodine doses greater than 4 mg daily in adult patients who are also receiving strong CYP3A4 inhibitors. Consider therapy modification

Flibanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Flibanserin. Avoid combination

Fluticasone (Nasal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Nasal). Monitor therapy

Fluticasone (Oral Inhalation): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Fluticasone (Oral Inhalation). Management: Use of orally inhaled fluticasone propionate with strong CYP3A4 inhibitors is not recommended. Use of orally inhaled fluticasone furoate with strong CYP3A4 inhibitors should be done with caution. Monitor patients using such a combination more closely. Consider therapy modification

Fusidic Acid (Systemic): May increase the serum concentration of CYP3A4 Substrates. Avoid combination

Gefitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Gefitinib. Monitor therapy

GuanFACINE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of GuanFACINE. Management: Reduce the guanfacine dose by 50% when initiating this combination. Consider therapy modification

Halofantrine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Halofantrine. Avoid combination

HYDROcodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of HYDROcodone. Monitor therapy

Ibrutinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ibrutinib. Management: If a strong CYP3A inhibitor must be used short-term (e.g. antifungals and antibiotics for 7 days or less), consider stopping ibrutinib until the CYP3A inhibitor is no longer needed. Avoid combination

Idelalisib: May increase the serum concentration of CYP3A4 Substrates. Avoid combination

Ifosfamide: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ifosfamide. Monitor therapy

Iloperidone: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Iloperidone. Specifically, concentrations of the metabolites P88 and P95 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Iloperidone. Management: Reduce iloperidone dose by half when administered with a strong CYP3A4 inhibitor. Consider therapy modification

Imatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imatinib. Monitor therapy

Imatinib: May increase the serum concentration of CYP2D6 Substrates. Monitor therapy

Imidafenacin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Imidafenacin. Monitor therapy

Irinotecan Products: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Irinotecan Products. Specifically, serum concentrations of SN-38 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Irinotecan Products. Avoid combination

Isavuconazonium Sulfate: CYP3A4 Inhibitors (Strong) may increase serum concentrations of the active metabolite(s) of Isavuconazonium Sulfate. Specifically, CYP3A4 Inhibitors (Strong) may increase isavuconazole serum concentrations. Management: Combined use is considered contraindicated per US labeling. Lopinavir/ritonavir (and possibly other uses of ritonavir doses less than 400 mg every 12 hours) is treated as a possible exception to this contraindication despite strongly inhibiting CYP3A4. Avoid combination

Ivabradine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivabradine. Avoid combination

Ivacaftor: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ivacaftor. Management: Ivacaftor dose reductions are required; consult prescribing information for specific age- and weight-based recommendations. Consider therapy modification

Ixabepilone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ixabepilone. Consider therapy modification

Lacosamide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lacosamide. Monitor therapy

Lapatinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lapatinib. Management: If an overlap in therapy cannot be avoided, consider reducing lapatinib adult dose to 500 mg/day during, and within 1 week of completing, treatment with the strong CYP3A4 inhibitor. Avoid combination

Lercanidipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lercanidipine. Avoid combination

Levobupivacaine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levobupivacaine. Monitor therapy

Levomilnacipran: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Levomilnacipran. Management: Do not exceed a maximum adult levomilnacipran dose of 80 mg/day in patients also receiving strong CYP3A4 inhibitors. Consider therapy modification

Linezolid: May enhance the serotonergic effect of Nefazodone. This could result in serotonin syndrome. Avoid combination

Lomitapide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lomitapide. Avoid combination

Lovastatin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lovastatin. Avoid combination

Luliconazole: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy

Lumefantrine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lumefantrine. Monitor therapy

Lumefantrine: May increase the serum concentration of CYP2D6 Substrates. Monitor therapy

Lurasidone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Lurasidone. Avoid combination

Macitentan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Macitentan. Avoid combination

MAO Inhibitors: May enhance the adverse/toxic effect of Antidepressants (Serotonin Reuptake Inhibitor/Antagonist). While methylene blue and linezolid are expected to interact, specific recommendations for their use differ from other monoamine oxidase inhibitors. Refer to monographs specific to those agents for details. Exceptions: Linezolid; Methylene Blue; Tedizolid. Avoid combination

