hydralazine
Brand names: Apresoline
Hydralazine is a drug that lowers blood pressure by relaxing blood vessels. It can be used alone or with other medications.
Drug Pricing (NADAC)
Generic Price
$0.03/unit
Generic Available
Yes (21 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Hydralazine is used to treat high blood pressure (hypertension).
Common side effects
Headache, Loss of appetite, Nausea
Key warnings
Taking high doses of hydralazine can cause a drug-induced lupus erythematosus (L.
How It Works
Hydralazine works by relaxing the muscles in your blood vessels. This allows blood to flow more easily. As a result, your blood pressure goes down.
How to Take It
Start with a low dose and increase it slowly as directed by your doctor. You will likely start with 10 mg four times a day for 2-4 days. Then, your doctor may increase the dose to 25 mg four times a day for the rest of the first week. In the second week, the dose may increase to 50 mg four times a day. Take this medicine exactly as prescribed by your doctor.
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if hydralazine will harm an unborn baby. Talk to your doctor about the risks and benefits of taking hydralazine during pregnancy or while breastfeeding.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
Storage
Store hydralazine tablets at room temperature (68° to 77°F) in a tightly closed, light-resistant container, and keep out of reach of children.
Side Effects (from patient reports)
Based on 17,575 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 28,498 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 1995–2025.
Total Reports
28,498
Death-Related Reports
3,510
Hospitalization Reports
12,190
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | CHRONIC KIDNEY DISEASE | 2,819 |
| 2 | ACUTE KIDNEY INJURY | 2,616 |
| 3 | RENAL FAILURE | 2,097 |
| 4 | END STAGE RENAL DISEASE | 1,585 |
| 5 | FATIGUE | 1,542 |
| 6 | DYSPNOEA | 1,535 |
| 7 | DIARRHOEA | 1,407 |
| 8 | NAUSEA | 1,337 |
| 9 | DRUG INEFFECTIVE | 1,326 |
| 10 | DEATH | 1,316 |
| 11 | HYPERTENSION | 1,312 |
| 12 | OFF LABEL USE | 1,168 |
| 13 | ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY POSITIVE VASCULITIS | 1,005 |
| 14 | ASTHENIA | 973 |
| 15 | DIZZINESS | 958 |
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
Taking high doses of hydralazine can cause a drug-induced lupus erythematosus (L.E.) cell syndrome. Your doctor will monitor your dose to avoid this.
Known Drug Interactions
Although not studied with alosetron, inhibition of N-acetyltransferase may have clinically relevant consequences for drugs such as isoniazid, procainamide, and hydralazine.
Mechanism: Alosetron may interfere with the way your body processes hydralazine, potentially leading to higher drug levels.
What to do: Talk to your doctor about monitoring your blood pressure and watching for any new symptoms.
Other Cardiovascular Agents Enalapril maleate has been used concomitantly with beta adrenergic-blocking agents, methyldopa, nitrates, calcium-blocking agents, hydralazine, prazosin and digoxin without evidence of clinically significant adverse interactions.
Mechanism: These two blood pressure medicines work in different ways to relax your blood vessels and have not been shown to cause harmful interactions when used together.
What to do: These drugs are generally safe to take together, but you should still watch for signs of very low blood pressure like dizziness.
Pindolol has been used with a variety of antihypertensive agents, including hydrochlorothiazide, hydralazine, and guanethidine without unexpected adverse interactions.
Mechanism: These two blood pressure medicines can be used together safely. They do not have any harmful interactions when taken at the same time.
What to do: You can take these medications together as prescribed. Your doctor will monitor your blood pressure to ensure the treatment is working.
Common Questions
Can I stop taking hydralazine if I feel better?
Will hydralazine cure my high blood pressure?
Can I drink alcohol while taking hydralazine?
What should I do if I feel dizzy after taking hydralazine?
Does hydralazine interact with other medications?
Can hydralazine cause weight gain?
How long does it take for hydralazine to start working?
Can I take hydralazine if I have kidney problems?
Is it safe to drive while taking hydralazine?
What are the symptoms of L.E. cell syndrome?
What are the common side effects of hydralazine?
Does hydralazine interact with other medications?
What drug class is hydralazine?
Is hydralazine safe during pregnancy?
Has hydralazine been recalled?
Active Recalls
CGMP Deviations: Firm went out of business and could no longer continue stability studies.
Akorn, Inc.
Related Medications in Vasodilator
Other drugs grouped near hydralazine — same-class peers and common alternatives.
acebutolol
Sectral
Acebutolol is a medicine that helps lower blood pressure and control irregular heartbeats.
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aliskiren
Tekturna
Tekturna is a medicine used to treat high blood pressure.
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amiloride
Midamor
Amiloride is a water pill that helps your body hold onto potassium.
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amlodipine
Norvasc
Amlodipine (Norvasc) is a drug that lowers blood pressure and treats chest pain.
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amlodipine/benazepril
Lotrel
Lotrel is a combination medicine that contains amlodipine and benazepril.
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What the FDA Data Shows for hydralazine
The FDA label for hydralazine (sold under brand names such as Apresoline) classifies it as a prescription-only medication in the Vasodilator class. Hydralazine is used to treat high blood pressure (hypertension). Official labeling lists 7 commonly reported side effects, including Headache, Loss of appetite, Nausea.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 17,575 voluntary reports. The database also lists 3 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 $0.03.
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 1 recall record 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).
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: July 1, 2025
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