Hydralazine Hydrochloride Injection, USP is indicated for severe essential hypertension when the drug cannot be given orally or when there is an urgent need to lower blood pressure.
According to IQVIA, US sales of Hydralazine Hydrochloride Injection, USP, 20mg/mL, were approximately $51 million in the 12 months ending March 2021.
Hikma is the third largest US supplier of generic injectable medicines by volume, with a growing portfolio of over 100 products. Today one in every six injectable generic medicines used in US hospitals is a Hikma product.
Important Safety Information for Hydralazine Hydrochloride Injection, USP, 20mg/mL:
CONTRAINDICATIONS
Hypersensitivity to hydralazine; coronary artery disease; mitral valvular rheumatic heart disease.
WARNINGS & 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.
- Precautions: myocardial stimulation produced by hydralazine can cause anginal attacks and ECG changes of myocardial ischemia. The drug has been implicated in the production of myocardial infarction. It must, therefore, be used with caution in patients with suspected coronary artery disease.
The “hyperdynamic” circulation caused by hydralazine may accentuate specific cardiovascular inadequacies. For example, hydralazine may increase pulmonary artery pressure in patients with mitral valvular disease. The drug may reduce the pressor responses to epinephrine. Postural hypotension may result from hydralazine but is less common than with ganglionic blocking agents. It should be used with caution in patients with cerebral vascular accidents.
In hypertensive patients with normal kidneys who are treated with hydralazine, there is evidence of increased renal blood flow and a maintenance of glomerular filtration rate. In some instances where control values were below normal, improved renal function has been noted after administration of hydralazine. However, as with any antihypertensive agent, hydralazine should be used with caution in patients with advanced renal damage.
Peripheral neuritis, evidenced by paresthesia, numbness, and tingling, has been observed. Published evidence suggests an antipyridoxine effect, and that pyridoxine should be added to the regimen if symptoms develop.
- Laboratory Tests: complete blood counts and antinuclear antibody titer determinations are indicated before and periodically during prolonged therapy with hydralazine even though the patient is asymptomatic. These studies are also indicated if the patient develops arthralgia, fever, chest pain, continued malaise, or other unexplained signs or symptoms.
A positive antinuclear antibody titer requires that the physician carefully weigh the implications of the test results against the benefits to be derived from antihypertensive therapy with hydralazine hydrochloride.
Blood dyscrasias, consisting of reduction in hemoglobin and red cell count, leukopenia, agranulocytosis, and purpura, have been reported. If such abnormalities develop, therapy should be discontinued.
ADVERSE REACTIONS
Most Common
Headache, anorexia, nausea, vomiting, diarrhea, palpitations, tachycardia, angina pectoris.
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.
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, pruritus, fever, chills, arthralgia, eosinophilia, and, rarely, hepatitis.
Other: nasal congestion, flushing, lacrimation, conjunctivitis.
MONITORING
- Reduction in systolic and diastolic blood pressure; for injection, blood pressure frequently
- CBC and antinuclear antibody titers; at baseline and periodically during prolonged treatment
DRUG INTERACTIONS
MAO inhibitors should be used with caution in patients receiving hydralazine.
When other potent parenteral antihypertensive drugs, such as diazoxide, are used in combination with hydralazine, patients should be continuously observed for several hours for any excessive fall in blood pressure. Profound hypotensive episodes may occur when diazoxide injection and hydralazine injection are used concomitantly.
USE IN SPECIFIC POPULATIONS
Pregnancy
Animal studies indicate that hydralazine is teratogenic in mice at 20 to 30 times the maximum daily human dose of 200 to 300 mg and possibly in rabbits at 10 to 15 times the maximum daily human dose, but that it is nonteratogenic in rats. Teratogenic effects observed were cleft palate and malformations of facial and cranial bones.
There are no adequate and well-controlled studies in pregnant women. Although clinical experience does not include any positive evidence of adverse effects on the human fetus, hydralazine should be used during pregnancy only if the expected benefit justifies the potential risk to the fetus.
Nursing Mothers
Hydralazine has been shown to be excreted in breast milk. Because many drugs are excreted in human milk, caution should be exercised when hydralazine injection is administered to a nursing woman.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established in controlled clinical trials, although there is experience with the use of hydralazine hydrochloride in children. The usual recommended parenteral dosage, administered intramuscularly or intravenously, is 1.7 to 3.5 mg/kg of body weight daily, divided into four to six doses.
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 to 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 to 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 to 48 hours.
The product should be used immediately after the vial is opened. It 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.
OVERDOSAGE
Acute Toxicity
No deaths due to acute poisoning have been reported. Highest known dose survived: adults, 10 g orally. Oral LD50 in rats: 173 and 187 mg/kg.
Signs and Symptoms of Overdosage:
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 of Overdosage:
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.
ENDING INFORMATION
For additional information, please refer to the Package Insert for full prescribing information, available on www.hikma.com.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit http://www.fda.gov/medwatch or call 1-800-FDA-1088.
Manufactured by:
Hikma Pharmaceuticals USA Inc.
Berkeley Heights, NJ 07922 USA