Maraviroc: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Maraviroc. Management: Reduce the adult dose of maraviroc to 150 mg twice daily when used with a strong CYP3A4 inhibitor. Do not use maraviroc with strong CYP3A4 inhibitors in patients with Clcr less than 30 mL/min. Consider therapy modification

MedroxyPROGESTERone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MedroxyPROGESTERone. Monitor therapy

Metaxalone: May enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Monitor therapy

Methylene Blue: Nefazodone may enhance the serotonergic effect of Methylene Blue. This could result in serotonin syndrome. Avoid combination

MethylPREDNISolone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MethylPREDNISolone. Management: Consider methylprednisolone dose reduction in patients receiving strong CYP3A4 inhibitors and monitor for increased steroid related adverse effects. Consider therapy modification

Metoclopramide: Serotonin Modulators may enhance the adverse/toxic effect of Metoclopramide. This may be manifest as symptoms consistent with serotonin syndrome or neuroleptic malignant syndrome. Monitor therapy

MiFEPRIStone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of MiFEPRIStone. Management: Limit mifepristone adult dose, when used for treatment of hyperglycemia in Cushing's syndrome, to a maximum of 300 mg/day when combined with a strong CYP3A4 inhibitor. Monitor for increased mifepristone toxicity regardless of dose or indication. Consider therapy modification

MiFEPRIStone: May increase the serum concentration of CYP3A4 Substrates. Management: Minimize doses of CYP3A4 substrates, and monitor for increased concentrations/toxicity, during and 2 weeks following treatment with mifepristone. Avoid cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus. Consider therapy modification

Mirodenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Mirodenafil. Management: Consider using a lower dose of mirodenafil when used with strong CYP3A4 inhibitors. Monitor for increased mirodenafil effects/toxicities with the use of this combination. Consider therapy modification

Mitotane: May decrease the serum concentration of CYP3A4 Substrates. Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification

Naloxegol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Naloxegol. Avoid combination

Netupitant: May increase the serum concentration of CYP3A4 Substrates. Monitor therapy

Nilotinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nilotinib. Avoid combination

NiMODipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of NiMODipine. Avoid combination

Nisoldipine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Nisoldipine. Avoid combination

Olaparib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Olaparib. Management: Avoid use of strong CYP3A4 inhibitors in patients being treated with olaparib. If such concurrent use cannot be avoided, the dose of olaparib should be reduced to 150 mg twice daily. Avoid combination

Ospemifene: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ospemifene. Monitor therapy

Oxybutynin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Oxybutynin. Monitor therapy

OxyCODONE: CYP3A4 Inhibitors (Strong) may enhance the adverse/toxic effect of OxyCODONE. CYP3A4 Inhibitors (Strong) may increase the serum concentration of OxyCODONE. Serum concentrations of the active metabolite oxymorphone may also be increased. Consider therapy modification

Palbociclib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Palbociclib. Avoid combination

Panobinostat: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Panobinostat. Management: Reduce the panobinostat dose to 10 mg when it must be used with a strong CYP3A4 inhibitor. Consider therapy modification

Panobinostat: May increase the serum concentration of CYP2D6 Substrates. Management: Avoid concurrent use of sensitive CYP2D6 substrates when possible, particularly those substrates with a narrow therapeutic index. Consider therapy modification

Parecoxib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Parecoxib. Monitor therapy

Paricalcitol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Paricalcitol. Monitor therapy

PAZOPanib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PAZOPanib. Management: Avoid concurrent use of pazopanib with strong inhibitors of CYP3A4 whenever possible. If it is not possible to avoid such a combination, reduce pazopanib adult dose to 400 mg. Further dose reductions may also be required. Consider therapy modification

Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates. Peginterferon Alfa-2b may increase the serum concentration of CYP2D6 Substrates. Monitor therapy

