BiDil Hydralazine hydrochloride and Isosorbide dinitrate 37.5 mg; 20 mg Tablet, Film Coated, 90-count
🆔 Identity & classification
Where does this data come from?
🏷️ RxNorm drug class
This medicine belongs to the Arteriolar Vasodilator class.
Where does this data come from?
🏭 Manufacturer & labeler
Where does this data come from?
🩺 Clinical
Hydralazine is used to treat high blood pressure. Hydralazine is in a class of medications called vasodilators. It works by relaxing the blood vessels so that blood can flow more easily through the body. High blood pressure is a common condition and when not treated, can cause damage to the brain, heart, blood vessels, kidneys and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressur...
Read the full MedlinePlus article ↗- That's a really common question. This combination was studied specifically in self-identified Black patients with heart failure, and the clinical trial — called A-HeFT — showed cle...
- Why is this medication specifically for Black patients? Can anyone else take it?
- Yes, headache is actually the most common side effect, and it's the main reason some people stop taking this medication. The good news is that headaches often improve as your body...
- I get terrible headaches — is that from this medication, and will they go away?
Patient education
Supplement & herbal interactions
Where does this data come from?
Ask a licensed pharmacist directly — free, answered by our team.
💊 What it looks like
Where does this data come from?
🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
-
UNII LMI26O6933
Alumina is a white powder form of aluminum oxide. It's used as a filler to add bulk to tablets and capsules, and sometimes as a thickening or anti-caking agent in powdered formulations.
-
UNII 3SY5LH9PMK
Anhydrous lactose is a milk sugar with no water content. It acts as a filler and binder in tablets and capsules, adding bulk and helping ingredients stick together.
-
UNII H77VEI93A8
A synthetic yellow dye used to color medications. It helps identify the drug and make it visually distinctive, with no effect on how the medicine works.
-
UNII 3NXW29V3WO
Hypromellose is a plant-based thickener made from cellulose. It's used in medicines as a binder to hold ingredients together, a coating for tablets, and a thickener for liquids.
-
UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
-
UNII OP1R32D61U
Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
-
UNII 3WJQ0SDW1A
Polyethylene glycol is a synthetic liquid or solid polymer used in medicines as a solvent, lubricant, and humectant. It helps dissolve active ingredients, reduces friction during manufacturing, and retains moisture in the final product.
-
UNII 6OZP39ZG8H
Polysorbate 80 is a synthetic emulsifier derived from sorbitol and oleic acid. It helps mix oil and water-based ingredients together in medications and improves how the product disperses in the body.
-
UNII ETJ7Z6XBU4
Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
-
UNII 5856J3G2A2
A starch-based powder made from potatoes and processed with sodium. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the medicine can be absorbed.
-
UNII 15FIX9V2JP
Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.
11 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
Are inactive ingredients the same for every manufacturer?
Why might an inactive ingredient be missing?
Can inactive ingredients matter?
💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $4.345 | $391.07 / 90 tablets |
| Medicaid paysCMS SDUD · 12 mo | $4.40 | $395.61 / 90 tablets |
| Medicare drug plans payPart D · Q2 2026 | $4.67 | $420.64 / 90 tablets |
Where does this data come from?
🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| isosorbide dinitrate and hydralazine hydrochloride 37.5 mg/1; 20 mg 52536-0006-09 | Wilshire | 90 tablets | $0.709 | AB | Availability likely | save 84% |
| isosorbide dinitrate and hydralazine hydrochloride 20 mg/1; 37.5 mg 72319-0012-03 | i3 | 90 tablets | $0.709 | AB | Availability likely | save 84% |
| Isosorbide dinitrate and hydralazine hydrochloride 37.5 mg/1; 20 mg 50742-0246-18 | Ingenus | 180 tablets | $1.576 | AB | FDA listed | save 64% |
| BiDil 37.5 mg/1; 20 mgthis 24338-0010-09 | Azurity | 90 tablets | $4.345 | AB | Availability likely | — |
| isosorbide dinitrate and hydralazine hydrochloride 37.5 mg/1; 20 mg 72162-2343-09 | Bryant | 90 tablets | — | AB | FDA listed | — |
| isosorbide dinitrate and hydralazine hydrochloride 20 mg/1; 37.5 mg 73141-0012-03 | A2A | 90 tablets | — | AB | FDA listed | — |
Where does this data come from?
