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-Kranit', 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the prolonged shelf stability and pharmacological potency of some pharmaceuticals and points to the risk of long-outdated prescriptions. Physicians should primarily not underestimate drug toxicity in consequence of old-age pharmaceuticals.