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Propecia Actions :
Propecia (finasteride, MSD) is a synthetic 4-azasteroid compound that is a specific inhibitor of Type II 5?-reductase, an intracellular enzyme that metabolizes the androgen testosterone into dihydrotestosterone (DHT).
Indications
For the treatment of men with male pattern hair loss (androgenetic alopecia), to increase hair growth and prevent further hair loss. Propecia is not indicated for use in women or children.
Propecia Dosage :
The recommended dosage is one 1-mg tab daily. Propecia may be taken with or without food. In general, daily use for 3 months or more is necessary before increased hair growth and/or prevention of further hair loss is observed. Continued use is recommended to obtain maximum benefit. Withdrawal of treatment leads to reversibility of effect within 12 months.
Propecia Overdosage :
In clinical studies, single doses of finasteride up to 400 mg and multiple doses of finasteride up to 80 mg/day for 3 months did not result in side effects. No specific treatment for overdosage with Propecia is recommended.
Propecia Contraindication :
Use in women when they are or may potentially be pregnant (see Use in pregnancy under Precautions); hypersensitivity to any component of Propecia. Propecia is not indicated for use in women or children.
Propecia Precautions :
In clinical studies with Propecia in men 18-41 years, the mean value of serum prostate-specific antigen (PSA) decreased from 0.7 ng/mL at baseline to 0.5 ng/mL at Month 12. When Propecia is used for treatment of male pattern hair loss in older men who also have benign prostatic hyperplasia (BPH), consideration should be given to the fact that, in older men with BPH, PSA levels are decreased by approximately 50%. Use in pregnancy: Propecia is contraindicated for use in women when they are or may potentially be pregnant. Because of the ability of Type II 5?-reductase inhibitors to inhibit conversion of testosterone to DHT in some tissues, these drugs, including finasteride, may cause abnormalities of the external genitalia of a male fetus when administered to a pregnant woman. Women should not handle crushed or broken tablets of Propecia when they are or may potentially be pregnant because of the possibility of absorption of finasteride and the subsequent potential risk to a male fetus. Propecia tablets are coated and will prevent contact with the active ingredient during normal handling, provided that the tablets have not been broken or crushed. Use in lactation: Propecia is not indicated for use in women. It is not known whether finasteride is excreted in human milk. Use in children: Propecia is not indicated for use in children. Use in the elderly: Clinical studies with Propecia have not been conducted in elderly men with male pattern hair loss.
Propecia Adverse Reactions :
Propecia is generally well tolerated. Side effects, which usually have been mild, generally have not required discontinuation of therapy. Finasteride for male pattern hair loss has been evaluated for safety in clinical studies involving more than 3200 men. In three 12-month, placebo-controlled, double-blind, multicenter studies of comparable design, the overall safety profiles of Propecia and placebo were similar. Discontinuation of therapy due to any clinical adverse experience occurred in 1.7% of 945 men treated with Propecia and 2.1% of 934 men treated with placebo. In these studies, the following drug-related adverse experiences were reported in ? (greater than or equal to) 1% of men treated with Propecia: Decreased libido (Propecia 1.8% vs placebo 1.3%) and erectile dysfunction (1.3%, 0.7%). In addition, decreased volume of ejaculate was reported in 0.8% of men treated with Propecia and 0.4% of men treated with placebo. Resolution of these side effects occurred in men who discontinued therapy with Propecia and in many who continued therapy. In a separate study, the effect of Propecia on ejaculate volume was measured and was not different from that seen with placebo. The side effect profile for 547 patients who continued on Propecia for up to 24 months was similar to that observed in the 12-month controlled studies. Finasteride is also in use for the treatment of older men with BPH at 5 times the dosage recommended for male pattern hair loss. Additional side effects that have been reported at the 5-mg dosage in men with BPH are: Ejaculation disorder, breast tenderness and enlargement, and hypersensitivity reactions, including lip swelling and rash. In the clinical studies with Propecia, the incidence of these events was not different from placebo.
Propecia Drug Interaction :
No drug interactions of clinical importance have been identified. Finasteride does not appear to affect the cytochrome P-450-linked drug-metabolizing enzyme system. Compounds that have been tested in man have included antipyrine digoxin, glyburide, propranolol, theophylline and warfarin, and no interactions were found. Although specific interaction studies were not performed in clinical studies, finasteride doses of 1 mg or more were used concomitantly with ACE inhibitors, acetaminophen, ?-blockers, benzodiazepines, ?-blockers, calcium-channel blockers, cardiac nitrates, diuretics, H2-antagonists, HMG-CoA reductase inhibitors, prostaglandin synthetase inhibitors (NSAIDs) and quinolones, without evidence of clinically significant adverse interactions.
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