⏳ Availability & generic status
The FDA lists approved generic versions of this medicine, but that does not always mean a pharmacy can get one today. Patent rules, launch agreements, supply and pricing can affect when generics actually arrive.
Where does this data come from?
🗺️ Medicaid utilization & spend
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 24338-0010-09 You're viewing this | 90 TABLET, FILM COATED in 1 BOTTLE (24338-010-09) | 2020-08-31 | Active |
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
1 INDICATIONS AND USAGE BiDil is a combination of isosorbide dinitrate, a nitrate vasodilator, and hydralazine hydrochloride, an arteriolar vasodilator, indicated for: the treatment of heart failure as an adjunct therapy to standard therapy in self-identified black patients to improve survival, prolong time to hospitalization for heart failure and to improve patient-reported functional status ( 1.1 ) Limitations of use: There is little experience in patients with NYHA class IV heart failure ( 1.2 )
1.1Treatment of Heart Failure in Self-identified Black Patients BiDil is indicated for the treatment of heart failure as an adjunct to standard therapy in self-identified black patients to improve survival, to prolong time to hospitalization for heart failure, and to improve patient-reported functional status.
1.2Limitations of Use There is little experience in patients with NYHA class IV heart failure.
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION BiDil should be initiated at a dose of one BiDil Tablet, three times a day. Titrate to a maximum of two tablets three times daily, if tolerated. Although titration of BiDil can be rapid (3-5 days), some patients may experience side effects and may take longer to reach their maximum tolerated dose.
The dosage may be decreased to as little as one-half BiDil Tablet three times a day if intolerable side effects occur. Efforts should be made to titrate up as soon as side effects subside. One tablet three times a day titrated to a maximum tolerated dose up to two tablets three times a day ( 2 ) Dosage may be decreased to as little as one-half tablet three times a day if intolerable side effects occur.
Efforts should be made to titrate up as soon as side effects subside ( 2 )
💊 Dosage Forms and Strengths ▾
3 DOSAGE FORMS AND STRENGTHS The BiDil (20 mg isosorbide dinitrate and 37.5 mg hydralazine hydrochloride) tablets are orange, biconvex, approximately 8 mm in diameter, scored, film-coated, and debossed with "20" on one side over the score and " N " on the other side. Tablets (scored): 20 mg isosorbide dinitrate and 37.5 mg hydralazine hydrochloride ( 3 )
⛔ Contraindications ▾
4 CONTRAINDICATIONS BiDil is contraindicated in patients who are allergic to organic nitrates. Do not use BiDil in patients who are taking PDE-5 inhibitors, such as avanafil, sildenafil, tadalafil, or vardenafil. Concomitant use can cause severe hypotension, syncope, or myocardial ischemia [see Drug Interactions (7.1) ] .
Do not use BiDil in patients who are taking the soluble guanylate cyclase (sGC) stimulator riociguat. Concomitant use can cause hypotension. Patients who are allergic to organic nitrates ( 4 ) Use of phosphodiesterase type 5 (PDE5) inhibitors, such as avanafil, sildenafil, tadalafil, or vardenafil, or soluble guanylate cyclase (sGC) stimulator (riociguat).
( 4 )
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS May cause symptomatic hypotension ( 5.1 ) Symptomatic Lupus Erythematosus Syndromes: Consider discontinuation if clinically appropriate ( 5.2 ) Myocardial ischemia and angina ( 5.3 ) Peripheral Neuritis : May be treated with Pyridoxine ( 5.4 )
5.1Hypotension Symptomatic hypotension, particularly with upright posture, may occur with even small doses of BiDil. Hypotension is most likely to occur in patients who have been volume or salt depleted; correct prior to initiation of BiDil [see Adverse Reactions (6.1) ] .
5.2Systemic Lupus Erythematosus Hydralazine hydrochloride has been reported to cause a drug-induced systemic lupus erythematosus (SLE) syndrome. Symptoms and signs usually regress when hydralazine hydrochloride is discontinued.
5.3Worsening Ischemic Heart Disease Hydralazine hydrochloride can cause tachycardia and hypotension potentially leading to myocardial ischemia and angina, particularly in patients with hypertrophic cardiomyopathy.
5.4Peripheral Neuritis Hydralazine hydrochloride has been associated with peripheral neuritis, evidenced by paresthesia, numbness, and tingling, which may be related to an antipyridoxine effect. Pyridoxine should be added to BiDil therapy if such symptoms develop.
