Dutasteride
Dutasteride and tamsulosin is a combination medication used to treat benign prostatic hyperplasia (BPH) in men. Dutasteride works by blocking the conversion of testosterone to dihydrotestosterone (DHT), which helps shrink the prostate over time, while tamsulosin relaxes smooth muscles in the prostate and bladder neck to improve urine flow and symptoms more quickly. This dual mechanism provides both symptomatic relief and reduction in prostate size for men with moderate to severe BPH.
A combination medication for BPH that combines a 5-alpha-reductase inhibitor with an alpha-blocker to reduce prostate size and improve urinary symptoms.
Key facts at a glance
- ATC
- G04CB02
- RxNorm
- 228790
- Generic
- Dutasteride
- Class
- atc-g04
- Brands
- Avodart, Jalyn
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- capsule
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treatment of moderate to severe symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate. Helps improve urinary flow, reduce prostate size, decrease the risk of acute urinary retention, and reduce the need for surgery.
Dutasteride inhibits type I and type II 5-alpha-reductase enzymes, blocking conversion of testosterone to dihydrotestosterone (DHT), which reduces prostate volume. Tamsulosin selectively blocks alpha-1A-adrenergic receptors in the prostate, bladder neck, and prostatic urethra, relaxing smooth muscle and improving urine flow. The combination provides both rapid symptom relief (tamsulosin) and long-term prostate shrinkage (dutasteride).
Not indicated for use in women, children, or adolescents. May take 3-6 months to see full benefits from dutasteride component. Men should not donate blood while taking this medication (due to dutasteride). Common side effects include erectile dysfunction, decreased libido, ejaculation disorders, and dizziness. PSA levels are reduced by dutasteride, which should be considered when screening for prostate cancer. Contraindicated in patients with severe hepatic impairment and those with known hypersensitivity to 5-alpha-reductase inhibitors or alpha-blockers.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy