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Interactions between Chlorpheniramine / phenylephrine and Trazodone

1 drug interaction and 43 additional warnings found for the following 2 drugs:

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Drug interactions

Moderate drug interactions

Moderate:

chlorpheniramine traZODone

Applies to: chlorpheniramine / phenylephrine and trazodone
Monitor

Central nervous system- and/or respiratory-depressant effects may be additively or synergistically increased in patients taking multiple drugs that cause these effects, especially in elderly or debilitated patients. Sedation and impairment of attention, judgment, thinking, and psychomotor skills may increase.

Management

During concomitant use of these drugs, patients should be monitored for potentially excessive or prolonged CNS and respiratory depression. Cautious dosage titration may be required, particularly at treatment initiation. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References (36)
  1. Hamilton MJ, Bush M, Smith P, Peck AW (1982) "The effects of bupropion, a new antidepressant drug, and diazepam, and their interaction in man." Br J Clin Pharmacol, 14, p. 791-7
  2. Stambaugh JE, Lane C (1983) "Analgesic efficacy and pharmacokinetic evaluation of meperidine and hydroxyzine, alone and in combination." Cancer Invest, 1, p. 111-7
  3. Sotaniemi EA, Anttila M, Rautio A, et al. (1981) "Propranolol and sotalol metabolism after a drinking party." Clin Pharmacol Ther, 29, p. 705-10
  4. Grabowski BS, Cady WJ, Young WW, Emery JF (1980) "Effects of acute alcohol administration on propranolol absorption." Int J Clin Pharmacol Ther Toxicol, 18, p. 317-9
  5. Lemberger L, Rowe H, Bosomworth JC, Tenbarge JB, Bergstrom RF (1988) "The effect of fluoxetine on the pharmacokinetics and psychomotor responses of diazepam." Clin Pharmacol Ther, 43, p. 412-9
  6. MacLeod SM, Giles HG, Patzalek G, Thiessen JJ, Sellers EM (1977) "Diazepam actions and plasma concentrations following ethanol ingestion." Eur J Clin Pharmacol, 11, p. 345-9
  7. Divoll M, Greenblatt DJ, Lacasse Y, Shader RI (1981) "Benzodiazepine overdosage: plasma concentrations and clinical outcome." Psychopharmacology (Berl), 73, p. 381-3
  8. Naylor GJ, McHarg A (1977) "Profound hypothermia on combined lithium carbonate and diazepam treatment." Br Med J, 2, p. 22
  9. Stovner J, Endresen R (1965) "Intravenous anaesthesia with diazepam." Acta Anaesthesiol Scand, 24, p. 223-7
  10. Driessen JJ, Vree TB, Booij LH, van der Pol FM, Crul JF (1984) "Effect of some benzodiazepines on peripheral neuromuscular function in the rat in-vitro hemidiaphragm preparation." J Pharm Pharmacol, 36, p. 244-7
  11. Feldman SA, Crawley BE (1970) "Interaction of diazepam with the muscle-relaxant drugs." Br Med J, 1, p. 336-8