🤒 Adverse Reactions ▾
6 ADVERSE REACTIONS Most common adverse reactions (≥ 5% more on BiDil than on placebo) were headache and dizziness ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Azurity Pharmaceuticals, Inc. at 1-800-461-7449 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .
6.1Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. BiDil has been evaluated for safety in 517 heart failure patients in A-HeFT. A total of 317 of these patients received BiDil for at least 6 months, and 220 received BiDil for at least 12 months.
In A-HeFT, 21% of the patients discontinued BiDil for adverse reactions compared to 12% who discontinued placebo. Overall, adverse reactions were more common in BiDil -treated than in placebo-treated patients. Table 1 lists adverse reactions reported with an incidence, after rounding, ≥ 2% higher on BiDil than on placebo in A-HeFT, regardless of causality.
The most common reasons for discontinuing BiDil in the A-HeFT trial was headache (7%). Table 1. Adverse Reactions Occurring in the A-HeFT Study in ≥ 2% of Patients Treated with BiDil.
BiDil (N=517) % Placebo (N=527) % Headache 50 21 Dizziness 32 14 Asthenia 14 11 Nausea 10 6 Hypotension 8 4 Sinusitis 4 2 Ventricular tachycardia 4 2 Paresthesia 4 2 Vomiting 4 2 Amblyopia 3 1 In the V-HeFT I and II clinical studies, a total of 587 patients with heart failure were treated with the combination of isosorbide dinitrate and hydralazine hydrochloride. The type, pattern, frequency and severity of adverse reactions reported in these studies were similar to those reported in A-HeFT, described above and no unusual adverse reactions were reported.
6.2Postmarketing Experience The following adverse reactions have been identified during post-approval use of BiDil. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Use of BiDil: The following adverse reactions have been identified with use of BiDil.
Cardiac Disorders: Palpitations Ear and labyrinth disorders: Tinnitus, vertigo Eye Disorders: Eyelid edema, vision blurred Gastrointestinal Disorders: Abdominal discomfort, constipation General Disorders and Administration Site Conditions: Facial pain, flushing, chest discomfort, chest pain, peripheral edema Musculoskeletal and Connective Tissue Disorders: Pain in extremity, myalgia Nervous Disorders: Dysgeusia, hypoaesthesia, migraine, syncope Renal and Urinary Disorders: Chromaturia, pulmonary renal syndrome Respiratory, Thoracic and Mediastinal Disorders: Dyspnea Reproductive System and Breast Disorders: Erectile dysfunction Skin and Subcutaneous Tissue Disorders: Erythema, hyperhidrosis, pruritus, face swelling Use of Hydralazine Hydrochloride or Isosorbide Dinitrate: The following reactions have been reported with use of either hydralazine hydrochloride or isosorbide dinitrate.
Blood and Lymphatic System Disorders: Blood dyscrasias, agranulocytosis, purpura, eosinophilia, splenomegaly. Eye Disorders: Lacrimation, conjunctivitis. Gastrointestinal Disorders: Paralytic ileus.
Hepatobiliary Disorders: Hepatitis. Psychiatric Disorders: Psychotic reactions, disorientation. Renal and Urinary Disorders: Difficulty in urination.
🔄 Drug Interactions ▾
7 DRUG INTERACTIONS
7.1Phosphodiesterase 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. Do not use BiDil in patients who are taking the soluble guanylate cyclase (sGC) stimulator riociguat. Concomitant use can cause hypotension [see Contraindications (4) ] .
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS Geriatric Use: Isosorbide dinitrate and hydralazine may be eliminated more slowly in elderly patients. Initiate therapy at the low end of the dosing range ( 8.5 )
8.1Pregnancy Risk Summary There are no data on BiDil use in pregnant women, and insufficient data on its components (hydralazine and isosorbide dinitrate) to assess a drug-associated risk of major birth defects or miscarriage with first trimester use. Available published data on hydralazine use in pregnancy during the second and third trimesters have not shown an association with adverse pregnancy-related outcomes. Hydralazine hydrochloride is teratogenic in mice at 66 mg/kg and possibly in rabbits at 33 mg/kg (2 and 3 times the MRHD of BiDil on a body surface area basis).
Isosorbide dinitrate has been shown to cause a dose-related increase in embryo-toxicity (excess mummified pups) in rabbits at 70 mg/kg (12 times the MRHD of BiDil on a body surface area basis). All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnant women with heart failure are at increased risk for preterm birth. Clinical classification of heart disease may worsen with pregnancy and lead to maternal death and/or stillbirth.
