Finasteride Side Effects
Some side effects of finasteride may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
Applies to finasteride: oral tablet
Get emergency medical help if you have any of these signs of an allergic reaction while taking finasteride: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you notice any breast lumps, pain, nipple discharge, or other breast changes. These may be signs of male breast cancer.
Less serious side effects of finasteride may include:
impotence, loss of interest in sex, or trouble having an orgasm;
swelling in your hands or feet;
swelling or tenderness in your breasts;
feeling like you might pass out;
runny nose; or
The sexual side effects of finasteride (decreased libido, trouble having an erection, ejaculation problems) may continue after you stop taking this medication. Talk to your doctor if you have concerns about these side effects.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
For Healthcare Professionals
Applies to finasteride: oral tablet
Two hundred fourteen reports of gynecomastia in men taking finasteride in the United States were received by the FDA between June 1992 and February 1995. Among those reported, fifty eight percent were taking additional medications that have been associated with gynecomastia. Sixty nine of 86 patients who discontinued finasteride treatment had partial or complete remission.
New reports of drug-related sexual adverse experiences have been reported to decrease with duration of therapy.
Genitourinary side effects have included impotence (1.1% to 18.5%), abnormal ejaculation (7.2%), decreased ejaculatory volume (0.9% to 2.8%), abnormal sexual function (2.5%), gynecomastia (2.2%), erectile dysfunction (1.3%), ejaculation disorder (1.2%), and testicular pain. The manufacturer has reported that in controlled clinical trials, 1.2% of patients on finasteride tablets discontinued therapy because of a drug-related sexual adverse experience. Postmarketing reports have included sexual dysfunction that continued after discontinuation of treatment, including erectile dysfunction, libido disorders, ejaculation disorders, and orgasm disorders; male infertility and/or poor seminal quality (normalization or improvement of seminal quality has been reported after discontinuation of finasteride); and testicular pain.
Endocrine side effects have included reductions in prostate specific antigen (PSA) levels of approximately 50%.
Finasteride may cause a decrease in PSA levels in patients with benign prostatic hyperplasia as well as in patients with prostate cancer. In one study, mean PSA reductions of 50% were noted, regardless of baseline levels. There was no indication that PSA levels were further suppressed in patients with prostate cancer.
PSA levels are commonly used in the screening process for prostate cancer. Patients who develop sustained increases in PSA while on finasteride therapy should be carefully evaluated for medical causes as well as noncompliance.
Nervous system side effects including decreased libido (1.6% to 10.0%), dizziness (7.4%), and somnolence (1.7%) have been reported.
Cardiovascular side effects including postural hypotension (9.1%) and hypotension (1.2%) have been reported.
General side effects including asthenia (5.3%), dizziness, headache, and abdominal pain have been reported.
Oncologic side effects have included a prevention or delay in the appearance of prostate cancer. However, finasteride has also been linked to an increased risk of high grade prostate cancer. Postmarketing experience has included rare cases of male breast cancer.
Gastrointestinal side effects including nausea and flatulence have been reported.
A 58 year old man presented with an itchy, lumpy rash on upper and lower extremities following two weeks of finasteride treatment for prostatism. The patient had no known allergies and was taking no other medications prior to the episode. The finasteride was discontinued and dapsone was initiated. The rash resolved two weeks after finasteride therapy was stopped.
Dermatologic side effects including rash have been rare. At least one case of cutaneous leukocytoclastic vasculitis has been associated with finasteride therapy. A case of solitary fixed drug eruption has also been reported.
Hypersensitivity side effects including pruritus, urticaria, and swelling of the lips and face have been reported.
Metabolic side effects including peripheral edema (1.3%) have been reported.
Respiratory side effects including rhinitis (1.0%) and dyspnea (0.7%) have been reported.
Psychiatric side effects have included depression.
More finasteride resources
- finasteride MedFacts Consumer Leaflet (Wolters Kluwer)
- finasteride Advanced Consumer (Micromedex) - Includes Dosage Information
- Finasteride Prescribing Information (FDA)
- Finasteride Professional Patient Advice (Wolters Kluwer)
- Finasteride Monograph (AHFS DI)
- Propecia Prescribing Information (FDA)
- Propecia MedFacts Consumer Leaflet (Wolters Kluwer)
- Propecia Consumer Overview
- Proscar Prescribing Information (FDA)
- Proscar Consumer Overview
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