Overdose : מינון יתר

4.9       Overdose

Signs and symptoms
In case of acute myocardial infarction , an excessive reduction of aortic pressure bears the risk of a decrease in diastolic corona perfusion. In case of acute cardiac failure with decreased filling pressures the cardiac output may continue to drop.


Tachyphylaxis and rebound phenomenon are possible.

Cyanide intoxication may occur during the treatment with Nipruss. This depends on the duration of treatment and the dose level. Short-term treatment with 2.5 μg/kg/min is safe.
By contrast,
•    5 μg/kg/min after 10 hours,
•    10 μg/kg/min after 4 hours and
•    20 μg/kg/min after as early as 1.5 hours

can lead to life-threatening cyanide levels.

Treatment:
Therapeutic countermeasures include reducing the infusion dose or administering an antidote.


In case of cyanide intoxication, 4-dimethyl-aminophenol-hydrochloride (4-DMAP) 3 to 4 mg/kg IV (produces methaemoglobin) is recommended as a short-acting antidote. This is followed by an infusion of sodium thiosulfate, 50-100 mg/kg BW.
In cases of thiocyanate intoxication, the infusion of sodium nitroprusside should be discontinued and, if necessary, thiocyanate should be removed from the body via dialysis.


For further information, see also sections 4.2 and 4.4.