Perhexiline: CYP2D6 Substrates may increase the serum concentration of Perhexiline. Perhexiline may increase the serum concentration of CYP2D6 Substrates. Monitor therapy

Pimavanserin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pimavanserin. Consider therapy modification

Pimecrolimus: CYP3A4 Inhibitors (Strong) may decrease the metabolism of Pimecrolimus. Monitor therapy

Pimozide: Nefazodone may increase the serum concentration of Pimozide. Avoid combination

PONATinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PONATinib. Management: Per ponatinib U.S. prescribing information, the adult starting dose of ponatinib should be reduced to 30 mg daily during treatment with any strong CYP3A4 inhibitor. Consider therapy modification

Pranlukast: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Pranlukast. Monitor therapy

Prasugrel: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Prasugrel. Monitor therapy

Praziquantel: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Praziquantel. Monitor therapy

PrednisoLONE (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of PrednisoLONE (Systemic). Monitor therapy

PredniSONE: CYP3A4 Inhibitors (Strong) may increase the serum concentration of PredniSONE. Monitor therapy

Propafenone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Propafenone. Monitor therapy

Protease Inhibitors: May increase the serum concentration of Nefazodone. Management: Consider alternatives to, or reduced doses of, nefazodone in patients treated with HIV protease inhibitors. Monitor patients receiving these combinations closely for toxic effects of nefazodone. Consider therapy modification

QUEtiapine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of QUEtiapine. Management: In quetiapine treated patients, reduce the quetiapine dose to one sixth of the regular dose following strong CYP3A4 inhibitor initiation. In patients receiving strong CYP3A4 inhibitors, initiate quetiapine at the lowest dose and up-titrate as needed. Consider therapy modification

Ramelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ramelteon. Monitor therapy

Ranolazine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ranolazine. Avoid combination

Reboxetine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Reboxetine. Consider therapy modification

Red Yeast Rice: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Red Yeast Rice. Specifically, concentrations of lovastatin and related compounds found in Red Yeast Rice may be increased. Avoid combination

Regorafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Regorafenib. Avoid combination

Repaglinide: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Repaglinide. Management: The addition of a CYP2C8 inhibitor to this drug combination may substantially increase the magnitude of increase in repaglinide exposure. Monitor therapy

Retapamulin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Retapamulin. Management: Avoid this combination in patients less than 2 years old. No action is required in other populations. Monitor therapy

Rilpivirine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Rilpivirine. Monitor therapy

RomiDEPsin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of RomiDEPsin. Monitor therapy

Ruxolitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ruxolitinib. Management: This combination should be avoided under some circumstances. See monograph for details. Consider therapy modification

Salmeterol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Salmeterol. Avoid combination

SAXagliptin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SAXagliptin. Management: Saxagliptin U.S. product labeling recommends limiting saxagliptin adult dose to 2.5 mg/day when used with a strong CYP3A4 inhibitor. Monitor for increased saxagliptin levels/effects. A similar recommendation is not made in the Canadian product labeling. Consider therapy modification

Selective Serotonin Reuptake Inhibitors: May enhance the serotonergic effect of Antidepressants (Serotonin Reuptake Inhibitor/Antagonist). This may cause serotonin syndrome. Management: Consider alternatives, and use conservative initial dosing. Monitor patients receiving these combinations for signs/symptoms of serotonin toxicity. Consider therapy modification

Serotonin Modulators: May enhance the adverse/toxic effect of other Serotonin Modulators. The development of serotonin syndrome may occur. Exceptions: Nicergoline; Tedizolid. Monitor therapy

Sildenafil: Nefazodone may increase the serum concentration of Sildenafil. Consider therapy modification

Silodosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Silodosin. Avoid combination

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Simeprevir: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simeprevir. Avoid combination

Simvastatin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Simvastatin. Avoid combination

Sonidegib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Sonidegib. Avoid combination

SORAfenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of SORAfenib. Monitor therapy

St John's Wort: May decrease the serum concentration of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

