Finasteride is available in 5mg capsules and 1mg capsules. 5mg capsules are for the treatment of patients with prostate enlargement and can be taken orally once a day at 5mg, morning and evening, before and after meals, for long term use. No dosage adjustment is required for patients with renal insufficiency. pharmacokinetics of finasteride in patients over 70 years of age shows a reduced clearance of finasteride and no dosage adjustment is required. If finasteride is used for the treatment of androgenetic alopecia, 1 mg/day orally for 4 months is a course of treatment. 5 mg of finasteride, it is mainly used in patients with an enlarged prostate with lower urinary tract obstruction with prostatic hyperplasia. It is more effective in patients with a larger prostate, for example, greater than 40 ml, or with higher serum prostate antigen levels. Finasteride is contraindicated in women, children and patients with finasteride hypersensitivity. Patients with large amounts of residual urine and severely reduced urinary flow should be monitored closely for urinary tract obstruction.