Overdose : מינון יתר

4.9    Overdose
Cases of dobutamine overdose have been reported rarely.

Signs and symptoms
The toxic phenomena of dobutamine are generally due to an overstimulation of the ß-cardiac receptors. The duration of action of dobutamine is generally short (T½ - 2 minutes) due to the rapid metabolization by catechol-O-methyltransferase. Symptoms of toxicity include anorexia, nausea and vomiting, tremors, anxiety, palpitations, headache, dyspnoea, anginal and non-specific chest pains. The positive inotropic and chronotropic effects of dobutamine on myocardial may cause hypertension, tachyarrhythmias, myocardial ischemia and ventricular fibrillation. Hypotension can result in vasodilation.
If the product is ingested orally, any absorption from the oral and intestinal mucosa is unpredictable.

Treatment
The initial action consists in suspending the administration of dobutamine, establishing the patency of the airways and ensuring oxygenation and ventilation. Promptly implement the measures of resuscitation.
The severe ventricular tachyarrhythmia can be successfully treated with propanol or lidocaine.
Hypertension generally responds to dose reduction or discontinuation of therapy.

If necessary, carefully monitor and maintain, within acceptable limits, the vital signs, blood gases, serum electrolytes, etc. Drug absorption by the gastrointestinal tract can be reduced by activated charcoal, which is often more effective than induction of vomit or gastric lavage. Therefore, consider the administration of activated charcoal in addition or instead of gastric lavage. The repeated administration of charcoal can accelerate the elimination of some drugs which have previously been taken.

When performing gastric emptying manoeuvres or activated charcoal administration, check the integrity of the respiratory tract.

Forced diuresis, peritoneal dialysis, hemodialysis, and charcoal hemoperfusion have not been shown to be beneficial in cases of dobutamine overdose.