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Last reviewed on RxList: 5/3/2017
Duagen Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 4/28/2016

Duagen (dutasteride) is a 5-alpha reductase inhibitor used to treat symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate gland. Duagen may be available in generic form. Common side effects of Duagen include:

  • impotence
  • decreased sex drive (libido)
  • difficulty ejaculating, and
  • enlargement of breast tissue

The recommended dose of Duagen is 1 capsule (0.5 mg) taken orally once a day. Duagen may interact with conivaptan, imatinib, isoniazid, antibiotics, antifungals, antidepressants, heart or blood pressure medications, or HIV/AIDS medicines. Tell your doctor all medications and supplements you use. Duagen is not intended for use in women, therefore it is unlikely to be used during pregnancy or while breastfeeding; consult your doctor.

Our Duagen (dutasteride) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Duagen Professional Information


Adverse reactions were generally mild and transient. The most common adverse events leading to withdrawal in both treatment groups were associated with the reproductive system.

The data described below reflect exposure to Duagen (dutasteride) in 2166 male subjects, including 1772 exposed for one year. Over 4300 male subjects with BPH were randomly assigned to receive placebo or 0.5-mg daily doses of Duagen (dutasteride) in three identical, placebo-controlled Phase in treatment studies. The population was aged 47 to 94 years (mean age 66 years) and greater than 90% Caucasian. A total of 267 subjects (6% of each treatment group) were withdrawn from the studies due to adverse experiences, usually associated with the reproductive system. Withdrawals due to adverse events considered by the investigator to have a reasonable possibility of being caused by the study medication occurred in 3% of the subjects receiving Duagen (dutasteride) and in 2% of the subjects receiving placebo. Table 1 summarizes clinical adverse reactions that were reported by the investigator as drug-related in at least 1% of subjects receiving Duagen (dutasteride) and at a higher incidence than subjects receiving placebo.

Table 1: Drug-related Adverse Events* Reported in >1% Subjects and More Frequently in the

Duagen (dutasteride) Group than the Placebo Group Pivotal Studies Pooled

Placebo (N = 2158)

Duagen (dutasteride)

(N = 2l66)

59 (3%)


Decreased libido

40 (2%)

74 (3%)

Ejaculation disorders


40 (2%)




* A drug-related adverse event is one considered by the investigator to have a reasonable possibility of being caused by the study medication. In assessing causality, investigators were asked to select from one of two options: reasonably related to study medication or unrelated to study medication.

Includes breast tenderness and breast enlargement

Long-Term Treatment: The incidence of sexual adverse events considered by the investigator to have a reasonable possibility of being drug-related decreased with duration of treatment; after the first 6 months of treatment the incidence of onset of impotence, decreased libido, ejaculation disorders or gynecomastia was <1% for subjects receiving either Duagen (dutasteride) or placebo.

The adverse event profile for 677 subjects who were maintained on Duagen (dutasteride) 0.5 mg/day for 24 months in one pivotal study was consistent with that observed after 12 months of treatment in the three studies combined. The incidence of onset of drug-related events was lower during the second year of treatment compared with the first year of treatment, with the exception of gynecomastia (onset in 1 % during first year and 2% during second year).

Read the entire FDA prescribing information for Duagen (Dutasteride)

Related Resources for Duagen

© Duagen Patient Information is supplied by Cerner Multum, Inc. and Duagen Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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