Finasteride, a synthetic 4-azasteroid compound, is a specific inhibitor of steroid Type II 5α-reductase, an intracellular enzyme that converts the androgen testosterone into 5α-dihydrotestosterone (DHT).
Finasteride is 4-azaandrost-1-ene-17-carboxamide, N-(1,1-dimethylethyl)-3-oxo-,(5α,17ß)-. The empirical formula of finasteride is C23H36N2O2 and its molecular weight is 372.55. Its structural formula is:
Finasteride is a white crystalline powder with a melting point near 250°C. It is freely soluble in chloroform and in lower alcohol solvents, but is practically insoluble in water.
Finasteride 5 mg tablets for oral administration are film-coated tablets that contain 5 mg of finasteride and the following inactive ingredients: hydrous lactose, microcrystalline cellulose, pregelatinized starch, sodium starch glycolate, hydroxypropyl cellulose LF, hydroxypropyl methylcellulose, titanium dioxide, magnesium stearate, talc, docusate sodium, FD&C Blue 2 aluminum lake and yellow iron oxide.
The development and enlargement of the prostate gland is dependent on the potent androgen, 5α-dihydrotestosterone (DHT). Type II 5α-reductase metabolizes testosterone to DHT in the prostate gland, liver and skin. DHT induces androgenic effects by binding to androgen receptors in the cell nuclei of these organs.
Finasteride is a competitive and specific inhibitor of Type II 5α-reductase with which it slowly forms a stable enzyme complex. Turnover from this complex is extremely slow (t½~ 30 days). This has been demonstrated both in vivo and in vitro. Finasteride has no affinity for the androgen receptor. In man, the 5α-reduced steroid metabolites in blood and urine are decreased after administration of finasteride.
In man, a single 5-mg oral dose of finasteride produces a rapid reduction in serum DHT concentration, with the maximum effect observed 8 hours after the first dose. The suppression of DHT is maintained throughout the 24-hour dosing interval and with continued treatment. Daily dosing of finasteride at 5 mg/day for up to 4 years has been shown to reduce the serum DHT concentration by approximately 70%. The median circulating level of testosterone increased by approximately 10-20% but remained within the physiologic range.
Adult males with genetically inherited Type II 5α-reductase deficiency also have decreased levels of DHT. Except for the associated urogenital defects present at birth, no other clinical abnormalities related to Type II 5α-reductase deficiency have been observed in these individuals. These individuals have a small prostate gland throughout life and do not develop BPH.
In patients with BPH treated with finasteride (1-100 mg/day) for 7-10 days prior to prostatectomy, an approximate 80% lower DHT span was measured in prostatic tissue removed at surgery, compared to placebo; testosterone tissue concentration was increased up to 10 times over pretreatment levels, relative to placebo. Intraprostatic span of prostate-specific antigen (PSA) was also decreased.
In healthy male volunteers treated with finasteride 5mg tablets for 14 days, discontinuation of therapy resulted in a return of DHT levels to pretreatment levels in approximately 2 weeks. In patients treated for three months, prostate volume, which declined by approximately 20%, returned to close to baseline value after approximately three months of discontinuation of therapy.
Finasteride 5 mg/day was initially evaluated in patients with symptoms of BPH and enlarged prostates by digital rectal examination in two 1-year, placebo-controlled, randomized, double-blind studies and their 5-year open extensions.
Finasteride 5 mg tablets were further evaluated in the PROSCAR (Finasteride) Long-Term Efficacy and Safety Study (PLESS), a double-blind, randomized, placebo-controlled, 4-year, multicenter study. 3040 patients between the ages of 45 and 78, with moderate to severe symptoms of BPH and an enlarged prostate upon digital rectal examination, were randomized into the study (1524 to finasteride, 1516 to placebo) and 3016 patients were evaluable for efficacy. 1883 patients completed the 4-year study (1000 in the finasteride group, 883 in the placebo group).
Symptoms were quantified using a score similar to the American Urological Association Symptom Score, which evaluated both obstructive symptoms (impairment of size and force of stream, sensation of incomplete bladder emptying, delayed or interrupted urination) and irritative symptoms (nocturia, daytime frequency, need to strain or push the flow of urine) by rating on a 0 to 5 scale for six symptoms and a 0 to 4 scale for one symptom, for a total possible score of 34.
