Prazosin (Minipress) is an alpha blocker that's used to lower high blood pressure. It works by relaxing your blood vessels, so blood flows through more easily. Prazosin (Minipress) is taken by mouth, typically 2 to 3 times a day. But it isn't a first-choice medication to lower blood pressure because it can cause bothersome side effects like dizziness, headache, and sleepiness.
Prazosin (Minipress) is an alpha blocker. It lowers blood pressure by relaxing blood vessels. This helps blood flow smoothly through the body.
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Contact your healthcare provider immediately if you experience any of the following.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
Dizziness or lightheadedness, especially when getting up from a lying or sitting position
fainting (sudden)
Less common
Loss of bladder control
pounding heartbeat
swelling of the feet or lower legs
Incidence not known
Painful or prolonged erection of the penis
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Drowsiness
headache
lack of energy
Less common
Dryness of the mouth
nervousness
unusual tiredness or weakness
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Prazosin (Minipress) is only FDA-approved to lower high blood pressure. But providers sometimes prescribe it off-label to help with nightmares related to post-traumatic stress disorder (PTSD), which is a mental health condition. There have been many research studies that looked into whether prazosin (Minipress) works well to ease PTSD-related nightmares. While some studies did report that this medication improved sleep quality and lessened nightmares, other studies showed that it didn't help with this condition. Because of the mixed results, the Department of Veterans Affairs says there's not enough evidence to recommend prazosin (Minipress) for PTSD-related nightmares. If you have more questions about prazosin (Minipress) and PTSD, talk with your provider.
No, prazosin (Minipress) isn't a controlled substance. Controlled substances are medications that are linked with a risk of physical or mental dependence. Prazosin (Minipress) isn't known to have this risk.
How long prazosin (Minipress) side effects last depends on which side effects you're experiencing. For example, some of the more common side effects include dizziness, drowsiness, and headaches. People tend to experience these side effects more when first starting prazosin (Minipress) or when their provider raises their dose. But these side effects are temporary and do go away with time. Your provider can also give you tips to manage them in the meantime. But there are other side effects of prazosin (Minipress) that need immediate medical attention, such as priapism (painful erection). If you have more questions about prazosin (Minipress) and side effects, let your provider know.
Drowsiness is a pretty common side effect of prazosin (Minipress), especially if you are taking it for the first time or if you recently raised the dose. Talk with your provider if you continue to feel drowsy, especially during the day. This side effect should be temporary and tend to get better over time. But until then, your provider might ask you to avoid or find alternatives to activities that need a lot of focus and attention, such as driving. If the sleepiness doesn't get better with time, let your provider know. They might lower your dose of prazosin (Minipress) or talk with you about other options to lower blood pressure.
It's best to avoid drinking alcohol when you're taking prazosin (Minipress) (and other blood pressure medications) because this combination can raise your risk for certain side effects, like dizziness and drowsiness. But if you are used to drinking alcohol regularly and have a hard time cutting it out completely, talk with your provider. They can discuss with you how much alcohol to cut back or provide resources to help you quit.
Prazosin (Minipress) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Prazosin (Minipress) can cause you to feel dizzy or faint when you stand up after sitting or lying down. This is because your blood pressure might change quickly when you suddenly change positions (also known as orthostatic hypotension). The risk of this side effect is highest after your first dose of prazosin (Minipress), whenever your dose is raised, or when your provider add on another blood pressure medication. Typically, you tend to feel most dizzy within 90 minutes of taking a dose.
To minimize your risk of dizziness or fainting, you provider will have you start with a lower dose of prazosin (Minipress) and raise your dose slowly over time, if needed. Avoid activities that could be dangerous for the first 24 hours after you start prazosin (Minipress). This includes driving, operating heavy machinery, and exercising. If you feel dizzy, lightheaded, or like your heart is pounding, make sure to stop doing anything that could be hazardous. If these symptoms are bothersome, let your healthcare provider know because they might need to change your dose.
In some rare cases, prazosin (Minipress) can cause a painful erection (also known as priapism) that continues for more than 4 hours. If this happens to you, contact your provider right away to avoid the risk of permanent erectile dysfunction.
If you take prazosin (Minipress) and plan to get cataract eye surgery, let your provider know. In some rare cases, this medication can cause changes to your iris, a condition called Intraoperative Floppy Iris Syndrome (IFIS). Keep in mind that prazosin (Minipress) is probably less likely to cause IFIS than other similar medications, like tamsulosin (Flomax). You don’t need to stop taking prazosin (Minipress) before the surgery, but your surgeon needs to adjust how they perform the operation. Letting your provider know ahead of time can help them prepare accordingly.
| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 1mg | 30 capsules | $12.34 | $0.41 |
| 2mg | 30 capsules | $12.18 | $0.41 |
| 5mg | 30 capsules | $14.00 | $0.47 |
The typical starting dose is 1 mg by mouth 2 to 3 times a day. If needed, your provider will adjust your dose slowly over time. The typical recommended dose ranges from 6 mg to 15 mg daily total, divided into smaller doses and taken throughout the day. The maximum recommended dose is 20 mg daily total.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.