8.2Lactation Risk Summary There are no data on the presence of BIDIL in human or animal milk, the effects on the breastfed infant or on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for BIDIL and any potential adverse effects on the breastfed child from BIDIL or from the underlying maternal condition.
8.4Pediatric Use The safety and effectiveness of BiDil in children have not been established.
8.5Geriatric Use Clinical studies of BiDil did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in response between elderly and younger patients. In general, dose selection for an elderly patient should start at the low end of the dosing range, reflecting the greater frequency of decreased hepatic and renal function, and of concomitant disease or other drug therapies.
Isosorbide dinitrate, its active metabolites, and hydralazine may be eliminated more slowly in elderly patients.
8.6Renal Impairment There are no studies of renal impairment using BiDil. No dose adjustment is required for hydralazine or isosorbide dinitrite [see Clinical Pharmacology (12.3) ] . Dialyzability of hydralazine has not been determined . Dialysis is not an effective method for removing isosorbide dinitrate or its metabolite isosorbide-5-mononitrate from the body.
8.7Hepatic Impairment The effect of hepatic impairment on the pharmacokinetics of hydralazine alone has not been determined.Isosorbide dinitrate concentrations increase in patients with cirrhosis. There are no studies of hepatic impairment using BiDil.
🤰 Pregnancy ▾
8.1Pregnancy Risk Summary There are no data on BiDil use in pregnant women, and insufficient data on its components (hydralazine and isosorbide dinitrate) to assess a drug-associated risk of major birth defects or miscarriage with first trimester use. Available published data on hydralazine use in pregnancy during the second and third trimesters have not shown an association with adverse pregnancy-related outcomes. Hydralazine hydrochloride is teratogenic in mice at 66 mg/kg and possibly in rabbits at 33 mg/kg (2 and 3 times the MRHD of BiDil on a body surface area basis).
Isosorbide dinitrate has been shown to cause a dose-related increase in embryo-toxicity (excess mummified pups) in rabbits at 70 mg/kg (12 times the MRHD of BiDil on a body surface area basis). All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnant women with heart failure are at increased risk for preterm birth. Clinical classification of heart disease may worsen with pregnancy and lead to maternal death and/or stillbirth.
🧒 Pediatric Use ▾
8.4Pediatric Use The safety and effectiveness of BiDil in children have not been established.
🧓 Geriatric Use ▾
8.5Geriatric Use Clinical studies of BiDil did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in response between elderly and younger patients. In general, dose selection for an elderly patient should start at the low end of the dosing range, reflecting the greater frequency of decreased hepatic and renal function, and of concomitant disease or other drug therapies.
Isosorbide dinitrate, its active metabolites, and hydralazine may be eliminated more slowly in elderly patients.
🆘 Overdosage ▾
10 OVERDOSAGE The signs and symptoms of overdosage with BiDil are expected to be those of excessive pharmacologic effect, i.e., vasodilatation, reduced cardiac output and hypotension, and signs and symptoms include headache, confusion, tachycardia, and generalized skin flushing. Complications can include myocardial ischemia and subsequent myocardial infarction, cardiac arrhythmia, and profound shock. Syncope, coma and death may ensue without appropriate treatment.
Human Experience: There are no documented cases of overdosage with BiDil. No deaths from acute poisoning have been reported. Treatment: There is no specific antidote.
Support of the cardiovascular system is of primary importance. Shock should be treated with plasma expanders, vasopressors, and positive inotropic agents. The gastric contents should be evacuated, taking adequate precautions to prevent aspiration.
These manipulations have to be carried out after cardiovascular status has been stabilized, since they might precipitate cardiac arrhythmias or increase the depth of shock. In patients with renal disease or congestive heart failure, therapy resulting in central volume expansion is not without hazard. Treatment of isosorbide dinitrate overdose in these patients may be difficult, and invasive monitoring may be required.
No data are available to suggest physiological maneuvers (e.g., maneuvers to change the pH of the urine) that might accelerate elimination of the components of BiDil. Dialysis is not effective in removing circulating isosorbide dinitrate. The dialyzability of hydralazine has not been determined.
Methemoglobinemia: Nitrate ions liberated during metabolism of isosorbide dinitrate can oxidize hemoglobin into methemoglobin. There are case reports of significant methemoglobinemia in association with moderate overdoses of organic nitrates. Methemoglobin levels are measurable by most clinical laboratories.
