[Clinico-pharmacological case (4). Epileptic seizure as an unwanted drug effect on theophylline poisoning].

In spite of the better understanding of the pharmacokinetics and optimized galenics of oral theophylline formulations, therapy with this bronchodilator still bears risks because of its narrow therapeutic window combined with substantial inter- and intra-individual variability of theophylline metabolism. In particular, the comedication with a variety of drugs inhibiting theophylline metabolism requires consideration as a potential source of toxicity. Besides mild, self-limited adverse effects, potentially life-threatening toxic manifestations such as ventricular tachyarrhythmias, shock, and seizures can occur especially with high plasma concentrations. We report the case of a 72-year-old patient with chronic obstructive pulmonary disease who was admitted for surgical treatment of an ulcer of the foot. During combined therapy with theophylline and ciprofloxacin he developed signs of theophylline toxicity with a single episode of partial seizures. These symptoms rapidly improved with repetitive application of activated charcoal and sorbitol. Clinically relevant drug-drug interactions with theophylline and the role and mechanism of action of activated charcoal in intoxicated patients are discussed.