Patients in PLESS had moderate to severe symptoms at baseline (mean of approximately 15 points on a 0-34 point scale). Patients randomized to finasteride 5 mg tablets who remained on therapy for 4 years had a mean (± 1 SD) decrease in symptom score of 3.3 (± 5.8) points compared with 1.3 (± 5.6) points in the placebo group. (See Figure 1.) A statistically significant improvement in symptom score was evident at 1 year in patients treated with finasteride 5 mg tablets vs placebo (–2.3 vs –1.6), and this improvement continued through Year 4.
Results seen in earlier studies were comparable to those seen in PLESS. Although an early improvement in urinary symptoms was seen in some patients, a therapeutic trial of at least 6 months was generally necessary to assess whether a beneficial response in symptom relief had been achieved. The improvement in BPH symptoms was seen during the first year and maintained throughout an additional 5 years of open extension studies.
In PLESS, efficacy was also assessed by evaluating treatment failures. Treatment failure was prospectively defined as BPH-related urological events or clinical deterioration, lack of improvement and/or the need for alternative therapy. BPH-related urological events were defined as urological surgical intervention and acute urinary retention requiring catheterization. Complete event information was available for 92% of the patients. The following table (Table 1) summarizes the results.
|95% CI||P |
|All Treatment Failures||37.1||26.2||0.68||(0.57 to 0.79)||<0.001|
|Surgical Interventions for BPH||10.1||4.6||0.45||(0.32 to 0.63)||<0.001|
|Acute Urinary Retention Requiring Catheterization||6.6||2.8||0.43||(0.28 to 0.66)||<0.001|
|Two consecutive symptom scores ≥20||9.2||6.7|
|Discontinuation due to worsening of BPH, lack of improvement, or to receive other medical treatment||21.8||13.3|
Compared with placebo, finasteride 5 mg tablets was associated with a significantly lower risk for acute urinary retention or the need for BPH-related surgery [13.2% for placebo vs 6.6% for finasteride 5 mg tablets; 51% reduction in risk, 95% CI: (34 to 63%)]. Compared with placebo, finasteride 5 mg tablets were associated with a significantly lower risk for surgery [10.1% for placebo vs 4.6% for finasteride 5 mg tablets; 55% reduction in risk, 95% CI: (37 to 68%)] and with a significantly lower risk of acute urinary retention [6.6% for placebo vs 2.8% for finasteride 5 mg tablets; 57% reduction in risk, 95% CI: (34 to 72%)]; see Figures 2 and 3.
In PLESS, prostate volume was assessed yearly by magnetic resonance imaging (MRI) in a subset of patients. In patients treated with finasteride 5 mg tablets who remained on therapy, prostate volume was reduced compared with both baseline and placebo throughout the 4-year study. Finasteride 5 mg tablets decreased prostate volume by 17.9% (from 55.9 cc at baseline to 45.8 cc at 4 years) compared with an increase of 14.1% (from 51.3 cc to 58.5 cc) in the placebo group (p<0.001). (See Figure 4.)
Results seen in earlier studies were comparable to those seen in PLESS. Mean prostate volume at baseline ranged between 40-50 cc. The reduction in prostate volume was seen during the first year and maintained throughout an additional five years of open extension studies.
The Medical Therapy of Prostatic Symptoms (MTOPS) Trial was a double-blind, randomized, placebo-controlled, multicenter, 4- to 6-year study (average 5 years) in 3047 men with symptomatic BPH, who were randomized to receive finasteride 5 mg/day (n=768), doxazosin 4 or 8 mg/day (n=756), the combination of finasteride 5 mg/day and doxazosin 4 or 8 mg/day (n=786), or placebo (n=737). All participants underwent weekly titration of doxazosin (or its placebo) from 1 to 2 to 4 to 8 mg/day. Only those who tolerated the 4 or 8 mg dose level were kept on doxazosin (or its placebo) in the study. The participant’s final tolerated dose (either 4 mg or 8 mg) was administered beginning at end-Week 4. The final doxazosin dose was administered once per day, at bedtime.
The mean patient age at randomization was 62.6 years (±7.3 years). Patients were Caucasian (82%), African American (9%), Hispanic (7%), Asian (1%) or Native American (<1%). The mean duration of BPH symptoms was 4.7 years (±4.6 years). Patients had moderate to severe BPH symptoms at baseline with a mean AUA symptom score of approximately 17 out of 35 points. Mean maximum urinary flow rate was 10.5 mL/sec (±2.6 mL/sec). The mean prostate volume as measured by transrectal ultrasound was 36.3 mL (±20.1 mL). Prostate volume was ≤20 mL in 16% of patients, ≥50 mL in 18% of patients and between 21 and 49 mL in 66% of patients.