  12. Ochs HR, Greenblatt DJ, Verburg-Ochs B (1984) "Propranolol interactions with diazepam, lorazepam and alprazolam." Clin Pharmacol Ther, 36, p. 451-5
  13. Desager JP, Hulhoven R, Harvengt C, Hermann P, Guillet P, Thiercelin JF (1988) "Possible interactions between zolpidem, a new sleep inducer and chlorpromazine, a phenothiazine neuroleptic." Psychopharmacology (Berl), 96, p. 63-6
  14. Tverskoy M, Fleyshman G, Ezry J, Bradley EL, Jr Kissin I (1989) "Midazolam-morphine sedative interaction in patients." Anesth Analg, 68, p. 282-5
  15. "Product Information. Iopidine (apraclonidine ophthalmic)." Alcon Laboratories Inc
  16. Greiff JMC, Rowbotham D (1994) "Pharmacokinetic drug interactions with gastrointestinal motility modifying agents." Clin Pharmacokinet, 27, p. 447-61
  17. Greb WH, Buscher G, Dierdorf HD, Koster FE, Wolf D, Mellows G (1989) "The effect of liver enzyme inhibition by cimetidine and enzyme induction by phenobarbitone on the pharmacokinetics of paroxetine." Acta Psychiatr Scand, 80 Suppl, p. 95-8
  18. Markowitz JS, Wells BG, Carson WH (1995) "Interactions between antipsychotic and antihypertensive drugs." Ann Pharmacother, 29, p. 603-9
  19. (2001) "Product Information. Ultram (tramadol)." McNeil Pharmaceutical
  20. (2001) "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories
  21. (2001) "Product Information. Ultiva (remifentanil)." Mylan Institutional (formally Bioniche Pharma USA Inc)
  22. (2001) "Product Information. Seroquel (quetiapine)." Astra-Zeneca Pharmaceuticals
  23. (2001) "Product Information. Meridia (sibutramine)." Knoll Pharmaceutical Company
  24. (2001) "Product Information. Tasmar (tolcapone)." Valeant Pharmaceuticals
  25. Miller LG (1998) "Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interactions." Arch Intern Med, 158, p. 2200-11
  26. (2001) "Product Information. Precedex (dexmedetomidine)." Abbott Pharmaceutical
  27. (2001) "Product Information. Trileptal (oxcarbazepine)." Novartis Pharmaceuticals
  28. Ferslew KE, Hagardorn AN, McCormick WF (1990) "A fatal interaction of methocarbamol and ethanol in an accidental poisoning." J Forensic Sci, 35, p. 477-82
  29. Plushner SL (2000) "Valerian: valeriana officinalis." Am J Health Syst Pharm, 57, p. 328-35
  30. (2002) "Product Information. Xatral (alfuzosin)." Sanofi-Synthelabo Canada Inc
  31. (2002) "Product Information. Lexapro (escitalopram)." Forest Pharmaceuticals
  32. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  33. Cerner Multum, Inc. "Australian Product Information."
  34. (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
  35. (2014) "Product Information. Belsomra (suvorexant)." Merck & Co., Inc
  36. (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka America Pharmaceutical, Inc.

