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Dutasteride and Tamsulosin

Medically reviewed by Drugs.com. Last updated on Nov 5, 2020.

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 [contains fd&c yellow #6 (sunset yellow)]

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 alpha1A subtype.

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

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Dosing: Geriatric

Refer to adult dosing.

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.

Storage

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

Drug Interactions

Abametapir: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination

Ajmaline: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

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 used at chemotherapy doses, hold blood pressure lowering medications for 24 hours before amifostine administration. If blood pressure lowering therapy cannot be held, do not administer amifostine. Use caution with radiotherapy doses of amifostine. Consider therapy modification

Amisulpride (Oral): May enhance the hypotensive effect of Hypotension-Associated Agents. Monitor therapy

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 (High risk with Inhibitors). Monitor therapy

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

Benperidol: 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. Monitor therapy

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

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

Bromperidol: Blood Pressure Lowering Agents may enhance the hypotensive effect of Bromperidol. Bromperidol may diminish the hypotensive effect of Blood Pressure Lowering Agents. Avoid combination

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

Clofazimine: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Conivaptan: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination

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

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

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

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates (High risk with Inducers). 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 increase the serum concentration of Tamsulosin. Monitor therapy

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

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Seek alternatives to concomitant therapy when possible. If concomitant therapy cannot be avoided, monitor for reduced clinical effects of the CYP3A4 substrate. Consider therapy modification

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

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). 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

Duvelisib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). 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

Erdafitinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Erdafitinib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Fosaprepitant: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Fosnetupitant: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

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

Ivosidenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Larotrectinib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

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

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

Lumefantrine: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Mitotane: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). 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 (High risk with Inhibitors). 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 (High risk with Inhibitors). Monitor therapy

Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

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

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

Phosphodiesterase 5 Inhibitors: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Phosphodiesterase 5 Inhibitors: Alpha1-Blockers (Uroselective) may enhance the hypotensive effect of Phosphodiesterase 5 Inhibitors. Monitor therapy

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

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

Sarilumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Simeprevir: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy

Stiripentol: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). 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 (High risk with Inducers). 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

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

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%, postmarketing, and/or case reports: Malignant neoplasm of prostate (high-grade)

Warnings/Precautions

Concerns related to adverse effects:

• Floppy iris syndrome: Intraoperative floppy iris syndrome (IFIS) is characterized by a combination of flaccid iris that billows with intraoperative currents, progressive intraoperative miosis despite dilation, and potential iris prolapse. IFIS has been observed in cataract surgery patients who were on or were previously treated with alpha-1 blockers, particularly with tamsulosin use (Abdel-Aziz 2009); in some cases, patients had discontinued the alpha-1 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 alpha-1 blocker use when considering eye surgery. Initiation of tamsulosin therapy in patients with planned cataract or glaucoma 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.

Special populations:

• Females: Not indicated for use in women.

Special handling:

• Women/pregnancy: Dutasteride can be absorbed through the skin; women should always use caution whenever handling.

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.

Reproductive Considerations

Women trying to conceive should not handle the product; if contact with a leaking capsule occurs, wash area immediately with soap and water. Use is contraindicated in females of reproductive potential.

Dutasteride can be detected in semen; the effect on male fertility is unknown. Refer to the dutasteride monograph for additional information.

Pregnancy Risk Factor

X

Pregnancy Considerations

Pregnant women 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. Use is contraindicated during pregnancy. Refer to individual monographs for additional information.

Patient Education

What is this drug used for?

• In men, it is used to treat the signs of an enlarged prostate.

• It may be given to you for other reasons. Talk with the doctor.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Runny nose

• Sexual dysfunction

• Decreased sex drive

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Dizziness

• Passing out

• Lump in breast

• Breast pain or soreness

• Enlarged breasts

• Nipple discharge

• Depression

• Erection that lasts more than 4 hours

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

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