Injection is indicated for short-term use in the emergency reduction of blood pressure in severe, nonmalignant and malignant hypertension in hospitalized adults; and in acute severe hypertension in hospitalized children, when prompt and urgent decrease of diastolic pressure is required.
Treatment with orally effective antihypertensive agents should not be instituted until blood pressure has stabilized.
The use of HYPERSTAT I.V.
Injection for longer than 10 days is not recommended.HYPERSTAT I.V.Injection is ineffective against hypertension due to pheochromocytoma.
HYPERSTAT I.V.Injection should not be used in the treatment of compensatory hypertension, such as that associated with aortic coarctation or arteriovenous shunt, and should not be used in patients hypersensitive to diazoxide, other thiazides, or other sulfonamide-derived drugs.
Caution must be observed when reducing severely elevated blood pressure.
Diazoxide should only be administered utilizing the new 150-mg minibolus dosage.
The use of a 300-mg intravenous dose of diazoxide has been associated with angina and with myocardial and cerebral infarction.
One instance of optic nerve infarction was reported when a 100-mmHg reduction in diastolic pressure occurred over ten minutes following a single 300-mg bolus.
In one prospective trial conducted in patients with severe hypertension and coexistent coronary artery disease, a 50% incidence of ischemic changes in the electrocardiogram was observed following single 300-mg bolus injections of diazoxide.
The desired blood pressure lowering should therefore be achieved over as long a period of time as is compatible with the patient's status.
At least several hours and preferably 1 or 2 days is tentatively recommended.Improved safety with equal efficacy can be achieved by administering HYPERSTAT I.V.
Injection as a minibolus dose (1 to 3 mg/kg every 5 to 15 minutes up to a maximum of 150 mg in a single injection) until a diastolic blood pressure below 100 mmHg is achieved.
Injection should not be administered in a bolus dose of 300 mg since this mode of administration is less predictable and less controllable than the minibolus dosage.
If hypotension severe enough to require therapy results from the reduction in blood pressure, it will usually respond to the Trendelenberg maneuver.If necessary, sympathomimetic agents such as dopamine or norepinephrine may be administered.Special attention is required for patients with diabetes mellitus and those in whom retention of salt and water may present serious problems.