Food/lifestyle interactions

Moderate food/lifestyle interactions

Moderate:

chlorpheniramine Food/Lifestyle

Applies to: chlorpheniramine / phenylephrine
Generally avoid

Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

Management

Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References (4)
  1. Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
  2. Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
  3. (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
  4. (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka America Pharmaceutical, Inc.
Moderate:

traZODone Food/Lifestyle

Applies to: trazodone
Generally avoid

Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

Management

Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References (4)
  1. Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
  2. Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
  3. (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
  4. (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka America Pharmaceutical, Inc.
Moderate:

phenylephrine Caffeine

Applies to: chlorpheniramine / phenylephrine
Monitor

Coadministration of two or more sympathomimetic or noradrenergic agents may increase the risk of nervousness, irritability, tachycardia, and/or increased blood pressure. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic and/or noradrenergic agents, including norepinephrine transporter inhibitors. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

Management

Caution is advised if two or more sympathomimetic or noradrenergic agents are coadministered. Pulse and blood pressure should be closely monitored. Consultation with individual product labeling, as well as relevant institutional protocols, may be advisable for further guidance.

References (20)
  1. Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
  2. Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
  3. (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
  4. (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
  5. (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
  6. (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
  7. (2024) "Product Information. Ephedrine (ephedrine)." Hameln Pharma Ltd
  8. (2023) "Product Information. Ephedrine Hydrochloride (ephedrine)." Wockhardt UK Ltd
  9. (2026) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
  10. (2025) "Product Information. Atomoxetine (atomoxetine)." Zentiva Pharma UK Ltd
  11. (2026) "Product Information. Atomoxetine (Apo) (atomoxetine)." Arrotex Pharmaceuticals Pty Ltd
  12. Angita Pharma, Inc (2026) AG-ATOMOXETINE Product Monograph (Health Canada) https://pdf.hres.ca/dpd_pm/00059014.PDF
  13. (2026) "Product Information. Boots Decongestant (Pseudoephedrine) (pseudoephedrine)." The Boots Company Plc
  14. (2023) "Product Information. Sinus and Nasal Decongestant (Trust) (pseudoephedrine)." Noumed Pharmaceuticals Pty Ltd
  15. (2019) "Product Information. Ephedrine (ephedrine)." Pfizer Australia Pty Ltd
  16. (2024) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Amneal Pharmaceuticals LLC
  17. (2024) "Product Information. Lemsip Cough Max for Mucus Cough and Cold (guaifenesin/paracetamol/phenylephrine)." Reckitt Benckiser Healthcare (UK) Ltd
  18. emc (2026) Product information: sudafed plus blocked nose 1mg/50mg/ml nasal spray. https://www.medicines.org.uk/emc/product/14256/smpc?utm_source=chatgpt.com
  19. (2023) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Baxter Corporation
  20. Neo Health (OTC) Pty Ltd (2026) Product information: pseudoephedrine hydrochloride-paracetamol capsules. https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2024-PI-02603-1&d=20260804172310101&d=20260827172310101

Disease interactions

40 potential interactions Applies to: 29 conditions, including Depression, Bipolar Disorder, Asthma, Benign Prostatic Hyperplasia, and COPD.

Arrhythmia

Moderate:

trazodone

traZODone has a moderate potential interaction with Arrhythmia.

Although less cardiotoxic than the tricyclic antidepressants, trazodone may be arrhythmogenic in some patients with cardiac disease. The use of trazodone has been associated with the occurrence of arrhythmias, including PVCs, ventricular couplets, ventricular tachycardia, atrial fibrillation, and heart block. Myocardial infarction has been reported. Trazodone should not be used during the acute recovery phase following myocardial infarction, and should be administered only with extreme caution in patients with hyperthyroidism and/or cardiovascular disease. Close monitoring of cardiovascular status, including ECG changes, is recommended at all dosages. Many of the newer antidepressants, including bupropion and the selective serotonin reuptake inhibitors (SSRIs), are considerably less or minimally cardiotoxic and may be appropriate alternatives.

Asthma

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Asthma.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

Benign Prostatic Hyperplasia

Moderate:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a moderate potential interaction with Benign Prostatic Hyperplasia.

Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.

Bipolar Disorder

Moderate:

trazodone

traZODone has a moderate potential interaction with Bipolar Disorder.

All antidepressants may occasionally cause mania or hypomania, particularly in patients with bipolar disorder. Therapy with antidepressants should be administered cautiously in patients with a history of mania/hypomania.

Moderate:

trazodone

traZODone has a moderate potential interaction with Bipolar Disorder.

Adults, young adults and children patients with depression and other psychiatric disorders may experience worsening of their symptoms and may have the emergence of suicidal thoughts and behavior. Patients should be monitored appropriately and observed closely for worsening of their symptoms, suicidality or changes in their behavior, especially during the first few months of treatment, and at times of dose changes. Discontinuing the medication should be considered if symptoms are persistently worse, or abrupt in onset. Phenylpiperazine antidepressants are not approved for use in pediatric patients.

Cardiovascular Conditions and Disorders

Major:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a major potential interaction with Cardiovascular Conditions and Disorders.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Cardiovascular Conditions and Disorders.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Moderate:

trazodone

traZODone has a moderate potential interaction with Cardiovascular Conditions and Disorders.

Although less cardiotoxic than the tricyclic antidepressants, trazodone may be arrhythmogenic in some patients with cardiac disease. The use of trazodone has been associated with the occurrence of arrhythmias, including PVCs, ventricular couplets, ventricular tachycardia, atrial fibrillation, and heart block. Myocardial infarction has been reported. Trazodone should not be used during the acute recovery phase following myocardial infarction, and should be administered only with extreme caution in patients with hyperthyroidism and/or cardiovascular disease. Close monitoring of cardiovascular status, including ECG changes, is recommended at all dosages. Many of the newer antidepressants, including bupropion and the selective serotonin reuptake inhibitors (SSRIs), are considerably less or minimally cardiotoxic and may be appropriate alternatives.