Stiripentol: May increase the serum concentration of CYP3A4 Substrates. Management: Use of stiripentol with CYP3A4 substrates that are considered to have a narrow therapeutic index should be avoided due to the increased risk for adverse effects and toxicity. Any CYP3A4 substrate used with stiripentol requires closer monitoring. Consider therapy modification

Suvorexant: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Suvorexant. Avoid combination

Tacrolimus (Systemic): Antidepressants (Serotonin Reuptake Inhibitor/Antagonist) may decrease the metabolism of Tacrolimus (Systemic). Consider therapy modification

Tacrolimus (Systemic): CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tacrolimus (Systemic). Management: Monitor clinical tacrolimus response closely and frequently monitor tacrolimus serum concentrations with concurrent use of any strong CYP3A4 inhibitor. Tacrolimus dose reductions and/or prolongation of the dosing interval will likely be required. Consider therapy modification

Tacrolimus (Topical): Antidepressants (Serotonin Reuptake Inhibitor/Antagonist) may decrease the metabolism of Tacrolimus (Topical). Monitor therapy

Tadalafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tadalafil. Management: Recommendations regarding use of tadalafil in patients also receiving strong CYP3A4 inhibitors may vary based on indication and/or international labeling. Consult appropriate product labeling. Consider therapy modification

Tamsulosin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tamsulosin. Avoid combination

Tasimelteon: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tasimelteon. Monitor therapy

Tedizolid: May enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Monitor therapy

Terfenadine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Terfenadine. Avoid combination

Tetrahydrocannabinol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tetrahydrocannabinol. Monitor therapy

Ticagrelor: CYP3A4 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Ticagrelor. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ticagrelor. Avoid combination

TiZANidine: CYP1A2 Inhibitors (Weak) may increase the serum concentration of TiZANidine. Management: Avoid these combinations when possible. If combined use cannot be avoided, initiate tizanidine at an adult dose of 2 mg and increase in 2-4 mg increments based on patient response. Monitor for increased effects of tizanidine, including adverse reactions. Consider therapy modification

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Tofacitinib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tofacitinib. Management: Reduce the adult dose of tofacitinib to 5 mg daily in patients receiving strong CYP3A4 inhibitors. Consider therapy modification

Tolterodine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolterodine. Management: The maximum recommended adult dose of tolterodine is 2 mg/day when used together with a strong CYP3A4 inhibitor. Consider therapy modification

Tolvaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Tolvaptan. Avoid combination

Toremifene: CYP3A4 Inhibitors (Strong) may enhance the adverse/toxic effect of Toremifene. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Toremifene. Avoid combination

Trabectedin: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Trabectedin. Avoid combination

TraMADol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of TraMADol. Monitor therapy

TraMADol: Serotonin Modulators may enhance the adverse/toxic effect of TraMADol. The risk of seizures may be increased. TraMADol may enhance the serotonergic effect of Serotonin Modulators. This could result in serotonin syndrome. Monitor therapy

Udenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Udenafil. Avoid combination

Ulipristal: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Ulipristal. Management: This is specific for when ulipristal is being used for signs/symptoms of uterine fibroids (Canadian indication). When ulipristal is used as an emergency contraceptive, patients receiving this combo should be monitored for ulipristal toxicity. Avoid combination

Vardenafil: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vardenafil. Management: Recommendations regarding concomitant use of vardenafil with strong CYP3A4 inhibitors may vary depending on brand name (e.g., Levitra, Staxyn) or by international labeling. See full drug interaction monograph for details. Consider therapy modification

Vemurafenib: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vemurafenib. Avoid combination

Venetoclax: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Venetoclax. Management: These combinations are contraindicated during venetoclax initiation and ramp-up. In patients receiving steady venetoclax doses after completing ramp-up, reduce the venetoclax by at least 75% if strong CYP3A4 inhibitor use cannot be avoided. Consider therapy modification

Vilazodone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vilazodone. Management: Limit maximum adult vilazodone dose to 20 mg/day in patients receiving strong CYP3A4 inhibitors. The original vilazodone dose can be resumed following discontinuation of the strong CYP3A4 inhibitor. Consider therapy modification

