Hydralazine Hydrochloride
FDA Drug Information • Also known as: Hydralazine, Hydralazine Hydrochloride
- Brand Names
- Hydralazine, Hydralazine Hydrochloride
- Route
- ORAL
- Dosage Form
- TABLET
- Product Type
- HUMAN PRESCRIPTION DRUG
Description
DESCRIPTION: Rx only Hydralazine Hydrochloride Injection, USP is an antihypertensive available in a 2 mL vial for intravenous and intramuscular administration. Each mL of the sterile, nonpyrogenic colorless solution contains hydralazine hydrochloride USP, 20 mg; methylparaben NF, 0.65 mg; propylparaben NF, 0.35 mg; propylene glycol USP, 103.6 mg, and Water for Injection USP q.s. The pH of the solution is 3.4 to 4.4. pH may be adjusted with hydrochloric acid and/or sodium hydroxide. Hydralazine hydrochloride is 1-hydrazinophthalazine monohydrochloride, and its structural formula is: Hydralazine hydrochloride USP is a white to off-white, odorless crystalline powder. It is soluble in water, slightly soluble in alcohol, and very slightly soluble in ether. It melts at about 275°C, with decomposition. structure
What Is Hydralazine Hydrochloride Used For?
INDICATIONS AND USAGE: Severe essential hypertension when the drug cannot be given orally or when there is an urgent need to lower blood pressure.
Dosage and Administration
Dosage and Administration When there is urgent need, therapy in the hospitalized patient may be initiated intramuscularly or as a rapid intravenous bolus injection directly into the vein. Hydralazine Hydrochloride Injection should be used only when the drug cannot be given orally. The usual dose is 20-40 mg, repeated as necessary. Certain patients (especially those with marked renal damage) may require a lower dose. Blood pressure should be checked frequently. It may begin to fall within a few minutes after injection, with the average maximal decrease occurring in 10-80 minutes. In cases where there has been increased intracranial pressure, lowering the blood pressure may increase cerebral ischemia. Most patients can be transferred to oral hydralazine hydrochloride within 24-48 hours. The product should be used immediately after the vial is opened. The product should not be added to infusion solutions. Hydralazine Hydrochloride Injection may discolor upon contact with metal; discolored solutions should be discarded. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Side Effects (Adverse Reactions)
ADVERSE REACTIONS: To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Kabi USA, LLC at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. Adverse reactions with hydralazine hydrochloride are usually reversible when dosage is reduced. However, in some cases it may be necessary to discontinue the drug. The following adverse reactions have been observed, but there has not been enough systematic collection of data to support an estimate of their frequency. Common: Headache, anorexia, nausea, vomiting, diarrhea, palpitations, tachycardia, angina pectoris. Less Frequent: Digestive -constipation, paralytic ileus. Cardiovascular - hypotension, paradoxical pressor response, edema. Respiratory - dyspnea. Neurologic - peripheral neuritis, evidenced by paresthesia, numbness, and tingling; dizziness; tremors; muscle cramps, psychotic reactions characterized by depression, disorientation, or anxiety. Genitourinary - difficulty in urination. Hematologic - blood dyscrasias, consisting of reduction in hemoglobin and red cell count, leukopenia, agranulocytosis, purpura; lymphadenopathy; splenomegaly. Hypersensitive Reactions - rash, urticaria, pruritis, fever, chills, arthralgia, eosinophilia, and, rarely, hepatitis. Other - nasal congestion, flushing, lacrimation, conjunctivitis.
Warnings and Precautions
WARNINGS: In a few patients, hydralazine may produce a clinical picture simulating systemic lupus erythematosus including glomerulonephritis. In such patients, hydralazine should be discontinued unless the benefit-to-risk determination requires continued antihypertensive therapy with this drug. Symptoms and signs usually regress when the drug is discontinued but residua have been detected many years later. Long-term treatment with steroids may be necessary (see PRECAUTIONS , Laboratory Tests ).
Contraindications
CONTRAINDICATIONS: Hypersensitivity to hydralazine, coronary artery disease, mitral valvular rheumatic heart disease.
Overdosage
OVERDOSAGE: Acute Toxicity No deaths due to acute poisoning have been reported. Highest known dose survived: adults, 10 g orally. Oral LD 50 in rats: 173 and 187 mg/kg. Signs and Symptoms Signs and symptoms of overdosage include hypotension, tachycardia, headache, and generalized skin flushing. Complications can include myocardial ischemia and subsequent myocardial infarction, cardiac arrhythmia, and profound shock. Treatment There is no specific antidote. Support of the cardiovascular system is of primary importance. Shock should be treated with plasma expanders. If possible, vasopressors should not be given, but if a vasopressor is required, care should be taken not to precipitate or aggravate cardiac arrhythmia. Tachycardia responds to beta blockers. Digitalization may be necessary, and renal function should be monitored and supported as required. No experience has been reported with extracorporeal or peritoneal dialysis. Acute Toxicity No deaths due to acute poisoning have been reported. Highest known dose survived: adults, 10 g orally. Oral LD 50 in rats: 173 and 187 mg/kg. Signs and Symptoms Signs and symptoms of overdosage include hypotension, tachycardia, headache, and generalized skin flushing. Complications can include myocardial ischemia and subsequent myocardial infarction, cardiac arrhythmia, and profound shock. Treatment There is no specific antidote. Support of the cardiovascular system is of primary importance. Shock should be treated with plasma expanders. If possible, vasopressors should not be given, but if a vasopressor is required, care should be taken not to precipitate or aggravate cardiac arrhythmia. Tachycardia responds to beta blockers. Digitalization may be necessary, and renal function should be monitored and supported as required. No experience has been reported with extracorporeal or peritoneal dialysis.
How Supplied
How Supplied Strength Unit of Sale 20 mg per mL, 1 mL fill / 2mL Single Dose Vial Overbagged with 5 x 1 mL Single Dose Vial in each bag, NDC 55154-9554-5 WARNING: This Unit Dose package is not child resistant and is Intended for Institutional Use Only. Keep this and all drugs out of the reach of children. The container closure is not made with natural rubber latex. Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.