II. Indications

  1. Hypertension
    1. Not first-line Antihypertensives, and avoid using as monotherapy (higher risk of CVA and CHF)

III. Efficacy

  1. Terazosin and Doxazosin are preferred over Prazosin (once daily dosing at similar cost)

IV. Dosing

  1. Hypertension
    1. Start 1 mg orally twice daily to three times daily
    2. Titrate to usual daily total dose 20 mg divided two to three times daily
    3. Maximum total daily dose: 40 mg/day (but doses above 20 mg/day offer little additional benefit)

V. Safety

  1. Pregnancy Category C
  2. Unknown safety in Lactation

VI. Mechanism

  1. See Alpha Adrenergic Receptor (Alpha-1 Antagonist)
  2. Peripheral Alpha-1 Adrenergic Antagonist
    1. Arterial and Venous Vasodilation

VII. Adverse Effects

IX. References

  1. (2020) Med Lett Drugs Ther 62(1598): 73-80
  2. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 62-3
  3. Hamilton (2020) Tarascon Pocket Pharmacopoeia

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Related Studies

Cost: Medications

prazosin (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
PRAZOSIN 1 MG CAPSULE Generic $0.18 each
PRAZOSIN 2 MG CAPSULE Generic $0.26 each
PRAZOSIN 5 MG CAPSULE Generic $0.50 each

Ontology: Prazosin (C0032912)

Definition (MSH) A selective adrenergic alpha-1 antagonist used in the treatment of HEART FAILURE; HYPERTENSION; PHEOCHROMOCYTOMA; RAYNAUD DISEASE; PROSTATIC HYPERTROPHY; and URINARY RETENTION.
Definition (NCI) A synthetic piperazine derivative and an alpha-1 adrenergic receptor inhibitor used primarily as an anti-hypertensive. Prazosin's effects are most pronounced in the large resistance vessels (i.e. arterioles) and result in a decrease in total systemic vascular resistance (SVR) without a rebound or reflex tachycardia. To a lesser extent, this agent also decreases the tone of the bladder sphincter, thereby allowing the opening of the bladder into the urethra and thus relieving the urinary conditions associated with benign prostatic hypertrophy.
Definition (CSP) 1-(4-amino-6,7-dimethoxy- 2-quinazolinyl) -4-(2-furoyl) piperazine.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D011224
SnomedCT 367555002, 387283005, 387433003, 76058001, 51505001
LNC LP18588-1, MTHU004704
English Furazosin, Prazosin, Piperazine, 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-furanylcarbonyl)-, 2-[4-(2-furoyl)piperazin-1-yl]-4-amino-6,7-dimethoxyquinazoline, 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-furanylcarbonyl)piperazine, Prazosin [Chemical/Ingredient], PRAZOSIN, prazosin (medication), Furazosin (product), prazosin, Prazosin (product), Prazosin (substance), Furazosin (substance)
Swedish Prazosin
Czech prazosin
Finnish Pratsosiini
Russian PRAZOZIN, ADVERZUTEN, FURAZOZIN, PRATSIOL, АДВЕРЗУТЕН, ПРАЗОЗИН, ПРАТСИОЛ, ФУРАЗОЗИН
Japanese プラゾシン, 塩酸プラゾシン, フラゾシン
Italian Furazosina, Prazosina
Spanish prazosina (producto), prazosín (producto), furazosín, furazosina, furazosín (producto), furazosina (sustancia), prazosina (sustancia), prazosina, prazosín, Furazosina, Prazosina
Polish Prazosyna
French Prazosine
German Furazosin, Prazosin
Portuguese Furazosin, Prazosina

Ontology: Minipress (C0242447)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D011224
English Pfizer Brand of Prazosin Hydrochloride, minipress, Minipress