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Dutasteride and Tamsulosin

Pronunciation

(doo TAS teer ide & tam SOO loe sin)

Index Terms

  • Dutasteride/Tamsulosin HCl
  • Tamsulosin and Dutasteride
  • Tamsulosin Hydrochloride and Dutasteride

Dosage Forms

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

Capsule, oral:

Jalyn: Dutasteride 0.5 mg and tamsulosin hydrochloride 0.4 mg

Generic: Dutasteride 0.5 mg and tamsulosin hydrochloride 0.4 mg

Brand Names: U.S.

  • Jalyn

Pharmacologic Category

  • 5 Alpha-Reductase Inhibitor
  • Alpha1 Blocker

Pharmacology

Dutasteride is a 4-azo analog of testosterone and is a competitive, selective inhibitor of both reproductive tissues (type 2) and skin and hepatic (type 1) 5α-reductase. This results in inhibition of the conversion of testosterone to dihydrotestosterone and markedly suppresses serum dihydrotestosterone levels.

Tamsulosin is an antagonist of alpha1A-adrenoreceptors in the prostate. Smooth muscle tone in the prostate is mediated by alpha1A-adrenoreceptors; blocking them leads to relaxation of smooth muscle in the bladder neck and prostate, causing an improvement of urine flow and decreased symptoms of BPH. Approximately 75% of the alpha1-receptors in the prostate are of the alpha1Asubtype.

Use: Labeled Indications

Benign prostatic hyperplasia: Treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate.

Limitations of use: Dutasteride-containing products are not approved for the prevention of prostate cancer.

Contraindications

Clinically significant hypersensitivity to dutasteride, tamsulosin, other 5-alpha-reductase inhibitors (eg, finasteride), or any component of the formulation; use in pediatric patients, women of childbearing potential, or in pregnancy

Dosing: Adult

Benign prostatic hyperplasia (BPH): Males: Oral: One capsule (0.5 mg dutasteride/0.4 mg tamsulosin) once daily ~30 minutes after the same meal each day

Dosing: Geriatric

Refer to adult dosing.

Dosing: Renal Impairment

CrCl ≥10 mL/minute/1.73 m2: No dosage adjustment necessary.

CrCl <10 mL/minute/1.73 m2: There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied).

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling. See individual agents.

Administration

Administer 30 minutes after the same meal each day. Capsules should be swallowed whole; do not crush, chew, or open. Oropharyngeal contact with capsule contents may result in irritation of the mucosa.

Hazardous agent; use appropriate precautions for handling and disposal (NIOSH 2014 [group 3]).

Storage

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).

Drug Interactions

Alpha-/Beta-Agonists: Alpha1-Blockers may diminish the vasoconstricting effect of Alpha-/Beta-Agonists. Similarly, Alpha-/Beta-Agonists may antagonize Alpha1-Blocker vasodilation. Monitor therapy

Alpha1-Agonists: Alpha1-Blockers may diminish the vasoconstricting effect of Alpha1-Agonists. Similarly, Alpha1-Agonists may antagonize Alpha1-Blocker vasodilation. Monitor therapy

Alpha1-Blockers: May enhance the antihypertensive effect of other Alpha1-Blockers. Avoid combination

Amifostine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Amifostine. Management: When amifostine is used at chemotherapy doses, blood pressure lowering medications should be withheld for 24 hours prior to amifostine administration. If blood pressure lowering therapy cannot be withheld, amifostine should not be administered. Consider therapy modification

Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may enhance the hypotensive effect of Antipsychotic Agents (Second Generation [Atypical]). Monitor therapy

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

Barbiturates: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Beta-Blockers: May enhance the orthostatic hypotensive effect of Alpha1-Blockers. The risk associated with ophthalmic products is probably less than systemic products. Exceptions: Levobunolol; Metipranolol. Monitor therapy

Blood Pressure Lowering Agents: May enhance the hypotensive effect of Hypotension-Associated Agents. Monitor therapy

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

Brimonidine (Topical): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Calcium Channel Blockers: Alpha1-Blockers may enhance the hypotensive effect of Calcium Channel Blockers. Monitor therapy

Cimetidine: May increase the serum concentration of Tamsulosin. Monitor therapy

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

CYP2D6 Inhibitors (Strong): May increase the serum concentration of Tamsulosin. Monitor therapy

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 increase the serum concentration of Tamsulosin. Avoid combination

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates. Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dapoxetine: May enhance the orthostatic hypotensive effect of Alpha1-Blockers. Monitor therapy

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

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

Diazoxide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

DULoxetine: Blood Pressure Lowering Agents may enhance the hypotensive effect of DULoxetine. Monitor therapy

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

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

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

Herbs (Hypotensive Properties): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Hypotension-Associated Agents: Blood Pressure Lowering Agents may enhance the hypotensive effect of Hypotension-Associated Agents. Monitor therapy

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

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

Levodopa: Blood Pressure Lowering Agents may enhance the hypotensive effect of Levodopa. Monitor therapy

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

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

Molsidomine: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

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

Nicorandil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Nitroprusside: Blood Pressure Lowering Agents may enhance the hypotensive effect of Nitroprusside. Monitor therapy

Obinutuzumab: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Management: Consider temporarily withholding blood pressure lowering medications beginning 12 hours prior to obinutuzumab infusion and continuing until 1 hour after the end of the infusion. Consider therapy modification

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

Pentoxifylline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Phosphodiesterase 5 Inhibitors: May enhance the hypotensive effect of Alpha1-Blockers. Management: Ensure patient is stable on one agent prior to initiating the other, and always initiate combination using the lowest possible dose of the drug being added. When tadalafil is used for treatment of BPH, concurrent alpha 1-blockers are not recommended. Consider therapy modification

Prostacyclin Analogues: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Quinagolide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

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

Simeprevir: May increase the serum concentration of CYP3A4 Substrates. 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

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

Test Interactions

PSA levels decrease in treated patients. After 3 months of therapy, PSA levels stabilize to a new baseline that is ~50% of pretreatment values. If following serial PSAs in a patient, re-establish a new baseline after ≥3 months of use. If interpreting an isolated PSA value in a patient treated for ≥3 months, then double the PSA value for comparison.

