This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in


Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

This is an alpha-adrenoceptor blocker.

The first dose of prazosin may provoke hypotensive collapse so it should be given in the evening with the patient in bed. Blood pressure should be monitored.

The indications for prazosin are:

  • cardiovascular disease:

  • hypertension:
    • 500 mcg 2-3x/day
    • increase dose to 1 g 2-3x/day after a week
    • maximum daily dose is 20 mg

  • congestive cardiac failure:
    • 500 mcg 2-4x/day
    • increase dose to 1 g 4x/day after a week
    • maximum daily dose is 20 mg

  • Raynaud's syndrome:
    • 500 mcg 2x/day
    • increase dose to 1-2 g 2x/day after a week

  • symptomatic benign prostatic hyperplasia:
    • causes relaxation of smooth muscle in the bladder neck
    • 500 mcg 2x/day
    • after a week increase dose according to response
    • usual maintenance dose is 2 mg 2x/day

Related pages

Create an account to add page annotations

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.