Role of toxicology assessment in poisoning

Diagnosis of acute poisoning is based on history, symptoms, biomedical investigations, toxicological analyses, and sometimes therapeutic tests. Toxicological analytical methods are now widely available. A qualitative or semiquantitative analysis of the parent compound may be adequate for diagnostic assessment. A quantitative analysis is mandatory for kinetic studies. For instance, in ethylene glycol poisoning, analysis of ethylene glycol concentrations is useful for the diagnosis, but glycolate concentrations are more relevant for the evaluation of the severity and prognosis. Groups of symptoms (or toxidromes) may provide diagnostic clues for toxins that are not usually included in routine screening. The management of the poisoned patient is mostly supportive, but toxicological quantitative analyses are mandatory for some treatments, e.g. alkaline diuresis in salicylate poisoning, repeated activated charcoal in theophylline poisoning, haemodialysis, ethanol in ethylene glycol poisoning, or the use of chelating agents.

The pharmacologic stability of 35-year old theophylline

The propensity to preserve and to hoard drugs over the years at home is a well-known phenomenon and offers the possibility for intentional and accidental drug poisoning in man. We report a case of acute theophylline poisoning in an 80-year old women after ingestion of ‘Asthmo-Kranit1 ’, a 35-year old combined preparation containing theophylline and aminopyrine as the main ingredients. The patient developed the typical clinical picture of a symptomatic theophylline poisoning with flush, tremor, tachycardia, hyperventilation, hypotonia, and hyperglycaemia. The clinical course after treatment with beta-blockers was without complications. The determination of theophylline in tablets showed stability of 90% of the labelled amount of the drug 30 years beyond the expiration date. The case illustrates the prolonged shelf stability and pharmacological potency of some pharmaceuticals and points to the risk of longoutdated prescriptions. Physicians should primarily not underestimate drug toxicity in consequence of old-age pharmaceuticals.