VinCRIStine (Liposomal): CYP3A4 Inhibitors (Strong) may increase the serum concentration of VinCRIStine (Liposomal). Avoid combination

Vindesine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vindesine. Monitor therapy

Vinflunine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinflunine. Avoid combination

Vinorelbine: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vinorelbine. Monitor therapy

Vorapaxar: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Vorapaxar. Avoid combination

Zolpidem: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zolpidem. Monitor therapy

Zopiclone: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zopiclone. Management: The initial starting adult dose of zopiclone should not exceed 3.75 mg if combined with a strong CYP3A4 inhibitor. Monitor patients for signs and symptoms of zopiclone toxicity if these agents are combined. Consider therapy modification

Zuclopenthixol: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Zuclopenthixol. Management: Consider zuclopenthixol dosage reduction with concomitant use of a strong CYP3A4 inhibitor (eg, ketoconazole) in poor CYP2D6 metabolizers or with strong CYP2D6 inhibitors (eg, paroxetine). Monitor for increased zuclopenthixol levels/toxicity. Consider therapy modification

Adverse Reactions

>10%:

Central nervous system: Agitation, dizziness, drowsiness, headache, insomnia

Gastrointestinal: Constipation, nausea, xerostomia

Neuromuscular & skeletal: Weakness

1% to 10%:

Cardiovascular: Bradycardia, hypotension, orthostatic hypotension, peripheral edema, vasodilation

Central nervous system: Abnormal dreams, ataxia, chills, confusion, hypertonia, lack of concentration, memory impairment, paresthesia, psychomotor retardation

Dermatologic: Pruritus, skin rash

Endocrine & metabolic: Decreased libido, increased thirst

Gastrointestinal: Diarrhea, dysgeusia, dyspepsia, gastroenteritis, increased appetite, vomiting

Genitourinary: Impotence, mastalgia, urinary frequency, urinary retention

Hematologic & oncologic: Decreased hematocrit

Infection: Infection

Neuromuscular & skeletal: Arthralgia, neck stiffness, tremor

Ophthalmic: Blurred vision (9%), visual disturbance (7%), eye pain, visual field defect

Otic: Tinnitus

Respiratory: Bronchitis, cough, dyspnea, flu-like symptoms, pharyngitis

Miscellaneous: Fever

<1% (Limited to important or life-threatening): Abnormal liver function tests, angioedema, angle-closure glaucoma, atrioventricular block, galactorrhea, gynecomastia, hallucination, hepatic failure, hepatic necrosis, hepatitis, hypersensitivity reaction, hyponatremia, impotence, increased serum prolactin, leukopenia, priapism, rhabdomyolysis (with lovastatin/simvastatin), seizure, serotonin syndrome, skin photosensitivity, Stevens-Johnson syndrome, thrombocytopenia

ALERT: U.S. Boxed Warning

Suicidality and antidepressants:

Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of nefazodone or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared with placebo in adults older than 24 years; there was a reduction in risk with antidepressants compared with placebo in adults 65 years and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Monitor patients of all ages who are started on antidepressant therapy appropriately and observe them closely for clinical worsening, suicidality, or unusual changes in behavior. Advise families and caregivers of the need for close observation and communication with the health care provider. Nefazodone is not approved for use in pediatric patients.

Hepatotoxicity:

Cases of life-threatening hepatic failure have been reported in patients treated with nefazodone. The reported rate in the United States is approximately 1 case of liver failure resulting in death or transplant per 250,000 to 300,000 patient-years of nefazodone treatment. The total patient-years is a summation of each patient's duration of exposure expressed in years. For example, 1 patient-year is equal to 2 patients each treated for 6 months, 3 patients each treated for 4 months, etc.

Ordinarily, treatment with nefazodone should not be initiated in individuals with active liver disease or with elevated baseline serum transaminases. There is no evidence that preexisting liver disease increases the likelihood of developing liver failure; however, baseline abnormalities can complicate patient monitoring.

