Prescription medication · Vasodilator / Nitrate Combination

hydralazine/isosorbide dinitrate

Also sold as BiDil. BiDil is used to treat heart failure in self-identified Black patients.

Data updated 2026-05-15

17,561
FDA reports
2
InteractionsFew interactions
$4.38
Brand price (NADAC)

What the data shows

hydralazine/isosorbide dinitrate (BiDil) is a prescription Vasodilator / Nitrate Combination, with 17,561 FDA adverse-event reports on file, with 2 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.

hydralazine/isosorbide dinitrate (BiDil) is a prescription Vasodilator / Nitrate Combination. BiDil is used to treat heart failure in self-identified Black patients.

BiDil is a medicine that combines two drugs to help treat heart failure. It contains isosorbide dinitrate and hydralazine hydrochloride, which work together to widen blood vessels.

Verify with FDA → · CMS NADAC pricing →

Drug Pricing (NADAC)

Brand Price

$4.38/unit

Generic Available

No

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

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What it does

BiDil is used to treat heart failure in self-identified Black patients.

Common side effects

Headache, Dizziness

Key warnings

BiDil can cause low blood pressure, especially when you stand up.

The sections below are summarized in plain English from hydralazine/isosorbide dinitrate's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

BiDil contains two medicines that work in different ways to widen your blood vessels. Isosorbide dinitrate widens both arteries and veins. Hydralazine hydrochloride mainly widens arteries.

Side Effects (from patient reports)

Based on 17,561 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for hydralazine/isosorbide dinitrate, by number of reports

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.

Source FDA Adverse Event Reporting System (FAERS)

Serious Warnings

BiDil can cause low blood pressure, especially when you stand up. This is more likely if you are dehydrated or have low salt levels. Hydralazine hydrochloride, one of the medicines in BiDil, can cause a lupus-like syndrome. If you have symptoms, your doctor may tell you to stop taking BiDil. BiDil can also worsen chest pain, especially if you have certain heart conditions.

Known Drug Interactions

major sildenafil

7 DRUG INTERACTIONS 7.1 Phosphodiesterase Inhibitors BiDil is contraindicated in patients who are using a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), PDE5 inhibitors such as avanafil, sildenafil, vardenafil, and tadalafil have been shown to potentiate the hypotensive effects of organic nitrates.

Mechanism: Both drugs work to relax blood vessels, and taking them together can cause your blood pressure to drop to a dangerously low level.

major tadalafil

7 DRUG INTERACTIONS 7.1 Phosphodiesterase Inhibitors BiDil is contraindicated in patients who are using a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), PDE5 inhibitors such as avanafil, sildenafil, vardenafil, and tadalafil have been shown to potentiate the hypotensive effects of organic nitrates.

Mechanism: These medicines both lower blood pressure in a similar way, and using them at the same time can cause a severe and unsafe drop in blood pressure.

This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

What should I avoid while taking BiDil?
You should avoid taking PDE5 inhibitors (like sildenafil, tadalafil, vardenafil, or avanafil) or riociguat while taking BiDil, as this can cause dangerously low blood pressure.
Can I drive while taking BiDil?
BiDil can cause dizziness or lightheadedness. Be careful when driving or operating machinery until you know how BiDil affects you.
How long does it take for BiDil to work?
BiDil starts working right away to widen your blood vessels. It may take a few weeks to notice the full benefits, such as improved breathing and less swelling.
What if I have liver problems?
Talk to your doctor if you have liver problems, as BiDil may need to be used with caution.
Can I take BiDil with other medications?
Tell your doctor about all the medications you take, including over-the-counter drugs and supplements, before starting BiDil.
What are the ingredients in BiDil?
Each BiDil tablet contains 20 mg of isosorbide dinitrate and 37.5 mg of hydralazine hydrochloride, along with inactive ingredients.
What do the tablets look like?
BiDil tablets are orange, film-coated, and have "20" on one side and "N" on the other.
How do I dispose of unused BiDil?
Talk to your pharmacist about the best way to dispose of unused BiDil. Do not flush it down the toilet.
What if I have side effects?
Tell your doctor if you have any side effects while taking BiDil. They may be able to adjust your dose or recommend other treatments.
What are the common side effects of hydralazine/isosorbide dinitrate?
The registry lists Headache, Dizziness among the most-reported FAERS reaction terms for hydralazine/isosorbide dinitrate. The compiled record contains 17,561 FDA adverse-event reports. These counts are not an individual symptom assessment.
Does hydralazine/isosorbide dinitrate interact with other medications?
The registry has 2 documented interaction rows for hydralazine/isosorbide dinitrate. Notable source-record pairings include sildenafil, tadalafil. These rows are not a complete medication review.
What drug class is hydralazine/isosorbide dinitrate?
hydralazine/isosorbide dinitrate belongs to the Vasodilator / Nitrate Combination drug class. It requires a prescription (Rx). BiDil is used to treat heart failure in self-identified Black patients.
What pregnancy or breastfeeding source fields are listed for hydralazine/isosorbide dinitrate?
The FDA label for hydralazine/isosorbide dinitrate contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.

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What the FDA Data Shows for hydralazine/isosorbide dinitrate

The FDA label for hydralazine/isosorbide dinitrate (sold under brand names such as BiDil) classifies it as a prescription-only medication in the Vasodilator / Nitrate Combination class. BiDil is used to treat heart failure in self-identified Black patients. Official labeling lists 2 commonly reported side effects, including Headache, Dizziness.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 17,561 voluntary reports. The database also lists 2 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS.

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, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

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. This registry does not provide medication decisions.

Last updated: November 30, 2025

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

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 from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page