The primary endpoint was a composite measure of the first occurrence of any of the following five outcomes: a ≥4 point confirmed increase from baseline in symptom score, acute urinary retention, BPH-related renal insufficiency (creatinine rise), recurrent urinary tract infections or urosepsis, or incontinence. Compared to placebo, treatment with finasteride 5 mg tablets, doxazosin, or combination therapy resulted in a reduction in the risk of experiencing one of these five outcome events by 34% (p=0.002), 39% (p<0.001), and 67% (p<0.001), respectively. Combination therapy resulted in a significant reduction in the risk of the primary endpoint compared to treatment with finasteride 5 mg tablets alone (49%; p≤0.001) or doxazosin alone (46%; p≤0.001). (See Table 2.)
|Event||N (%)||N (%)||N (%)||N (%)||N (%)|
|AUA 4-point rise||100 (13.6)||59 (7.8)||74 (9.6)||41 (5.2)||274 (9.0)|
|Acute urinary retention||18 (2.4)||13 (1.7)||6 (0.8)||4 (0.5)||41 (1.3)|
|Incontinence||8 (1.1)||11 (1.5)||9 (1.2)||3 (0.4)||31 (1.0)|
|Recurrent UTI/urosepsis||2 (0.3)||2 (0.3)||0 (0.0)||1 (0.1)||5 (0.2)|
|Creatinine rise||0 (0.0)||0 (0.0)||0 (0.0)||0 (0.0)||0 (0.0)|
|Total Events||128 (17.4)||85 (11.2)||89 (11.6)||49 (6.2)||351 (11.5)|
The majority of the events (274 out of 351; 78%) was a confirmed≥4 point increase in symptom score, referred to as symptom score progression. The risk of symptom score progression was reduced by 30% (p=0.016), 46% (p<0.001), and 64% (p<0.001) in patients treated with finasteride 5 mg tablets, doxazosin, or the combination, respectively, compared to patients treated with placebo (see Figure 5). Combination therapy significantly reduced the risk of symptom score progression compared to the effect of finasteride 5 mg tablets alone (p<0.001) and compared to doxazosin alone (p=0.037).
Treatment with finasteride 5 mg tablets, doxazosin or the combination of finasteride 5 mg tablets with doxazosin, reduced the mean symptom score from baseline at year 4. Table 3 provides the mean change from baseline for AUA symptom score by treatment group for patients who remained on therapy for four years.
|Baseline Mean (SD)||16.8 (6.0)||17.0 (5.9)||17.1 (6.0)||16.8 (5.8)|
AUA Symptom Score (SD)
Placebo (95% CI)
Doxazosin alone (95% CI)
Finasteride alone (95% CI)
The results of MTOPS are consistent with the findings of the 4-year, placebo-controlled study PLESS (see CLINICAL PHARMACOLOGY, Clinical Studies) in that treatment with finasteride 5 mg tablets reduces the risk of acute urinary retention and the need for BPH-related surgery. In MTOPS, the risk of developing acute urinary retention was reduced by 67% in patients treated with finasteride 5 mg tablets compared to patients treated with placebo (0.8% for finasteride 5 mg tablets and 2.4% for placebo). Also, the risk of requiring BPH-related invasive therapy was reduced by 64% in patients treated with finasteride 5 mg tablets compared to patients treated with placebo (2.0% for finasteride 5 mg tablets and 5.4% for placebo).
Finasteride 5 mg Tablets, USP are indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to:
Finasteride 5 mg Tablets, USP administered in combination with the alpha-blocker doxazosin is indicated to reduce the risk of symptomatic progression of BPH (a confirmed ≥4 point increase in AUA symptom score).
Finasteride 5 mg tablets are contraindicated in the following:
Hypersensitivity to any component of this medication.
