prazosin (Minipress)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Jay W. Marks, MD
    Jay W. Marks, MD

    Jay W. Marks, MD

    Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

What is prazosin-oral, and how does it work (mechanism of action)?

Prazosin (Minipress) is an oral medicine used to treat high blood pressure. Prazosin is a competitive alpha-1 adrenergic receptor blocker. By blocking alpha-1 receptors on muscle cesll that surround blood vessels, prazosin causes vasodilation (widening) of the blood vessels, and consequently decreases the resistance of blood flow. The overall benefit of its use is a decrease in blood pressure.

Prazosin seems to have a bigger impact on reducing the diastolic blood pressure than systolic blood pressure. Diastolic blood pressure is indicated by the second set of numbers in the blood pressure reading and corresponds to the minimum pressure in the arteries when the heart muscles are relaxed and the chambers of the heart are filling with blood.

Prazosin was approved by the FDA in 1976.

What brand names are available for prazosin-oral?

Minipress

Is prazosin-oral available as a generic drug?

GENERIC AVAILABLE: Yes

Do I need a prescription for prazosin-oral?

Yes

What are the side effects of prazosin-oral?

The most common side effects associated with prazosin treatment include:

Patients can lower their chance of feeling dizzy or passing out by:

  • rising slowing from a sitting or lying position,
  • climbing stairs slowly,
  • avoiding alcohol, and
  • drinking lots of water especially in hot weather or while being active.

 Additionally, patients should have their blood pressure checked regularly.

Less common side effects include:

Rare side effects include:

Other side effects reported in post-marketing trials include:

Medically Reviewed by a Doctor on 6/1/2015

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