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Proscar Finasteride Actions :
Proscar (finasteride, MSD) is a synthetic 4-azasteroid compound. This is the first of a new class of specific inhibitors of 5?-reductase, an intracellular enzyme which metabolizes testosterone into the more potent androgen dihydrotestosterone (DHT). Finasteride has no affinity for the androgen receptor. Benign prostatic hyperplasia (BPH) is a common finding in men >50 years and its prevalence increases with age. The development of the prostate gland and subsequent BPH is dependent upon the conversion of testosterone to DHT within the prostate. As with other androgen-mediated processes, BPH is a slowly progressing disorder and therefore, reversal of the clinical manifestations of BPH may require several months of treatment. Proscar is indicated for the treatment and control of BPH. Proscar is highly effective in reducing circulating and intraprostatic DHT. Within 24 hrs after oral administration of Proscar, there is a significant reduction in circulating DHT levels as a result of the inhibition of 5?-reductase. In long-term clinical trials of patients treated with 5 mg/day Proscar, suppression of DHT was asssociated with a marked regression in prostate volume, increase in maximum urinary flow rate and improvement in total as well as obstructive symptoms. This control of BPH was maintained during a 2-year follow-up thus suggesting that Proscar may reverse the disease process of BPH. Compared to baseline values, patients showed an improvement in all 3 primary efficacy parameters by 3 months. Compared to placebo, a statistically significant difference in the decrease in prostate volume and prostate specific antigen (PSA) occurred after 3 months. Statistically significant differences from placebo were also seen in maximum urinary flow rates by 4 months and in improvement in both total and obstructive symptoms scores by 7 months.
Proscar Finasteride Indications :
For the treatment and control of benign prostatic hyperplasia (BPH) to cause regression of the enlarged prostate, improve urinary flow and improve the symptoms associated with BPH.
Proscar Finasteride Dosage :
The recommended dosage is one 5-mg tab daily with or without food. Although early improvement may be seen, a therapeutic trial of at least 6 months may be necessary to assess whether a beneficial response has been achieved. Renal Insufficiency: Adjustments in dosage are not necessary in patients with varying degrees of renal insufficiency (creatinine clearance as low as 9 mL/min) as pharmacokinetic studies did not indicate any change in the disposition of finasteride. Elderly: No adjustment in dosage is required although pharmacokinetic studies indicated the elimination of finasteride is somewhat decreased in patients >70 years.
Proscar Finasteride Contraindication :
Hypersensitivity to any component of Proscar. Use in pregnancy & lactation: Proscar is contraindicated in women who are or may become pregnant (see Precautions). Because of the ability of 5?-reductase inhibitors to inhibit conversion of testosterone to dihydrotestosterone, these drugs, including finasteride, may cause abnormalities of the external genitalia of a male fetus when administered to pregnant women. Proscar is not indicated for use in women. It is not known whether finasteride is excreted in human milk. Use in children: Proscar is not indicated for use in children. Safety and effectiveness in children have not been established.
Proscar Finasteride Adverse Reactions :
Proscar is well tolerated. Seven patients were discontinued from controlled clinical studies of 12-month duration involving 543 patients treated with 5 mg of Proscar due to side effects attributable to Proscar. Adverse experiences related to sexual function were the most frequently reported side effects, however, of the above 7 patients, only 1 discontinued therapy with Proscar because of these experiences. In these studies, adverse effects considered by the investigator as possibly, probably, or definitely drug-related occurring with a frequency of >1% and greater than with placebo were: Impotence (3.7%), decreased libido (3.3%) and decreased volume of ejaculate (2.8%, 0.9%). The adverse experience profile for approximately 100 other patients who were treated with 5 mg Proscar for up to 24 months (controlled studies of 6- to 12-month duration and their extensions) was similar to that observed in the previously-mentioned studies. Laboratory Test Findings: When PSA laboratory determinations are evaluated, consideration should be given to the fact that PSA levels are decreased in patients treated with Proscar (see Precautions). No other difference was observed between placebo and Proscar treated patients in standard laboratory parameters.
Proscar Finasteride Drug Interaction :
No drug interactions of clinical importance have been identified. Proscar does not appear to affect significantly the cytochrome P-450-linked drug metabolizing enzyme system. Compounds which have been tested in man have included propranolol, digoxin, glyburide, warfarin, theophylline and antipyrine. Other Concomitant Therapy: Although specific interaction studies were not performed, in clinical studies Proscar was used concomitantly with ACE-inhibitors, ?-blockers, ?-blockers, calcium-channel blockers, cardiac nitrates, diuretics, H2-antagonists, HMG-CoA reductase inhibitors, nonsteroidal anti-inflammatory drugs (NSAIDS), quinolones and benzodiazepines without evidence of clinically significant adverse interactions.
Proscar Finasteride Storage :
Store below 30C (86F) and protect from light.
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