Methemoglobinemia could be serious in chronic heart failure patients because of already compromised vascular bed-tissue gas exchange dynamics. Classically, methemoglobinemic blood is described as chocolate brown, without color change on exposure to air. When methemoglobinemia is diagnosed, the treatment of choice is methylene blue, 1 to 2 mg/kg intravenously.
🧬 Clinical Pharmacology ▾
12 CLINICAL PHARMACOLOGY
12.1Mechanism of Action The mechanism of action underlying the beneficial effects of BiDil in the treatment of heart failure has not been established. Isosorbide dinitrate is a vasodilator affecting both arteries and veins. Its dilator properties result from the release of nitric oxide and the subsequent activation of guanylyl cyclase, and ultimate relaxation of vascular smooth muscle.
Several well-controlled clinical trials have used exercise testing to assess the anti-anginal efficacy of chronically-delivered nitrates. In the large majority of these trials, active agents were no more effective than placebo after 24 hours (or less) of continuous therapy. Attempts to overcome nitrate tolerance by dose escalation, even to doses far in excess of those used acutely, have consistently failed.
Only after nitrates have been absent from the body for several hours is response to nitrates restored. Hydralazine hydrochloride is a selective dilator of arterial smooth muscle. Animal data suggests that hydralazine may also mitigate tolerance to nitrates.
12.2Pharmacodynamics The basis for the beneficial clinical effects of BiDil is not known. In a small study of patients with chronic heart failure administered single doses of hydralazine 75 mg, isosorbide dinitrate 20 mg, and the combination, the combination elicited a statistically significant decrease in pulmonary capillary wedge pressure compared to hydralazine alone. The increase in cardiac output, renal blood flow and limb blood flow with the combination, however, was not greater than with hydralazine alone.
There is no study of hemodynamic effects following multiple dosing.
12.3Pharmacokinetics Absorption BiDil: Following a single 75-mg oral dose of hydralazine plus 40 mg of isosorbide dinitrate to 19 healthy adults, peak plasma concentrations of hydralazine (88 ng/mL/65 kg) and isosorbide dinitrate (76 ng/mL/65 kg) were reached in 1 hour. The half-lives were about 4 hours for hydralazine and about 2 hours for isosorbide dinitrate. Peak plasma concentrations of the two active metabolites, isosorbide-2-mononitrate and isosorbide-5-mononitrate, were 98 and 364 ng/mL/65 kg, respectively, at about 2 hours.
No information is currently available regarding the effect of food on the bioavailability of hydralazine or isosorbide dinitrate from BiDil tablets. Hydralazine hydrochloride: About 2/3 of a 50-mg dose of 14 C-hydralazine hydrochloride given in gelatin capsules was absorbed in hypertensive subjects. In patients with heart failure, mean absolute bioavailability of a single oral dose of hydralazine 75 mg varies from 10 to 26%, with the higher percentages in slow acetylators.
Administration of doses escalating from 75 mg to 1000 mg three times daily to congestive heart failure patients resulted in an up to 9-fold increase in the dose normalized AUC, indicating non-linear kinetics of hydralazine, probably reflecting saturable first pass metabolism. Isosorbide dinitrate: Absorption of isosorbide dinitrate from tablets after oral dosing is nearly complete. The average bioavailability of isosorbide dinitrate is about 25%, but is highly variable (10%-90%) because of first-pass metabolism, and increases progressively during chronic therapy.
Serum concentrations reach their maximum about one hour after ingestion. Distribution Hydralazine hydrochloride: After intravenous administration of hydralazine in a dose of 0.3 mg/kg, the steady-state volume of distribution in patients with congestive heart failure was
2.2L/kg. Isosorbide dinitrate: The volume of distribution of isosorbide dinitrate is 2 to 4 L/kg. About 28% of circulating isosorbide dinitrate is protein bound.
Under steady-state conditions, isosorbide dinitrate accumulates significantly in muscle (pectoral) and vein (saphenous) wall relative to simultaneous plasma concentrations. Metabolism Hydralazine is metabolized by acetylation, ring oxidation and conjugation with endogenous compounds including pyruvic acid…
🧬 Mechanism of Action ▾
12.1Mechanism of Action The mechanism of action underlying the beneficial effects of BiDil in the treatment of heart failure has not been established. Isosorbide dinitrate is a vasodilator affecting both arteries and veins. Its dilator properties result from the release of nitric oxide and the subsequent activation of guanylyl cyclase, and ultimate relaxation of vascular smooth muscle.
