Finasteride

1 INDICATIONS & USAGE Finasteride tablets USP are indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY. Efficacy in bitemporal recession has not been established. Finasteride tablets USP are not indicated for use in women. • Finasteride tablets USP are 5α-reductase inhibitors indicated for the treatment of male pattern hair loss (androgenetic alopecia) in MEN ONLY ( 1 ). • Finasteride tablets USP are not indicated for use in women ( 1 , 4 , 5.1 ).

2 DOSAGE & ADMINISTRATION Finasteride tablets USP may be administered with or without meals. The recommended dose of finasteride tablets USP is one tablet (1 mg) taken once daily. In general, daily use for three months or more is necessary before benefit is observed. Continued use is recommended to sustain benefit, which should be re-evaluated periodically. Withdrawal of treatment leads to reversal of effect within 12 months. • Finasteride tablets USP may be administered with or without meals ( 2 ). • One tablet (1 mg) taken once daily ( 2 ). • In general, daily use for three months or more is necessary before benefit is observed ( 2 ).

6 ADVERSE REACTIONS The most common adverse reactions, reported in ≥1% of patients treated with finasteride tablets USP and greater than in patients treated with placebo are: decreased libido, erectile dysfunction and ejaculation disorder ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Hetero Labs Limited at 866-495-1995 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . See 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Clinical Studies for Finasteride Tablets USP 1 mg in the Treatment of Male Pattern Hair Loss In three controlled clinical trials for finasteride tablets USP of 12-month duration, 1.4% of patients taking finasteride tablets USP (n=945) were discontinued due to adverse experiences that were considered to be possibly, probably or definitely drug-related (1.6% for placebo; n=934). Clinical adverse experiences that were reported as possibly, probably or definitely drug-related in ≥1% of patients treated with finasteride tablets USP or placebo are presented in Table 1. TABLE 1 Drug-Related Adverse Experiences for Finasteride Tablets USP, 1 mg in Year 1 (%) MALE PATTERN HAIR LOSS Finasteride tablets USP N=945 Placebo N=934 Decreased Libido 1.8 1.3 Erectile Dysfunction 1.3 0.7 Ejaculation Disorder (Decreased Volume of Ejaculate) 1.2 (0.8) 0.7 (0.4) Discontinuation due to drug-related sexual adverse experiences 1.2 0.9 Integrated analysis of clinical adverse experiences showed that during treatment with finasteride tablets USP 36 (3.8%) of 945 men had reported one or more of these adverse experiences as compared to 20 (2.1%) of 934 men treated with placebo (p=0.04). Resolution occurred in men who discontinued therapy with finasteride tablets USP due to these side effects and in most of those who continued therapy. The incidence of each of the above adverse experiences decreased to ≤0.3% by the fifth year of treatment with finasteride tablets USP. In a study of finasteride 1 mg daily in healthy men, a median decrease in ejaculate volume of 0.3 mL (-11%) compared with 0.2 mL (-8%) for placebo was observed after 48 weeks of treatment. Two other studies showed that finasteride at 5 times the dosage of finasteride tablets USP (5 mg daily) produced significant median decreases of approximately 0.5 mL (-25%) compared to placebo in ejaculate volume, but this was reversible after discontinuation of treatment. In the clinical studies with finasteride tablets USP, the incidences for breast tenderness and enlargement, hypersensitivity reactions, and testicular pain in finasteride-treated patients were not different from those in patients treated with placebo. Controlled Clinical Trials and Long-Term Open Extension Studies for finasteride tablets USP, 5 mg and AVODART (dutasteride) in the Treatment of Benign Prostatic Hyperplasia In the finasteride tablets USP, 5 mg Long-Term Efficacy and Safety Study (PLESS), a 4-year controlled clinical study, 3040 patients between the ages of 45 and 78 with symptomatic BPH and an enlarged prostate were evaluated for safety over a period of 4 years (1524 on finasteride tablets USP, 5 mg/day and 1516 on placebo). 3.7% (57 patients) treated with finasteride tablets USP, 5 mg 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 2 presents the only clinical adverse reactions considered possibly, probably or definitely drug related by the investigator, for which the incidence on finasteride tablets USP, 5 mg was ≥1% and greater than placebo over the 4 years of the study. In years 2 to 4 of the study, there was no significant difference between treatment groups in the incidences of impotence, decreased libido and ejaculation disorder. TABLE 2 Drug-Related Adverse Experiences for finasteride tablets USP, 5 mg BENIGN PROSTATIC HYPERPLASIA Year 1 (%) Years 2, 3 and 4* (%) Finasteride, 5 mg Placebo Finasteride, 5 mg Placebo Impotence 8.1 3.7 5.1 5.1 Decreased Libido 6.4 3.4 2.6 2.6 Decreased Volume of Ejaculate 3.7 0.8 1.5 0.5 Ejaculation Disorder 0.8 0.1 0.2 0.1 Breast Enlargement 0.5 0.1 1.8 1.1 Breast Tenderness 0.4 0.1 0.7 0.3 Rash 0.5 0.2 0.5 0.1 *Combined Years 2 to 4 N = 1524 and 1516, finasteride vs placebo, respectively The adverse experience profiles in the 1-year, placebo-controlled, Phase III BPH studies and the 5-year open extensions with finasteride tablets USP, 5 mg and PLESS were similar. There is no evidence of increased sexual adverse experiences with increased duration of treatment with finasteride tablets USP, 5 mg. New reports of drug-related sexual adverse experiences decreased with duration of therapy. During the 4- to 6-year placebo- and comparator-controlled Medical Therapy of Prostatic Symptoms (MTOPS) study that enrolled 3047 men, there were 4 cases of breast cancer in men treated with finasteride tablets USP, 5 mg but no cases in men not treated with finasteride tablets USP, 5 mg. 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 tablets USP, 5 mg. During the 7-year placebo-controlled Prostate Cancer Prevention Trial (PCPT) that enrolled 18,882 men, there was 1 case of breast cancer in men treated with finasteride tablets USP, 5 mg, and 1 case of breast cancer in men treated with placebo. The relationship between long-term use of finasteride and male breast neoplasia is currently unknown. The PCPT trial was a 7-year randomized, double-blind, placebo-controlled trial that enrolled 18,882 healthy men ≥55 years of age with a normal digital rectal examination and a PSA ≤3 ng/mL. Men received either finasteride tablets USP, 5 mg or placebo daily. Patients were evaluated annually with PSA and digital rectal exams. Biopsies were performed for elevated PSA, an abnormal digital rectal exam, or the end of study. The incidence of Gleason score 8 to 10 prostate cancer was higher in men treated with finasteride (1.8%) than in those treated with placebo (1.1%). In a 4-year placebo-controlled clinical trial with another 5α-reductase inhibitor [AVODART (dutasteride)], similar results for Gleason score 8 to 10 prostate cancer were observed (1% dutasteride vs 0.5% placebo). The clinical significance of these findings with respect to use of finasteride tablets USP, 1 mg by men is unknown. No Clinical benefit has been demonstrated in patients with prostate cancer treated with finasteride tablets USP, 5 mg. Finasteride tablets USP, 5 mg are not approved to reduce the risk of developing prostate cancer. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of finasteride tablets USP. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: Hypersensitivity Reaction: hypersensitivity reactions such as rash, pruritus, urticaria, and angioedema (including swelling of the lips, tongue, throat, and face); Reproductive System: 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); testicular pain. [ See Adverse Reactions (6.1) .] Neoplasms: male breast cancer; Breast disorders : breast tenderness and enlargement; Nervous System/Psychiatric : depression

