Proscar Side Effects

Generic name: finasteride

Generic Name: Finasteride

Please note - some side effects for Proscar may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Proscar - for the consumer

Proscar

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Proscar:

Decreased sexual desire or ability.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); breast enlargement, lumps, pain, or tenderness; nipple discharge; testicular pain.

For the professional

Proscar

Proscar is generally well tolerated; adverse reactions usually have been mild and transient.

4-Year Placebo-Controlled Study

In PLESS, 1524 patients treated with Proscar and 1516 patients treated with placebo were evaluated for safety over a period of 4 years. The most frequently reported adverse reactions were related to sexual function. 3.7% (57 patients) treated with Proscar and 2.1% (32 patients) treated with placebo discontinued therapy as a result of adverse reactions related to sexual function, which are the most frequently reported adverse reactions.

Table 4 presents the only clinical adverse reactions considered possibly, probably or definitely drug related by the investigator, for which the incidence on Proscar was ≥1% and greater than placebo over the 4 years of the study. In years 2-4 of the study, there was no significant difference between treatment groups in the incidences of impotence, decreased libido and ejaculation disorder.

Phase III Studies and 5-Year Open Extensions

The adverse experience profile in the 1-year, placebo-controlled, Phase III studies, the 5-year open extensions, and PLESS were similar.

Medical Therapy of Prostatic Symptoms (MTOPS) Study

The incidence rates of drug-related adverse experiences reported by ≥2% of patients in any treatment group in the MTOPS Study are listed in Table 5.

The individual adverse effects which occurred more frequently in the combination group compared to either drug alone were: asthenia, postural hypotension, peripheral edema, dizziness, decreased libido, rhinitis, abnormal ejaculation, impotence and abnormal sexual function. Of these, the incidence of abnormal ejaculation in patients receiving combination therapy was comparable to the sum of the incidences of this adverse experience reported for the two monotherapies.

Combination therapy with finasteride and doxazosin was associated with no new clinical adverse experience.

Four patients in MTOPS reported the adverse experience breast cancer. Three of these patients were on finasteride only and one was on combination therapy.

The MTOPS Study was not specifically designed to make statistical comparisons between groups for reported adverse experiences. In addition, direct comparisons of safety data between the MTOPS study and previous studies of the single agents may not be appropriate based upon differences in patient population, dosage or dose regimen, and other procedural and study design elements.

Long-Term Data

There is no evidence of increased adverse experiences with increased duration of treatment with Proscar. New reports of drug-related sexual adverse experiences decreased with duration of therapy.

During the 4- to 6-year placebo- and comparator-controlled MTOPS study that enrolled 3047 men, there were 4 cases of breast cancer in men treated with finasteride but no cases in men not treated with finasteride. During the 4-year, placebo-controlled PLESS study that enrolled 3040 men, there were 2 cases of breast cancer in placebo-treated men, but no cases were reported in men treated with finasteride. The relationship between long-term use of finasteride and male breast neoplasia is currently unknown.

In a 7-year placebo-controlled trial that enrolled 18,882 healthy men, 9060 had prostate needle biopsy data available for analysis. In the Proscar group, 280 (6.4%) men had prostate cancer with Gleason scores of 7-10 detected on needle biopsy vs. 237 (5.1%) men in the placebo group. Of the total cases of prostate cancer diagnosed in this study, approximately 98% were classified as intracapsular (stage T1 or T2). The clinical significance of these findings is unknown. This information from the literature (Thompson IM, Goodman PJ, Tangen CM, et al. The influence of finasteride on the development of prostate cancer. N Engl J Med 2003;349:213-22) is provided for consideration by physicians when Proscar is used as indicated. Proscar is not approved to reduce the risk of developing prostate cancer.

Post-Marketing Experience

The following additional adverse effects have been reported in post-marketing experience:

- hypersensitivity reactions, including pruritus, urticaria, and swelling of the lips and face

- testicular pain.

By body system

Genitourinary side effects

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.

Endocrine side effects

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

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

Cardiovascular side effects including postural hypotension (9.1%) and hypotension (1.2%) have been reported.

General side effects

General side effects including asthenia (5.3%), dizziness, headache, and abdominal pain have been reported.

Oncologic side effects

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.

Gastrointestinal side effects

Gastrointestinal side effects including nausea and flatulence have been reported.

Dermatologic side effects

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

Hypersensitivity side effects including pruritus, urticaria, and swelling of the lips and face have been reported.

Metabolic side effects

Metabolic side effects including peripheral edema (1.3%) have been reported.

Respiratory side effects

Respiratory side effects including rhinitis (1.0%) and dyspnea (0.7%) have been reported.

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