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Prazosin oral capsule dosage: A detailed guide

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Form and strengthsDosageFAQHow it's takenCouponOverdoseAsk your doctor
Doctors prescribe prazosin oral capsule for high blood pressure in adults. You take it by mouth two or three times per day.
Medically reviewed by Melissa Badowski, PharmD, MPH, FCCP
Updated on December 7, 2023

This article describes prazosin oral capsule’s dosage and strengths and gives details on how to take it. You’ll also find information on cost savings and coupon options for prazosin.

If you want to know more about prazosin oral capsule, see this overview article. It covers details about the drug’s uses and side effects, ways to save on cost, and more.

Prazosin oral capsule is a generic version of the brand-name drug Minipress.

Form and strengths of prazosin

Prazosin oral capsule comes as follows:

  • Form: oral capsule that you swallow
  • Strengths: 1 milligram (mg), 2 mg, and 5 mg

Dosage of prazosin

This article describes the recommended dosages for prazosin oral capsule. The drugmaker provides these dosages.

If your doctor prescribes this medication, you should follow the dosage they prescribe. Your doctor will determine the dosage that best meets your needs. Do not change your dosage of prazosin oral capsule without your doctor’s recommendation.

Usual recommended dosage of prazosin in adults

Usually, doctors start by prescribing a low dosage of prazosin oral capsule. Then, they’ll adjust it over time until the right dosage is reached. Ultimately, your doctor will prescribe the smallest dosage of prazosin oral capsule that gives the desired outcome.

Note that your first dose of prazosin could make you feel dizzy or lightheaded, or make you faint or pass out. This may happen within 30–90 minutes after taking your first dose. Because of this, your doctor will likely recommend taking your first dose of prazosin oral capsule at bedtime.

Dosage for high blood pressure

  • Starting dosage: 1 milligram (mg) taken two or three times per day, as directed by your doctor.
  • Maintenance dosage: 6 mg–15 mg daily, split into equal doses taken two or three times per day, as directed by your doctor.
  • Maximum dosage: 20 mg daily*, split into equal doses taken two or three times per day, as directed by your doctor.

*Higher doses don’t usually have an extra effect, but doctors may occasionally prescribe up to 40 mg daily for certain people.

Dosage adjustments for prazosin

Your doctor will prescribe a dosage of prazosin oral capsule based on several factors. These include:

Missed dose of prazosin

Talk with your doctor or pharmacist right away if you realize you forgot to take a dose of prazosin oral capsule. They may advise you to take the missed dose. Or they may advise you to skip it and take your next dose as scheduled.

For tips on how to plan your doses of prazosin oral capsule and avoid missing a dose, read this article. You could also try:

  • downloading a reminder app on your phone
  • setting an alarm
  • putting a note where you’ll see it, such as on your calendar, bathroom mirror, or bedside table

Frequently asked questions

Below are answers to some commonly asked questions about prazosin oral capsule and its dosage.

Can prazosin be used for nightmares, anxiety, sleep, or urinary retention? If so, what is the dosage?

Doctors may sometimes prescribe prazosin for nightmares related to post-traumatic stress disorder (PTSD). Nightmares can lead to anxiety and sleep disturbances in people with PTSD. This is an off-label use of prazosin. With off-label use, doctors prescribe a drug for a purpose other than what it’s approved for.

Doctors may also prescribe prazosin off-label for urinary retention related to an enlarged prostate gland. With urinary retention, you have trouble urinating and emptying your bladder.

For more information about these off-label uses of prazosin, including the dosage that may be prescribed, talk with your doctor.

Is prazosin taken long term?

Yes, doctors typically prescribe prazosin oral capsule as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take it long term.

If you have questions about how long you should take prazosin oral capsule, talk with your doctor.

How prazosin is taken

You’ll swallow prazosin oral capsule two or three times per day, as instructed by your doctor. You can take the capsule with or without food.

The drugmaker doesn’t state whether you can split, crush, or chew prazosin oral capsule.

If it’s hard for you to swallow capsules, view this article. It provides suggestions on how to swallow medications that come in pill form.

Also, be sure to talk with your doctor or pharmacist if you’re having difficulty taking your medication. They can offer recommendations about taking it.

Prazosin coupon

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Overdose of prazosin

It’s important that you do not take more prazosin oral capsule than your doctor prescribes. Doing so can lead to harmful effects.

Symptoms of prazosin overdose

Symptoms of an overdose can include:

What to do if you take too much prazosin

If you think you’ve taken too much prazosin, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have severe symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

What to ask your doctor

This article describes the usual recommended dosage for prazosin oral capsule. If your doctor prescribes this medication, they’ll determine the dosage that’s best for you.

Do not change your dosage of prazosin oral capsule without your doctor’s recommendation. You should take prazosin oral capsule exactly as your doctor prescribes it. Let your doctor know if you have concerns or questions about your treatment plan.

Here’s a list of some possible questions you may want to ask your doctor:

  • How long do I need to take prazosin oral capsule?
  • Will my dosage of prazosin change if my current dosage isn’t working for my condition?
  • If prazosin makes me feel dizzy, will you decrease my dosage?
  • If I start any new medications, will you adjust my dosage of prazosin?

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

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