12.3 Pharmacokinetics Absorption In a study in 15 healthy young male subjects, the mean bioavailability of finasteride 1-mg tablets was 65% (range 26 to 170%), based on the ratio of area under the curve (AUC) relative to an intravenous (IV) reference dose. At steady state following dosing with 1 mg/day (n=12), maximum finasteride plasma concentration averaged 9.2 ng/mL (range, 4.9 to 13.7 ng/mL) and was reached 1 to 2 hours postdose ; AUC (0 to 24 hr) was 53 ng•hr/mL (range, 20 to 154 ng•hr/mL). Bioavailability of finasteride was not affected by food. Distribution Mean steady-state volume of distribution was 76 liters (range, 44 to 96 liters; n=15). Approximately 90% of circulating finasteride is bound to plasma proteins. There is a slow accumulation phase for finasteride after multiple dosing. Finasteride has been found to cross the blood-brain barrier. Semen levels have been measured in 35 men taking finasteride 1 mg/day for 6 weeks. In 60% (21 of 35) of the samples, finasteride levels were undetectable (<0.2 ng/mL). The mean finasteride level was 0.26 ng/mL and the highest level measured was 1.52 ng/mL. Using the highest semen level measured and assuming 100% absorption from a 5-mL ejaculate per day, human exposure through vaginal absorption would be up to 7.6 ng per day, which is 650-fold less than the dose of finasteride (5 mcg) that had no effect on circulating DHT levels in men. [ See Use in Specific Populations (8.1) .] Metabolism Finasteride is extensively metabolized in the liver, primarily via the cytochrome P450 3A4 enzyme subfamily. Two metabolites, the t-butyl side chain monohydroxylated and monocarboxylic acid metabolites, have been identified that possess no more than 20% of the 5α-reductase inhibitory activity of finasteride. Excretion Following intravenous infusion in healthy young subjects (n=15), mean plasma clearance of finasteride was 165 mL/min (range, 70 to 279 mL/min). Mean terminal half-life in plasma was 4.5 hours (range, 3.3 to 13.4 hours; n=12). Following an oral dose of 14 C-finasteride in man (n=6), a mean of 39% (range, 32 to 46%) of the dose was excreted in the urine in the form of metabolites; 57% (range, 51 to 64%) was excreted in the feces. Mean terminal half-life is approximately 5 to 6 hours in men 18 to 60 years of age and 8 hours in men more than 70 years of age. TABLE 3 Mean (SD) Pharmacokinetic Parameters in Healthy Men (ages 18 to 26) Mean (± SD)n=15 Bioavailability 65% (26-170%)* Clearance (mL/min) 165 (55) Volume of Distribution (L) 76 (14) *Range TABLE 4 Mean(SD) Noncompartmental Pharmacokinetic Parameters After Multiple Dosesof 1 mg/ day inHealthy Men (ages 19 to 42) AUC (ng· hr/mL) Mean (± SD) (n=12) 53 (33.8) Peak Concentration (ng/mL) 9.2 (2.6) Time to Peak (hours) 1.3 (0.5) Half-Life (hours)* 4.5 (1.6) *First-dose values; all other parameters are last-dose values Renal Impairment No dosage adjustment is necessary in patients with renal impairment. In patients with chronic renal impairment, with creatinine clearances ranging from 9 to 55 mL/min, AUC, maximum plasma concentration, half-life, and protein binding after a single dose of 14 C-finasteride were similar to those obtained in healthy volunteers. Urinary excretion of metabolites was decreased in patients with renal impairment. This decrease was associated with an increase in fecal excretion of metabolites. Plasma concentrations of metabolites were significantly higher in patients with renal impairment (based on a 60% increase in total radioactivity AUC). However, finasteride has been tolerated in men with normal renal function receiving up to 80 mg/day for 12 weeks where exposure of these patients to metabolites would presumably be much greater. Hepatic Impairment The effect of hepatic impairment on finasteride pharmacokinetics has not been studied. Caution should be used in the administration of finasteride tablets USP in patients with liver function abnormalities, as finasteride is metabolized extensively in the liver.