Prescription medication · Alpha-1 Blocker
prazosin
Also sold as Minipress. Prazosin is used to treat high blood pressure.
Data updated 2026-05-15
- 5,825
- FDA reportsLightly reported
- 11
- InteractionsSeveral interactions
- In shortage
- FDA status
What the data shows
prazosin (Minipress) is a prescription Alpha-1 Blocker, reported less often than most tracked drugs (5,825 FDA reports), with 11 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
prazosin (Minipress) is a prescription Alpha-1 Blocker. Prazosin is used to treat high blood pressure.
Prazosin (Minipress) is a medicine that lowers your blood pressure. Lowering blood pressure helps prevent strokes and heart attacks.
Verify with FDA → · CMS NADAC pricing →
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.
The sections below are summarized in plain English from prazosin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
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.
This is a plain-language summary of prazosin's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
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.
This is a plain-language summary of prazosin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
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.
This is a plain-language summary of prazosin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store prazosin at room temperature, between 68°F and 77°F.
Side Effects (from patient reports)
Based on 5,825 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for prazosin, by number of reports
- Feeling sick to your stomach
Feeling sick to your stomach
361 reports
- Head pain
Head pain
265 reports
- Feeling lightheaded or unsteady
Feeling lightheaded or unsteady
263 reports
- Feeling worried or nervous
Feeling worried or nervous
260 reports
- Feeling tired
Feeling tired
257 reports
- Discomfort
Discomfort
254 reports
- Throwing up
Throwing up
246 reports
- Feeling sad or hopeless
Feeling sad or hopeless
239 reports
- The medicine is reacting with another medicine
The medicine is reacting with another medicine
233 reports
- Loose or watery stools
Loose or watery stools
227 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for prazosin each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where prazosin sits
prazosin has more FDA adverse-event reports than 27% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is prazosin; the line is the median (50th percentile).
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
Reports Mentioning Death
676
11.6% of reports — not proof of cause
Hospitalization Reports
2,125
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | NAUSEA | 361 |
| 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 |
| 16 | TOXICITY TO VARIOUS AGENTS | 203 |
| 17 | HYPOTENSION | 201 |
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,...
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,...
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,...
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,...
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,...
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.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
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
cGMP deviation: detection of Nitrosamine Drug Substance-Related Impurities, N-nitroso-prazosin impurity C (NNP) above acceptable limits.
Appco Pharma LLC
cGMP deviation: detection of Nitrosamine Drug Substance-Related Impurities, N-nitroso-prazosin impurity C (NNP) above acceptable limits.
Appco Pharma LLC
cGMP deviation: detection of Nitrosamine Drug Substance-Related Impurities, N-nitroso-prazosin impurity C (NNP) above acceptable limits.
Appco Pharma LLC
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 5,825 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 6 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.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
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