Cerebrovascular Insufficiency

Major:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a major potential interaction with Cerebrovascular Insufficiency.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

Moderate:

trazodone

traZODone has a moderate potential interaction with Cerebrovascular Insufficiency.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

COPD

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with COPD.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

Dehydration

Moderate:

trazodone

traZODone has a moderate potential interaction with Dehydration.

Treatment with trazodone may cause hyponatremia, in many cases secondary to development of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Caution should be used when treating patients at greater risk of developing hyponatremia such as elderly patients, patients taking diuretics or those who are volume-depleted. Discontinuation of trazodone should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted.

Moderate:

trazodone

traZODone has a moderate potential interaction with Dehydration.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

Depression

Moderate:

trazodone

traZODone has a moderate potential interaction with Depression.

Adults, young adults and children patients with depression and other psychiatric disorders may experience worsening of their symptoms and may have the emergence of suicidal thoughts and behavior. Patients should be monitored appropriately and observed closely for worsening of their symptoms, suicidality or changes in their behavior, especially during the first few months of treatment, and at times of dose changes. Discontinuing the medication should be considered if symptoms are persistently worse, or abrupt in onset. Phenylpiperazine antidepressants are not approved for use in pediatric patients.

Diabetes Mellitus

Moderate:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a moderate potential interaction with Diabetes Mellitus.

Sympathomimetic agents may cause increases in blood glucose concentrations. These effects are usually transient and slight but may be significant with dosages higher than those normally recommended. Therapy with sympathomimetic agents should be administered cautiously in patients with diabetes mellitus. Closer monitoring of blood glucose concentrations may be appropriate.

Diarrhea

Moderate:

trazodone

traZODone has a moderate potential interaction with Diarrhea.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

Gastrointestinal Obstruction

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Gastrointestinal Obstruction.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

Glaucoma, Narrow Angle

Moderate:

trazodone

traZODone has a moderate potential interaction with Glaucoma, Narrow Angle.

Some antidepressants exert mydriatic activity that can induce increased intraocular pressure and result in angle-closure (narrow-angle) glaucoma in a patient with anatomically narrow angles who does not have a patent iridectomy. Prior to initiating therapy with these agents, patients should be examined to determine whether they are susceptible to angle closure, and have a prophylactic procedure (e.g., iridectomy), if they are susceptible. The use of these drugs in patients with untreated anatomically narrow angles should be avoided.

Glaucoma/Intraocular Hypertension

Moderate:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a moderate potential interaction with Glaucoma/Intraocular Hypertension.

Sympathomimetic agents can induce transient mydriasis via stimulation of alpha-1 adrenergic receptors. In patients with anatomically narrow angles or narrow-angle glaucoma, pupillary dilation can provoke an acute attack. In patients with other forms of glaucoma, mydriasis may occasionally increase intraocular pressure. Therapy with sympathomimetic agents should be administered cautiously in patients with or predisposed to glaucoma, particularly narrow-angle glaucoma.

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Glaucoma/Intraocular Hypertension.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

History - Cerebrovascular Disease

Moderate:

trazodone

traZODone has a moderate potential interaction with History - Cerebrovascular Disease.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

History - Myocardial Infarction

Moderate:

trazodone

traZODone has a moderate potential interaction with History - Myocardial Infarction.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

Hyperthyroidism

Major:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a major potential interaction with Hyperthyroidism.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Hyperthyroidism.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Moderate:

trazodone

traZODone has a moderate potential interaction with Hyperthyroidism.

Although less cardiotoxic than the tricyclic antidepressants, trazodone may be arrhythmogenic in some patients with cardiac disease. The use of trazodone has been associated with the occurrence of arrhythmias, including PVCs, ventricular couplets, ventricular tachycardia, atrial fibrillation, and heart block. Myocardial infarction has been reported. Trazodone should not be used during the acute recovery phase following myocardial infarction, and should be administered only with extreme caution in patients with hyperthyroidism and/or cardiovascular disease. Close monitoring of cardiovascular status, including ECG changes, is recommended at all dosages. Many of the newer antidepressants, including bupropion and the selective serotonin reuptake inhibitors (SSRIs), are considerably less or minimally cardiotoxic and may be appropriate alternatives.

Hyponatremia

Moderate:

trazodone

traZODone has a moderate potential interaction with Hyponatremia.

Treatment with trazodone may cause hyponatremia, in many cases secondary to development of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Caution should be used when treating patients at greater risk of developing hyponatremia such as elderly patients, patients taking diuretics or those who are volume-depleted. Discontinuation of trazodone should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted.

Hypotension

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Hypotension.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Moderate:

trazodone

traZODone has a moderate potential interaction with Hypotension.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

Ischemic Heart Disease

Moderate:

trazodone

traZODone has a moderate potential interaction with Ischemic Heart Disease.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

Liver Disease

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Liver Disease.

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

Moderate:

trazodone

traZODone has a moderate potential interaction with Liver Disease.

Trazodone undergoes metabolism in the liver. The metabolites, at least one of which is pharmacologically active, are excreted by the kidney. There are no data available concerning the pharmacokinetic disposition of trazodone or its metabolites in patients with renal and/or liver disease. Therapy with trazodone should be administered cautiously in patients with significantly impaired renal or hepatic function. Dosage adjustments may be necessary.

Mania

Moderate:

trazodone

traZODone has a moderate potential interaction with Mania.

All antidepressants may occasionally cause mania or hypomania, particularly in patients with bipolar disorder. Therapy with antidepressants should be administered cautiously in patients with a history of mania/hypomania.

Pheochromocytoma

Major:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a major potential interaction with Pheochromocytoma.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

Prostate Tumor, Benign

Moderate:

chlorpheniramine / phenylephrine

The phenylephrine in chlorpheniramine / phenylephrine has a moderate potential interaction with Prostate Tumor, Benign.

Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.

Renal Dysfunction

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Renal Dysfunction.

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

Moderate:

trazodone

traZODone has a moderate potential interaction with Renal Dysfunction.

Trazodone undergoes metabolism in the liver. The metabolites, at least one of which is pharmacologically active, are excreted by the kidney. There are no data available concerning the pharmacokinetic disposition of trazodone or its metabolites in patients with renal and/or liver disease. Therapy with trazodone should be administered cautiously in patients with significantly impaired renal or hepatic function. Dosage adjustments may be necessary.

Seizures

Moderate:

trazodone

traZODone has a moderate potential interaction with Seizures.

The use of most antidepressants is associated with a risk of seizures. There have been only rare reports of convulsions, including grand mal seizures, following the administration of nefazodone or trazodone. Although a causal relationship has not been established, therapy with these agents should be administered cautiously in patients with a history of seizures.

SIADH

Moderate:

trazodone

traZODone has a moderate potential interaction with SIADH.

Treatment with trazodone may cause hyponatremia, in many cases secondary to development of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Caution should be used when treating patients at greater risk of developing hyponatremia such as elderly patients, patients taking diuretics or those who are volume-depleted. Discontinuation of trazodone should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted.

Urinary Retention

Moderate:

chlorpheniramine / phenylephrine

The chlorpheniramine in chlorpheniramine / phenylephrine has a moderate potential interaction with Urinary Retention.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

Vomiting

Moderate:

trazodone

traZODone has a moderate potential interaction with Vomiting.

Trazodone has alpha-1 adrenergic blocking activity and may cause hypotension (including orthostatic hypotension) in approximately 5% of patients. Therapy with trazodone should be administered cautiously in patients with hypotension or conditions that could be exacerbated by hypotension, such as a history of myocardial infarction, angina, or ischemic stroke. Patients with dehydration (e.g., due to severe diarrhea or vomiting) may be predisposed to hypotension and should also be managed carefully during therapy with trazodone. Blood pressure should be monitored at regular intervals, particularly during dosage escalation or whenever dosage has been altered, and patients should be advised not to rise abruptly from a sitting or recumbent position.

More resources

chlorpheniramine / phenylephrine

A total of 531 drugs are known to interact with chlorpheniramine / phenylephrine.

trazodone

A total of 694 drugs are known to interact with trazodone.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.