Advise patients to be alert for signs and symptoms of liver dysfunction (eg, jaundice, anorexia, GI complaints, malaise) and to report them to their health care provider immediately if they occur.

Discontinue nefazodone if clinical signs or symptoms suggest liver failure. If nefazodone-treated patients develop evidence of hepatocellular injury, such as increased serum AST or serum ALT levels at least 3 times the upper limit of normal, withdraw the drug. Presume these patients to be at increased risk for liver injury if nefazodone is reintroduced. Accordingly, do not consider such patients for re-treatment.

Warnings/Precautions

Major psychiatric warnings:

• Suicidal thinking/behavior: [U.S. Boxed Warning]: Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults (18-24 years of age) with major depressive disorder (MDD) and other psychiatric disorders; consider risk prior to prescribing. Short-term studies did not show an increased risk in patients >24 years of age and showed a decreased risk in patients ≥65 years. Closely monitor patients for clinical worsening, suicidality, or unusual changes in behavior, particularly during the initial 1-2 months of therapy or during periods of dosage adjustments (increases or decreases); the patient’s family or caregiver should be instructed to closely observe the patient and communicate condition with healthcare provider. A medication guide concerning the use of antidepressants should be dispensed with each prescription. Nefazodone is not FDA approved for use in children.

• The possibility of a suicide attempt is inherent in major depression and may persist until remission occurs. Patients treated with antidepressants should be observed for clinical worsening and suicidality, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decreases. Worsening depression and severe abrupt suicidality that are not part of the presenting symptoms may require discontinuation or modification of drug therapy. Use caution in high-risk patients during initiation of therapy.

• Prescriptions should be written for the smallest quantity consistent with good patient care. The patient's family or caregiver should be alerted to monitor patients for the emergence of suicidality and associated behaviors such as anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity, akathisia, hypomania, and mania; patients should be instructed to notify their healthcare provider if any of these symptoms or worsening depression or psychosis occur.

Concerns related to adverse effects:

• Anticholinergic effects: May cause anticholinergic effects (constipation, xerostomia, blurred vision, urinary retention); use with caution in patients with decreased gastrointestinal motility, paralytic ileus, urinary retention, BPH, xerostomia, or visual problems. The degree of anticholinergic blockade produced by this agent is very low relative to other antidepressants (APA, 2010).

• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery or driving). The degree of sedation is moderate relative to other antidepressants (Bauer, 2013).

• Fractures: Bone fractures have been associated with antidepressant treatment. Consider the possibility of a fragility fracture if an antidepressant-treated patient presents with unexplained bone pain, point tenderness, swelling, or bruising (Rabenda, 2013; Rizzoli, 2012).

• Hepatic failure: [U.S. Boxed Warning]: Cases of life-threatening hepatic failure have been reported. Discontinue if clinical signs or symptoms (such as increased serum AST or ALT levels greater than 3 times the upper limit of normal) suggest liver failure. The time to liver injury in reported, severe cases ranged from 2 weeks to 6 months; not all cases had a clear prodromal onset of symptoms. Patients who develop symptoms while on nefazodone should not be considered for re-treatment. Treatment should not ordinarily be initiated in patients with active liver disease or elevated baseline serum transaminases.

• Ocular effects: May cause mild pupillary dilation which in susceptible individuals can lead to an episode of narrow-angle glaucoma. Consider evaluating patients who have not had an iridectomy for narrow-angle glaucoma risk factors.

• Orthostatic hypotension: May cause orthostatic hypotension (risk is low relative to other antidepressants); use with caution in patients at risk of this effect or in those who would not tolerate transient hypotensive episodes (cerebrovascular disease, cardiovascular disease, dehydration, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia).

• Sexual dysfunction: Rare reports of priapism have occurred. The incidence of sexual dysfunction with nefazodone is generally lower than with SSRIs (APA, 2010; Bauer, 2013).

Disease-related concerns:

• Cardiovascular disease: Use with caution in patients with a history of cardiovascular disease (including previous MI, stroke, tachycardia, or conduction abnormalities); the risk conduction abnormalities with this agent is very low relative to other antidepressants (APA 2010; Bauer, 2013).

