prazosin
Brand names: Minipress
Prazosin (Minipress) is a medicine that lowers your blood pressure. Lowering blood pressure helps prevent strokes and heart attacks.
Drug Shortage Alert
prazosin is currently listed as to be discontinued by the FDA. Affected manufacturer: Pfizer Inc..
View all drug shortages →Drug Pricing (NADAC)
Generic Price
$0.11/unit
Generic Available
Yes (10 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Prazosin is used to treat high blood pressure.
Common side effects
Dizziness, Headache, Drowsiness
Key warnings
Prazosin can cause a sudden drop in blood pressure, especially when you first start taking it.
How It Works
Prazosin belongs to a class of drugs called alpha-1 blockers. It works by relaxing your blood vessels. This makes it easier for blood to flow through your body, which lowers blood pressure.
How to Take It
Take prazosin as your doctor tells you. The starting dose is usually 1 mg two or three times a day. Your doctor may slowly increase the dose up to 20 mg per day, divided into multiple doses. Some people may need up to 40 mg per day. You can take it with or without food.
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if prazosin will harm your unborn baby. Talk to your doctor about the risks and benefits of taking prazosin while pregnant or breastfeeding.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is close to your next dose, skip the missed dose and continue with your regular schedule.
Storage
Store prazosin at room temperature, between 68°F and 77°F.
Side Effects (from patient reports)
Based on 2,893 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 5,825 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2001–2025.
Total Reports
5,825
Death-Related Reports
676
Hospitalization Reports
2,125
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DRUG INEFFECTIVE | 388 |
| 2 | NAUSEA | 361 |
| 3 | OFF LABEL USE | 360 |
| 4 | HEADACHE | 265 |
| 5 | DIZZINESS | 263 |
| 6 | ANXIETY | 260 |
| 7 | FATIGUE | 257 |
| 8 | PAIN | 254 |
| 9 | VOMITING | 246 |
| 10 | DEPRESSION | 239 |
| 11 | DRUG INTERACTION | 233 |
| 12 | DIARRHOEA | 227 |
| 13 | SUICIDAL IDEATION | 220 |
| 14 | DYSPNOEA | 212 |
| 15 | FALL | 211 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Prazosin can cause a sudden drop in blood pressure, especially when you first start taking it. This can make you feel dizzy or faint. To avoid this, take your first dose at bedtime. Be careful when standing up quickly.
Known Drug Interactions
Drug Interactions Prazosin hydrochloride has been administered without any adverse drug interaction in limited clinical experience to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout– allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol ( see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories– propoxyphene, aspirin, indome...
Mechanism: There is no evidence that these two medications cause problems when taken together.
What to do: You can continue to take both of these medicines as prescribed by your doctor.
Drug Interactions Prazosin hydrochloride has been administered without any adverse drug interaction in limited clinical experience to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout– allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol ( see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories– propoxyphene, aspirin, indome...
Mechanism: Prazosin and aspirin do not have a known negative reaction when used together. They appear to work safely in the body without interfering with each other.
What to do: You can take these medications together as prescribed. No special changes are usually needed.
Drug Interactions Prazosin hydrochloride has been administered without any adverse drug interaction in limited clinical experience to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout– allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol ( see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories– propoxyphene, aspirin, indome...
Mechanism: These two drugs have been used together without causing any harmful side effects. They do not seem to change how the other medication works in the body.
What to do: These drugs are generally safe to use together. Follow your doctor's standard instructions for each medication.
Drug Interactions Prazosin hydrochloride has been administered without any adverse drug interaction in limited clinical experience to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout– allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol ( see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories– propoxyphene, aspirin, indome...
Mechanism: There is no evidence that these drugs cause problems when taken at the same time. They do not appear to affect each other's safety or effectiveness.
What to do: You can continue taking both medications as directed by your healthcare provider. No dosage adjustments are typically required.
Drug Interactions Prazosin hydrochloride has been administered without any adverse drug interaction in limited clinical experience to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout– allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol ( see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories– propoxyphene, aspirin, indome...
Mechanism: Based on limited clinical data, these drugs do not have a known harmful interaction. They appear to be compatible when taken together.
What to do: This combination is considered safe based on current information. No special monitoring or dose changes are usually necessary.
Common Questions
Can I drink alcohol while taking prazosin?
Will prazosin cure my high blood pressure?
Can I stop taking prazosin if I feel better?
Does prazosin interact with other medications?
How long does it take for prazosin to start working?
Can prazosin cause weight gain?
Can I take prazosin if I have kidney problems?
Can prazosin affect my cholesterol?
Is it safe to drive while taking prazosin?
What should I do if I feel dizzy after taking prazosin?
What are the common side effects of prazosin?
Does prazosin interact with other medications?
What drug class is prazosin?
Is prazosin safe during pregnancy?
Has prazosin been recalled?
Is prazosin currently in shortage?
Active Recalls
Failed Impurities/Degradation Specification: presence of N-nitroso Prazosin impurity C above the Carcinogenic Potency Categorization Approach (CPCA) acceptable intake limit
Amerisource Health Services LLC
CGMP Deviations-Test results for N-nitroso Prazosin impurity C that are above the Carcinogenic Potency Categorization Approach (CPCA) acceptable intake limit for the above specified lots.
Teva Pharmaceuticals USA, Inc
CGMP Deviations-Test results for N-nitroso Prazosin impurity C that are above the Carcinogenic Potency Categorization Approach (CPCA) acceptable intake limit for the above specified lots.
Teva Pharmaceuticals USA, Inc
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What the FDA Data Shows for prazosin
The FDA label for prazosin (sold under brand names such as Minipress) classifies it as a prescription-only medication in the Alpha-1 Blocker class. Prazosin is used to treat high blood pressure. Official labeling lists 6 commonly reported side effects, including Dizziness, Headache, Drowsiness.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 2,893 voluntary reports. The database also lists 11 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.11.
Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 3 recall records on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: April 4, 2023
Read our methodology — how this data is sourced, computed, and verified.
All federal data sources used on this page
- FDA Orange Book — approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed — NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) — post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm — standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files — federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database — current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages