Version July 2025
Benign prostatic hyperplasia: Note: Reserve use for patients with a significantly enlarged prostate (prostate volume >30 mL, a prostate specific antigen >1.5 ng/mL, or palpable prostate enlargement on digital rectal exam) (Ref).
Oral: One capsule (dutasteride 0.5 mg/tamsulosin 0.4 mg) 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.
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).
There are no dosage adjustments provided in the manufacturer's labeling. See individual agents.
Refer to adult dosing.
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)
Clinically significant hypersensitivity (eg, serious skin reactions, angioedema, urticaria, pruritus, respiratory symptoms) to dutasteride, tamsulosin, other 5-alpha-reductase inhibitors, or any component of the formulation; pregnancy.
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.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Capsule, Oral:
Jalyn: dutasteride 0.5 mg and tamsulosin hydrochloride 0.4 mg [contains carrageenan, fd&c yellow #6 (sunset yellow)]
Jalyn: Dutasteride 0.5 mg and tamsulosin hydrochloride 0.4 mg [DSC] [contains carrageenan, fd&c yellow #6 (sunset yellow), gelatin (bovine)]
Generic: dutasteride 0.5 mg and tamsulosin hydrochloride 0.4 mg
Yes
Capsules (Dutasteride-Tamsulosin HCl Oral)
0.5-0.4 mg (per each): $6.05
Capsules (Jalyn Oral)
0.5-0.4 mg (per each): $78.00
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
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)]
Oral: 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.
Dutasteride is a hazardous agent (NIOSH 2024 [table 2]).
Use appropriate precautions for receiving, handling, storage, preparation, dispensing, transporting, administration, and disposal. Follow NIOSH and USP 800 recommendations and institution-specific policies/procedures for appropriate containment strategy (NIOSH 2023; NIOSH 2024; USP-NF 2020).
Note: Facilities may perform risk assessment of some hazardous drugs to determine if appropriate for alternative handling and containment strategies (USP-NF 2020). Refer to institution-specific handling policies/procedures.
Benign prostatic hyperplasia: Treatment of symptomatic benign prostatic hyperplasia in patients with an enlarged prostate.
Limitations of use: Dutasteride-containing products are not approved for the prevention of prostate cancer.
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drugs (contraindicated in pregnancy) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Community/Ambulatory Care Settings).
Refer to individual components.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Ajmaline: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Alpha-/Beta-Agonists: Alpha1-Blockers may decrease therapeutic effects of Alpha-/Beta-Agonists. Risk C: Monitor
Alpha1-Blockers: May increase antihypertensive effects of Alpha1-Blockers. Risk X: Avoid
Amifostine: Blood Pressure Lowering Agents may increase hypotensive effects 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. Risk D: Consider Therapy Modification
Amisulpride (Oral): May increase hypotensive effects of Hypotension-Associated Agents. Risk C: Monitor
Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may increase hypotensive effects of Antipsychotic Agents (Second Generation [Atypical]). Risk C: Monitor
Arginine: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Artemether and Lumefantrine: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Barbiturates: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Benperidol: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Blood Pressure Lowering Agents: May increase hypotensive effects of Hypotension-Associated Agents. Risk C: Monitor
Brimonidine (Topical): May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Bromperidol: May decrease hypotensive effects of Blood Pressure Lowering Agents. Blood Pressure Lowering Agents may increase hypotensive effects of Bromperidol. Risk X: Avoid
Cimetidine: May increase serum concentration of Tamsulosin. Risk C: Monitor
Clofazimine: May increase serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Risk C: Monitor
CYP2D6 Inhibitors (Moderate): May increase serum concentration of Tamsulosin. Risk C: Monitor
CYP2D6 Inhibitors (Strong): May increase serum concentration of Tamsulosin. Risk C: Monitor
CYP3A4 Inhibitors (Moderate): May increase serum concentration of Tamsulosin. Risk C: Monitor
CYP3A4 Inhibitors (Strong): May increase serum concentration of Tamsulosin. Risk X: Avoid
Dapoxetine: May increase orthostatic hypotensive effects of Alpha1-Blockers. Risk C: Monitor
Diazoxide: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
DULoxetine: Blood Pressure Lowering Agents may increase hypotensive effects of DULoxetine. Risk C: Monitor
Fusidic Acid (Systemic): May increase serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Management: Consider avoiding this combination if possible. If required, monitor patients closely for increased adverse effects of the CYP3A4 substrate. Risk D: Consider Therapy Modification
Grapefruit Juice: May increase serum concentration of Tamsulosin. Risk C: Monitor
Herbal Products with Blood Pressure Lowering Effects: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Hypotension-Associated Agents: Blood Pressure Lowering Agents may increase hypotensive effects of Hypotension-Associated Agents. Risk C: Monitor
Iloperidone: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Levodopa-Foslevodopa: Blood Pressure Lowering Agents may increase hypotensive effects of Levodopa-Foslevodopa. Risk C: Monitor
Lormetazepam: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Mavorixafor: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk X: Avoid
Metergoline: May decrease antihypertensive effects of Blood Pressure Lowering Agents. Blood Pressure Lowering Agents may increase orthostatic hypotensive effects of Metergoline. Risk C: Monitor
Molsidomine: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Nicorandil: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Nitroprusside: Blood Pressure Lowering Agents may increase hypotensive effects of Nitroprusside. Risk C: Monitor
Obinutuzumab: May increase hypotensive effects 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. Risk D: Consider Therapy Modification
Peginterferon Alfa-2b: May decrease serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Pentoxifylline: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Phenylephrine (Systemic): Alpha1-Blockers may decrease vasoconstricting effects of Phenylephrine (Systemic). Risk C: Monitor
Pholcodine: Blood Pressure Lowering Agents may increase hypotensive effects of Pholcodine. Risk C: Monitor
Phosphodiesterase 5 Inhibitors: Alpha1-Blockers (Uroselective) may increase hypotensive effects of Phosphodiesterase 5 Inhibitors. Risk C: Monitor
Prostacyclin Analogues: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Quinagolide: May increase hypotensive effects of Blood Pressure Lowering Agents. Risk C: Monitor
Rilmenidine: Alpha1-Blockers may increase hypotensive effects of Rilmenidine. Risk C: Monitor
See individual agents.
Persons who may become pregnant should not handle the product; if contact with a leaking capsule occurs, wash area immediately with soap and water.
Dutasteride can be detected in semen. Refer to the individual monographs for additional information.
Dutasteride may negatively impact the development of a male fetus. Pregnant patients should not handle the product; if contact with a leaking capsule occurs, wash area immediately with soap and water. Use is contraindicated during pregnancy.
Refer to individual monographs for additional information.
It is not known if dutasteride or tamsulosin are present in breast milk.
International Prostate Symptom Score (baseline and 3 to 12 months after treatment initiation); urinalysis (baseline); BP; for serial prostate-specific antigen (PSA) monitoring, establish a new baseline PSA level after 3 months of therapy and monitor PSA periodically thereafter; objective and subjective signs of relief of benign prostatic hyperplasia and lower urinary tract symptoms (AUA [Lerner 2021]; McVary 2021; manufacturer's labeling).
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.
See individual agents.