Pregnancy. Finasteride use is contraindicated in women when they are or may potentially be pregnant. Because of the ability of Type II 5α-reductase inhibitors to inhibit the conversion of testosterone to DHT, finasteride may cause abnormalities of the external genitalia of a male fetus of a pregnant woman who receives finasteride. If this drug is used during pregnancy, or if pregnancy occurs while taking this drug, the pregnant woman should be apprised of the potential hazard to the male fetus. (See also WARNINGS, EXPOSURE OF WOMEN — RISK TO MALE FETUS and PRECAUTIONS, Information for Patients and Pregnancy.) In female rats, low doses of finasteride administered during pregnancy have produced abnormalities of the external genitalia in male offspring.
Finasteride 5 mg tablets is not indicated for use in pediatric patients (see PRECAUTIONS, Pediatric Use) or women (see also WARNINGS, EXPOSURE OF WOMEN — RISK TO MALE FETUS; PRECAUTIONS, Information for Patients and Pregnancy; and HOW SUPPLIED).
Women should not handle crushed or broken finasteride 5 mg tablets when they are pregnant or may potentially be pregnant because of the possibility of absorption of finasteride and the subsequent potential risk to a male fetus. Finasteride 5 mg tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed. (See CONTRAINDICATIONS; PRECAUTIONS, Information for Patients and Pregnancy; and HOW SUPPLIED.)
Prior to initiating therapy with finasteride 5 mg tablets, appropriate evaluation should be performed to identify other conditions such as infection, prostate cancer, stricture disease, hypotonic bladder or other neurogenic disorders that might mimic BPH.
Patients with large residual urinary volume and/or severely diminished urinary flow should be carefully monitored for obstructive uropathy. These patients may not be candidates for finasteride therapy.
Caution should be used in the administration of finasteride 5 mg tablets in those patients with liver function abnormalities, as finasteride is metabolized extensively in the liver.
No clinical benefit has been demonstrated in patients with prostate cancer treated with finasteride 5 mg tablets. Patients with BPH and elevated PSA were monitored in controlled clinical studies with serial PSAs and prostate biopsies. In these BPH studies, finasteride 5 mg tablets did not appear to alter the rate of prostate cancer detection, and the overall incidence of prostate cancer was not significantly different in patients treated with finasteride 5 mg tablets or placebo.
Finasteride 5 mg tablets cause a decrease in serum PSA levels by approximately 50% in patients with BPH, even in the presence of prostate cancer. This decrease is predictable over the entire range of PSA values, although it may vary in individual patients. Analysis of PSA data from over 3000 patients in PLESS confirmed that in typical patients treated with finasteride 5 mg tablets for six months or more, PSA values should be doubled for comparison with normal ranges in untreated men. This adjustment preserves the sensitivity and specificity of the PSA assay and maintains its ability to detect prostate cancer.
Any sustained increases in PSA levels while on finasteride 5 mg tablets should be carefully evaluated, including consideration of non-compliance to therapy with finasteride 5 mg tablets.
Percent free PSA (free to total PSA ratio) is not significantly decreased by finasteride 5 mg tablets. The ratio of free to total PSA remains constant even under the influence of finasteride 5 mg tablets. If clinicians elect to use percent free PSA as an aid in the detection of prostate cancer in men undergoing finasteride therapy, no adjustment to its value appears necessary.
Women should not handle crushed or broken finasteride 5 mg tablets when they are pregnant or may potentially be pregnant because of the possibility of absorption of finasteride and the subsequent potential risk to the male fetus (see CONTRAINDICATIONS; WARNINGS, EXPOSURE OF WOMEN — RISK TO MALE FETUS; PRECAUTIONS, Pregnancy and HOW SUPPLIED).
Physicians should inform patients that the volume of ejaculate may be decreased in some patients during treatment with finasteride 5 mg tablets. This decrease does not appear to interfere with normal sexual function. However, impotence and decreased libido may occur in patients treated with finasteride 5 mg tablets (see ADVERSE REACTIONS).
Physicians should instruct their patients to promptly report any changes in their breasts such as lumps, pain or nipple discharge. Breast changes including breast enlargement, tenderness and neoplasm have been reported (see ADVERSE REACTIONS).
Physicians should instruct their patients to read the patient package insert before starting therapy with finasteride 5 mg tablets and to reread it each time the prescription is renewed so that they are aware of current information for patients regarding finasteride 5 mg tablets.