• Hepatic impairment: [U.S. Boxed Warning]: Treatment should not ordinarily be initiated in patients with active liver disease or elevated baseline serum transaminases. Use with caution in patients with hepatic impairment.

• Mania/hypomania: May precipitate a shift to mania or hypomania in patients with bipolar disorder. Monotherapy in patients with bipolar disorder should be avoided. Patients presenting with depressive symptoms should be screened for bipolar disorder, including details regarding family history of suicide, bipolar disorder, and depression. Nefazodone is not FDA approved for the treatment of bipolar depression.

• Renal impairment: Use with caution in patients with renal impairment.

• Seizure disorder: Use with caution in patients at risk of seizures, including those with a history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications which may lower seizure threshold.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Elderly: Use with caution in the elderly.

Other warnings/precautions:

• Discontinuation syndrome: Abrupt discontinuation or interruption of antidepressant therapy has been associated with a discontinuation syndrome. Symptoms arising may vary with antidepressant however commonly include nausea, vomiting, diarrhea, headaches, lightheadedness, dizziness, diminished appetite, sweating, chills, tremors, paresthesias, fatigue, somnolence, and sleep disturbances (eg, vivid dreams, insomnia). Less common symptoms include electric shock-like sensations, cardiac arrhythmias (more common with tricyclic antidepressants), myalgias, parkinsonism, arthralgias, and balance difficulties. Psychological symptoms may also emerge such as agitation, anxiety, akathisia, panic attacks, irritability, aggressiveness, worsening of mood, dysphoria, mood lability, hyperactivity, mania/hypomania, depersonalization, decreased concentration, slowed thinking, confusion, and memory or concentration difficulties. Greater risks for developing a discontinuation syndrome have been associated with antidepressants with shorter half-lives, longer durations of treatment, and abrupt discontinuation.. For antidepressants of short or intermediate half-lives, symptoms may emerge within 2-5 days after treatment discontinuation and last 7-14 days (APA, 2010; Fava, 2006; Haddad, 2001; Shelton, 2001; Warner, 2006).

Monitoring Parameters

Liver function tests (baseline and periodic; if AST/ALT increase >3 times ULN, the drug should be discontinued and not reintroduced; mental status, suicide ideation (especially at the beginning of therapy or when doses are increased or decreased), anxiety, social functioning, mania, panic attacks, or other unusual changes in behavior

Pregnancy Risk Factor

C

Pregnancy Considerations

Adverse effects were observed in some animal reproduction studies. When nefazodone is taken during pregnancy, an increased risk of major malformations has not been observed in the limited number of pregnancies studied (Einarson 2003; Einarson 2009). The long-term effects of in utero exposure to nefazodone on infant development and behavior are not known.

The ACOG recommends that therapy with antidepressants during pregnancy be individualized; treatment of depression during pregnancy should incorporate the clinical expertise of the mental health clinician, obstetrician, primary health care provider, and pediatrician. According to the American Psychiatric Association (APA), the risks of medication treatment should be weighed against other treatment options and untreated depression. Consideration should be given to using agents with safety data in pregnancy. For women who discontinue antidepressant medications during pregnancy and who may be at high risk for postpartum depression, the medications can be restarted following delivery. Treatment algorithms have been developed by the ACOG and the APA for the management of depression in women prior to conception and during pregnancy (ACOG 2008; APA 2010; Yonkers 2009).

Pregnant women exposed to antidepressants during pregnancy are encouraged to enroll in the National Pregnancy Registry for Antidepressants (NPRAD). Women 18 to 45 years of age or their health care providers may contact the registry by calling 844-405-6185. Enrollment should be done as early in pregnancy as possible.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience headache, asthenia, dyspepsia, constipation, diarrhea, polyphagia, xerostomia, or insomnia. Have patient report immediately to prescriber suicidal ideation, severe dizziness, syncope, illogical thinking, paresthesia, loss of libido, chills, pharyngitis, memory impairments, intolerable fatigue, or priapism (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

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