Classes
DEA Class; Rx
Common Brand Names; Minipress, Prazin, Prazo
- Alpha Blockers, Antihypertensives
Description
Oral alpha-blocker; used primarily for HTN; similar to doxazosin and terazosin, but is shorter-acting; has also been used for CHF, but is seldom used for this indication due to the development of tolerance for drug efficacy.
Indications
Indicated for the treatment of hypertension.
Contraindications
Hypersensitivity
Adverse Effects
- Dizziness (10%)
- Drowsiness (8%)
- Headache (8%)
- Weakness (7%)
- Asthenia (6.5%)
- Nausea (5%)
- Palpitation (5%)
- Edema
- Orthostatic hypotension
- Syncope
- Fever
- Rash
- Abdominal discomfort/pain
- Diarrhea
- Vomiting
- Abnormal liver function tests
- Impotence
- Pancreatitis
- Urinary incontinence
Warnings
Risk of syncope; has no relation to plasma prazosin concentration; if syncope occurs, place patient in the recumbent position and treat supportively as necessary
Discontinue if angina symptoms occur or worsen
May cause CNS depression, which may impair physical or internal abilities; use caution when performing tasks that require mental alertness
May impair ability to drive/perform hazardous tasks due to dizziness
History of narcolepsy – May exacerbate
Cataract surgery – Linked to intraoperative floppy iris syndrome
Concomitant administration with PDE-5 inhibitor (eg, sildenafil) can result in additive blood pressure-lowering effects and symptomatic hypotension; initiate PDE-5 inhibitor therapy at lowest dose
First dose effect may occur, causing a sudden and drastic fall in blood pressure after administration of the first dose.
May exacerbate heart failure
Pregnancy and Lactation
Pregnancy category: C
Lactation: Excreted in breast milk; use caution
Maximum Dosage
20 mg/day PO for heart failure or hypertension (some patients have required up to 40 mg/day PO for hypertension); 9 mg/day PO for benign prostatic hyperplasia (BPH).
20 mg/day PO for heart failure or hypertension (some patients have required up to 40 mg/day PO for hypertension); 9 mg/day PO for benign prostatic hyperplasia (BPH).
No maximum dosage information is available. See adult and children’s dosage.
15 mg/day PO or 400 mcg/kg/day PO.
How supplied
Prazosin hydrochloride
capsule
- 1mg
- 2mg
- 5mg