In patients with BPH, finasteride 5 mg tablets have no effect on circulating levels of cortisol, estradiol, prolactin, thyroid-stimulating hormone, or thyroxine. No clinically meaningful effect was observed on the plasma lipid profile (i.e., total cholesterol, low density lipoproteins, high density lipoproteins and triglycerides) or bone mineral density. Increases of about 10% were observed in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in patients receiving finasteride 5 mg tablets, but levels remained within the normal range. In healthy volunteers, treatment with finasteride 5 mg tablets did not alter the response of LH and FSH to gonadotropin-releasing hormone indicating that the hypothalamic-pituitary-testicular axis was not affected.
Treatment with finasteride 5 mg tablets for 24 weeks to evaluate semen parameters in healthy male volunteers revealed no clinically meaningful effects on sperm concentration, mobility, morphology, or pH. A 0.6 mL (22.1%) median decrease in ejaculate volume with a concomitant reduction in total sperm per ejaculate was observed. These parameters remained within the normal range and were reversible upon discontinuation of therapy with an average time to return to baseline of 84 weeks.
No drug interactions of clinical importance have been identified. Finasteride does not appear to affect the cytochrome P450-linked drug metabolizing enzyme system. Compounds that have been tested in man have included antipyrine, digoxin, propranolol, theophylline, and warfarin and no clinically meaningful interactions were found.
Other Concomitant Therapy: Although specific interaction studies were not performed, finasteride 5 mg tablets were concomitantly used in clinical studies with acetaminophen, acetylsalicylic acid, α-blockers, angiotensin-converting enzyme (ACE) inhibitors, analgesics, anti-convulsants, beta-adrenergic blocking agents, diuretics, calcium channel blockers, cardiac nitrates, HMG-CoA reductase inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDs), benzodiazepines, H2 antagonists and quinolone anti-infectives without evidence of clinically significant adverse interactions.
No evidence of a tumorigenic effect was observed in a 24-month study in Sprague-Dawley rats receiving doses of finasteride up to 160 mg/kg/day in males and 320 mg/kg/day in females. These doses produced respective systemic exposure in rats of 111 and 274 times those observed in man receiving the recommended human dose of 5 mg/day. All exposure calculations were based on calculated AUC(0-24 hr) for animals and mean AUC(0-24 hr) for man (0.4 μg•hr/mL).
In a 19-month carcinogenicity study in CD-1 mice, a statistically significant (p≤0.05) increase in the incidence of testicular Leydig cell adenomas was observed at a dose of 250 mg/kg/day (228 times the human exposure). In mice at a dose of 25 mg/kg/day (23 times the human exposure, estimated) and in rats at a dose of ≥40 mg/kg/day (39 times the human exposure) an increase in the incidence of Leydig cell hyperplasia was observed. A positive correlation between the proliferative changes in the Leydig cells and an increase in serum LH levels (2- to 3-fold above control) has been demonstrated in both rodent species treated with high doses of finasteride. No drug-related Leydig cell changes were seen in either rats or dogs treated with finasteride for 1 year at doses of 20 mg/kg/day and 45 mg/kg/day (30 and 350 times, respectively, the human exposure) or in mice treated for 19 months at a dose of 2.5 mg/kg/day (2.3 times the human exposure, estimated).
No evidence of mutagenicity was observed in an in vitro bacterial mutagenesis assay, a mammalian cell mutagenesis assay, or in an in vitro alkaline elution assay. In an in vitro chromosome aberration assay, using Chinese hamster ovary cells, there was a slight increase in chromosome aberrations. These concentrations correspond to 4000-5000 times the peak plasma levels in man given a total dose of 5 mg. In an in vivo chromosome aberration assay in mice, no treatment-related increase in chromosome aberration was observed with finasteride at the maximum tolerated dose of 250 mg/kg/day (228 times the human exposure) as determined in the carcinogenicity studies.
In sexually mature male rabbits treated with finasteride at 80 mg/kg/day (543 times the human exposure) for up to 12 weeks, no effect on fertility, sperm count, or ejaculate volume was seen. In sexually mature male rats treated with 80 mg/kg/day of finasteride (61 times the human exposure), there were no significant effects on fertility after 6 or 12 weeks of treatment; however, when treatment was continued for up to 24 or 30 weeks, there was an apparent decrease in fertility, fecundity and an associated significant decrease in the weights of the seminal vesicles and prostate. All these effects were reversible within 6 weeks of discontinuation of treatment. No drug-related effect on testes or on mating performance has been seen in rats or rabbits. This decrease in fertility in finasteride-treated rats is secondary to its effect on accessory sex organs (prostate and seminal vesicles) resulting in failure to form a seminal plug. The seminal plug is essential for normal fertility in rats and is not relevant in man.