Adverse Reactions

Frequencies reported for when products used in combination. Also see individual agents.

1% to 10%:

Central nervous system: Dizziness (2%)

Endocrine & metabolic: Decreased libido (5% to 6%), breast changes (3% to 5%, including breast hypertrophy, breast swelling, breast tenderness, gynecomastia, mastalgia, nipple pain, nipple swelling)

Genitourinary: Ejaculatory disorder (10% to 11%), impotence (8% to 10%)

<1% (Limited to important or life-threatening): Malignant neoplasm of prostate (high-grade)

Warnings/Precautions

Concerns related to adverse effects:

• Floppy iris syndrome: Intraoperative floppy iris syndrome (IFIS) has been observed in cataract surgery patients who were on or were previously treated with alpha1-blockers, particularly with tamsulosin use (Abdel-Aziz 2009); in some cases, patients had discontinued the alpha1-blocker 5 weeks to 9 months prior to the surgery. The benefit of discontinuing alpha-blocker therapy prior to cataract surgery has not been established. IFIS may increase the risk of ocular complications during and after surgery. May require modifications to surgical technique; instruct patients to inform ophthalmologist of current or previous alpha1-blocker use when considering eye surgery. Initiation of tamsulosin therapy in patients with planned cataract surgery is not recommended.

• Orthostatic hypotension/syncope: May cause significant orthostatic hypotension and syncope, especially with first dose; anticipate a similar effect if therapy is interrupted for a few days, if dosage is rapidly increased, or if another antihypertensive drug (particularly vasodilators) or a PDE-5 inhibitor (eg, sildenafil, tadalafil, vardenafil) is introduced. "First-dose" orthostatic hypotension may occur 4-8 hours after dosing; may be dose-related. Patients should be cautioned about performing hazardous tasks when starting new therapy or adjusting dosage upward.

• Priapism: Priapism has been associated with tamsulosin use (rarely).

• Sulfonamide allergy: Rarely, patients with a sulfa allergy have also developed an allergic reaction to tamsulosin; avoid use when previous reaction has been severe.

Disease-related concerns:

• Diminished urinary flow: Carefully monitor patients with a large residual urinary volume or severely diminished urinary flow for obstructive uropathy; these patients may not be candidates for dutasteride combination therapy.

• Hepatic impairment: Use with caution in patients with hepatic impairment; use has not been studied.

• Prostate cancer: When compared to placebo, 5-alpha-reductase inhibitors (5-ARIs) have been shown to reduce the overall incidence of prostate cancer, although an increase in the incidence of high-grade prostate cancers has been observed; 5-ARIs are not approved in the U.S. or Canada for the prevention of prostate cancer.

• Renal impairment: Use caution in patients with ESRD (CrCl <10 mL/minute); use has not been studied.

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:

• Females: Not indicated for use in women.

Special handling:

• Hazardous agent: Use appropriate precautions for handling and disposal (NIOSH 2014 [group 3]).

• Women/pregnancy: Dutasteride can be absorbed through the skin; women should always use caution whenever handling. Pregnant women or women trying to conceive should not handle the product; if contact with a leaking capsule occurs, wash area immediately with soap and water; dutasteride may negatively impact fetal development.

Other warnings/precautions:

• Antihypertensive use: Not intended for use as an antihypertensive drug.

• Appropriate use: Other urological diseases, including prostate cancer, should be ruled out before initiating therapy.

• Blood donation: Avoid donating blood during or for 6 months following treatment cessation due to risk of administration to a pregnant female transfusion recipient.

• PSA monitoring: Dutasteride reduces prostate specific antigen (PSA) by ~50% within 3 to 6 months of use. Addition of tamsulosin did not effect changes in PSA; changes expected are similar to dutasteride monotherapy. If following serial PSAs, re-establish a new baseline ≥3 months after treatment initiation; monitor PSA periodically thereafter. If interpreting an isolated PSA value in a patient treated for ≥3 months, then double the PSA value for comparison to a normal PSA value in an untreated man. PSA increases while on dutasteride should be considered suspicious; obtain serial PSA measurements and evaluate (Andriole 2006). Patients on a 5-ARI with any increase in PSA levels, even if within normal limits, should be evaluated; may indicate presence of prostate cancer.

Monitoring Parameters

Objective and subjective signs of relief of benign prostatic hyperplasia, including improvement in urinary flow, reduction in symptoms of urgency, and relief of difficulty in micturition; for serial PSA monitoring, establish a new baseline PSA level after 3 months of therapy and monitor PSA periodically thereafter.

Pregnancy Risk Factor

X

Pregnancy Considerations

Use contraindicated in pregnancy. Not indicated for use in women. See individual agents.

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 rhinorrhea, sexual dysfunction, or decreased libido. Have patient report immediately to prescriber severe dizziness, passing out, lump in breast, breast pain or soreness, enlarged breasts, nipple discharge, depression, 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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