Medical toxicology
-
This review examines the various clinical options used to elicit gastric emptying, viz. drug-induced emesis, mechanical pharyngeal stimulation, gastric lavage, and catharsis. Apomorphine and syrup of ipecac are the 2 drugs most frequently used for induction of emesis. Both agents act centrally and, in addition, syrup of ipecac has a peripheral action. ⋯ They elicit an osmotic reaction in the small intestine which results in increased intraluminal fluid bulk, hyperperistalsis, and subsequent propulsion of contents. Cathartics have also been shown to stimulate the secretion of cholecystokinin, which is thought to have similar effects on the intestine. Cathartics have not been shown to significantly enhance drug elimination from the gastrointestinal tract.(ABSTRACT TRUNCATED AT 400 WORDS)
-
Deaths from tricyclic antidepressant (TCA) overdose are usually due to arrhythmias and/or hypotension. Tricyclic antidepressant toxicity is due mainly to the quinidine-like actions of these drugs on cardiac tissues. Slowing of phase 0 depolarisation of the action potential results in slowing of conduction through the His-Purkinje system and myocardium. ⋯ However, administration of hypertonic sodium bicarbonate is beneficial even when blood pH is normal. Lignocaine (lidocaine) may be useful in treating ventricular tachycardia but should be administered cautiously to avoid precipitating seizures. Ventricular bradyarrhythmias are due to impaired automaticity or depressed atrioventricular conduction and can be treated by placement of a temporary pacemaker, or with a chronotropic agent, e.g. isoprenaline (isoproterenol), with or without concomitant vasoconstrictors.(ABSTRACT TRUNCATED AT 400 WORDS)