Finasteride 5 mg tablets are not indicated for use in women.
It is not known whether finasteride is excreted in human milk.
Finasteride 5 mg tablets are not indicated for use in pediatric patients.
Safety and effectiveness in pediatric patients have not been established.
Of the total number of subjects included in PLESS, 1480 and 105 subjects were 65 and over and 75 and over, respectively. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differencesin responses between the elderly and younger patients. No dosage adjustment is necessary in the elderly (see CLINICAL PHARMACOLOGY, Pharmacokinetics and Clinical Studies).
Finasteride 5 mg tablets are generally well tolerated; adverse reactions usually have been mild and transient.
In PLESS, 1524 patients treated with finasteride 5 mg tablets 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 finasteride 5 mg tablets 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 finasteride 5 mg tablets were ≥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.
2, 3 and 4|
|N = 1524 and 1516, finasteride vs placebo, respectively|
|Decreased Volume of Ejaculate|
The adverse experience profile in the 1-year, placebo-controlled, Phase III studies, the 5-year open extensions, and PLESS were similar.
The incidence rates of drug-related adverse experiences reported by ≥2% of patients in any treatment group in the MTOPS Study are uled 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 (see Table 5). 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. (See ADVERSE REACTIONS, Long-Term Data.)
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.
4 mg or 8 mg
|Body as a whole|
|Metabolic and Nutritional|
|Sexual Function, Abnormal||0.9||2.0||2.5||3.1|
There is no evidence of increased adverse experiences with increased duration of treatment with finasteride 5 mg tablets. 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 finasteride 5 mg tablets 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 prostatecancer. N Engl J Med 2003;349:213-22) is provided for consideration by physicians when finasteride 5 mg tablets are used as indicated (see INDICATIONS AND USAGE). Finasteride 5 mg tablets are not approved to reduce the risk of developing prostate cancer.
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.
Patients have received single doses of finasteride 5 mg tablets up to 400 mg and multiple doses of finasteride 5 mg tablets up to 80 mg/day for three months without adverse effects. Until further experience is obtained, no specific treatment for an overdose with finasteride 5 mg tablets can be recommended.
Significant lethality was observed in male and female mice at single oral doses of 1500 mg/m2 (500 mg/kg) and in female and male rats at single oral doses of 2360 mg/m2 (400 mg/kg) and 5900 mg/m2 (1000 mg/kg), respectively.
The recommended dose is 5 mg orally once a day.
Finasteride 5 mg tablets can be administered alone or in combination with the alpha-blocker doxazosin (see CLINICAL PHARMACOLOGY, Clinical Studies).
Finasteride 5 mg tablets may be administered with or without meals.
No dosage adjustment is necessary for patients with renal impairment or for the elderly (see CLINICAL PHARMACOLOGY, Pharmacokinetics).
No. 8356 Finasteride 5 mg Tablets, USP are blue, modified apple-shaped, film-coated tablets, with the 72 on one side and plain on the other. They are supplied as follows:
NDC 55111-554-30 unit of use bottles of 30
NDC 55111-554-90 unit of use bottles of 90
Store at room temperatures below 30°C (86°F). Protect from light and keep container tightly closed.
Women should not handle crushed or broken Finasteride 5 mg Tablets, USP when they are pregnant or may potentially be pregnant because of the possibility of absorption of finasteride and the subsequent potential risk to a male fetus (see WARNINGS, EXPOSURE OF WOMEN — RISK TO MALE FETUS, and PRECAUTIONS, Information for Patients and Pregnancy).
MERCK & CO., Inc.,
Whitehouse Station, NJ 08889, USA
Dr. Reddy's Laboratories Inc.
Bridgewater, NJ 08807, USA
MERCK & CO., Inc., 1992, 1995, 1998
All rights reserved
Issued February 2006
Printed in USA
Finasteride 5 mg Tablets, USP
Patient Information about
Finasteride 5 mg tablets are for use by men only.
Please read this leaflet before you start taking finasteride 5 mg tablets. Also, read it each time you renew your prescription, just in case anything has changed. Remember, this leaflet does not take the place of careful discussions with your doctor. You and your doctor should discuss finasteride 5 mg tablets when you start taking your medication and at regular checkups.