prazosin (Minipress) (cont.)

Pharmacy Author:
Medical and Pharmacy Editor:

Rare side effects include:

Other side effects reported in post-marketing trials include:



PREPARATIONS: Oral capsules: 1, 2, and 5 mg.

STORAGE: Capsules should be stored at room temperature, between 59 F and 86 F (15 C and 30 C).


  • The dose of prazosin should be adjusted based on the individual patient response.
  • For the treatment of high blood pressure: Most patients are started with 1 mg by mouth 2-3 times a day. To decrease the risk of orthostatic hypotension the first dose may be given at bedtime. Orthostatic hypotension is a drop in blood pressure when standing up from a sitting or lying position. Dosage may be increased gradually over time to a total daily dose of 20 mg given in multiple doses.
  • If adding another blood pressure lowering agent or water pill (diuretic) to prazosin therapy, the dose of prazosin should be reduced to 1-2 mg by mouth three times a day, followed by slow increases in dose as needed.
  • As elderly patients are more sensitive to the side effects of low blood pressure, dose reduction in the elderly is necessary. Most elderly patients are started on 1 mg by mouth 1-2 times daily.
  • The safety and effectiveness of prazosin in children has not been established.
Medically Reviewed by a Doctor on 6/1/2015

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