Acute Toxicity

No deaths due to acute poisoning have been reported.
   Highest known dose survived: adults, 10g orally.
   Oral LD50 in rats: 173 and 187 mg/kg.

Signs and Symptoms

Signs and symptoms of overdosage include hypotension, tachycardia, head- ache, and generalized skin flushing.
   Complications can include myocardial ischemia and subsequent myocardial infarction, cardiac arrhythmia, and profound shock.

Treatment

There is no specific antidote.
   The gastric contents should be evacuated, taking adequate precautions against aspiration and for protection of the airway. An activated charcoal slurry may be instilled if conditions permit. These manipulations may have to be omitted or carried out after cardiovascular status has been stabilized, since they might precipitate cardiac arrhythmias or increase the depth of shock.
   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.

Hypersensitivity to hydralazine; coronary artery disease; mitral valvular rheumatic heart disease.

Last reviewed on RxList: 12/8/2004
This monograph has been modified to include the generic and brand name in many instances.