Several well-controlled clinical trials have used exercise testing to assess the anti-anginal efficacy of chronically-delivered nitrates. In the large majority of these trials, active agents were no more effective than placebo after 24 hours (or less) of continuous therapy. Attempts to overcome nitrate tolerance by dose escalation, even to doses far in excess of those used acutely, have consistently failed.
Only after nitrates have been absent from the body for several hours is response to nitrates restored. Hydralazine hydrochloride is a selective dilator of arterial smooth muscle. Animal data suggests that hydralazine may also mitigate tolerance to nitrates.
📦 How Supplied / Storage and Handling ▾
16 HOW SUPPLIED/STORAGE AND HANDLING BiDil Tablets contain 20 mg of isosorbide dinitrate and 37.5 mg of hydralazine hydrochloride. They are biconvex, approximately 8 mm in diameter, scored, film-coated, orange tablets debossed "20" on one side over the score and " N " on the other side. NDC 24338-010-09: Bottles of 90 Store at 25°C (77°F), excursions permitted to 15-30°C (59-86°F). [See USP Controlled Room Temperature.] Keep bottles tightly closed.
Protect from light. Dispense in a light-resistant, tight container.
📋 Description ▾
11 DESCRIPTION BiDil is a fixed-dose combination of isosorbide dinitrate, a vasodilator with effects on both arteries and veins, and hydralazine hydrochloride, a predominantly arterial vasodilator. Isosorbide dinitrate is described chemically as 1,4:3,6-dianhydro-D-glucitol dinitrate and its structural formula is: Isosorbide dinitrate is a white to off-white, crystalline powder with the empirical formula C 6 H 8 N 2 O 8 and a molecular weight of 236.14. It is freely soluble in organic solvents such as alcohol, chloroform and ether, but is only sparingly soluble in water.
Hydralazine hydrochloride is described chemically as 1-hydrazinophthalazine monohydrochloride, and its structural formula is: Hydralazine hydrochloride is a white to off-white, crystalline powder with the empirical formula C 8 H 8 N 4 ∙HCl and a molecular weight of 196.64. It is soluble in water, slightly soluble in alcohol, and very slightly soluble in ether. Each BiDil Tablet for oral administration contains 20 mg of isosorbide dinitrate and 37.5 mg of hydralazine hydrochloride.
The inactive ingredients in BiDil tablets include: anhydrous lactose, microcrystalline cellulose, sodium starch glycolate, colloidal silicon dioxide, magnesium stearate, hypromellose, FD&C Yellow No. 6 aluminum lake, polyethylene glycol, titanium dioxide, polysorbate 80. structure1 structure2
💬 Information for Patients ▾
17 PATIENT COUNSELING INFORMATION Patients should be informed of possible side effects and advised to take the medication regularly and continuously as directed. Headache Inform patients that headaches often accompany treatment with BiDil, especially during initiation of treatment. Advise patients to consult a physician to adjust the dose of BiDil if headache continues with repeated dosing.
Hypotension Warn patients about lightheadedness on standing. Advise patients that inadequate fluid intake or excessive fluid loss from perspiration, diarrhea or vomiting may lead to an excessive fall in blood pressure and cause lightheadedness or even syncope. If syncope does occur, advise patients to discontinue BiDil and notify their prescribing physician as soon as possible.
Phosphodiesterase-5 Inhibitors Advise patients to inform their physicians if they are taking, or planning to take, sildenafil, vardenafil, or tadalafil. Bidil should not be taken concomitantly with phosphodiesterase-5 inhibitors. Worsening Ischemic Heart Disease Advise patients to inform their physicians of any worsening of symptoms of myocardial ischemia, especially those with hypertrophic cardiomyopathy.
Systemic Lupus Erythematosus-like Symptoms Advise patients if symptoms suggestive of systemic lupus erythematosus—such as arthralgia, fever, chest pain, prolonged malaise—occur to notify their prescribing physician. Peripheral Neuritis Advise patients if symptoms of peripheral neuritis—paresthesia, numbness, and tingling—occur to notify the prescribing physician. Manufactured for: Azurity Pharmaceuticals, Inc.
Woburn, MA 01801 USA Manufactured by: Lannett Company, Inc. Philadelphia, PA 19136 BiDil is a registered trademark of Azurity Pharmaceuticals, Inc. © 2025 All rights reserved BDL-PI-07 CIA75474J