Reactions 1371 - 1 Oct 2011

STheophylline

Tonic-clonic seizures in an elderly patient: casereport

A 76-year-old woman developed tonic-clonic seizuresduring treatment with theophylline for chronic obstructivepulmonary disease, and after smoking cessation.

The woman presented with malaise and a 2-days historyof dizziness. Her medications included theophylline MR175mg twice daily [route and duration of treatment toreaction onset not stated]. After smoking 100 cigarettesdaily for 40 years, she had given up smoking 2 weeksearlier. Laboratory findings on admission showed a serumpotassium level of 3.0 mmol/L.

The woman was started on trimethoprim for a suspectedurinary tract infection. Two days later, she developed facialspasms and muscle twitching of her upper lip. Sheexperienced two tonic-clonic seizures over the following2 hours, which resolved with lorazepam treatment. Thefollowing day, she experienced two further tonic-clonicseizures. Further investigations showed a theophyllineconcentration of 41.6 µg/mL. Theophylline was withdrawn,and her neurological symptoms improved dramatically.Her theophylline concentration had returned to a safe levelwithin 3 days. She died 2 weeks later from sepsis.

Author comment: "The cytochrome P450 enzyme CYP1A2mediates the rate-limiting step in the metabolism ofTheophylline, and the polycyclic aromatic hydrocarbonsfound in cigarette smoke are potent inducers of this enzyme."Altaie N, et al. Theophylline toxicity - A forgotten entity. British Journal ofMedical Practitioners 4: a404, No. 1, Mar 2011 - United Kingdom 803060757

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Reactions 1 Oct 2011 No. 13710114-9954/10/1371-0001/$14.95 © 2010 Adis Data Information BV. All rights reserved