Prazosin / Minipress

Question 1

Cost

Answer 1

4-20 per month

Question 2

Drug Class (Pharmalogic and Therapeutic)

Answer 2

Pharm: Selective alpha 1 adrenoceptor blocker
Therapeutic: antihypertensive, treatment of BPH

Question 3

Pharmacodynamics

Answer 3

blocks alpha 1 receptors on arterioles and veins, thereby inhibiting NE mediated vasoconstriction and venoconstriction

Question 4

Pharmacokinetics

Answer 4

available po or transdermal; variable oral bioavailability (~60%) onset 2h, duration 12-24 h; extensively metabolized in liver

Question 5

Toxicity

Answer 5

Excessive hypotension with passing out, especially orthostatic, especially in patients on diruetics

Question 6

Interactions

Answer 6

additive effects with most other antihypertensives, especially diuretics

Question 7

Special considerations

Answer 7

start gradually, and at bedtime, to avoid first-time passing out; male patients with BPH (benign prostate hyperplasia)

Question 8

Indications and dose/route

Answer 8

as monotherapy, begin with 1mg tid, advance to 20mg per day divided tid

Question 9

Monitor

Answer 9

BP, weight, edema