Theophylline Seizures: 4 case reports

Case 1: A boy who had suffered from asthma since he was 1 year old , was taking 'Thea-Our' 400mg 12-hour/y. The 12-year-old was diagnosed as having impetigo and was given erythromycin 250mg qid while stiff taking 'Theo-Dur '. After 5 days' erythromycin treatment he had a mild headache. The next day, about 10 hours after his morning 'Theo­Our, he did not feel well and subsequently had a generalised tonic­clonic seizure and then became unconscious. In hospital he was given IV diazepam, phenytoin and phenobarbitone. One hour after his seizures started his serum theophylline level was 21 .3 Itg/ ml (within the previous year this level had been at 10.1 ltg/mil · His condition was readily stabilised and he was discharged the next day on a lower dose of 'Thea-Our' and phenobarbitone. Neither the boy nor his family had a history of seizures.

Case 2: An asthmatic girl, aged 11 years, was receiving maintenance therapy of 'Thea-Our' 300mg tid. p­Adrenergic tablets and spray were taken if required . The girl developed 'influenza', fever and otitis tor which she was prescribed amoxycillin . She vomited once daily for the next 5 days after which her doctor replaced amoxycillin with 'Pediazole' . 'Thea-Our' was concurrently taken throughout. After 2 days "Pediazole ', and about 9.5 hours after her morning 'Theo-Dur' dose, she suffered a tonic-clonic seizure of a few minutes duration. On admission she was found to be agitated and incoheran\. Two hours after the seizure her serum theophylline level was 20.9 J.lg/ml. Her condition was stabJised without difficultly and her daily 'Theo-Dur' dose was consequently reduced. The girl and her family had no history ot seizures.

Case 3: A 6 -year-old who had severe chronic asthma and a nasal allergy was receiving 'Theo-Dur', beclomethasone and 'Rondec' . The girl sustained minor head trauma during play and later that day developed severe headache which resolved with 'Tylenol' and codeine. The next evening she became 'unresponsive' and started staring. On admission her respiration was Shallow and her colour was dusky. She had left-sided seizures, her feft pupil was smaller than the right , both pupils were unresponsive to light and reflexes were absent. An arterial blood sample was taken: pH was 6.96; Pcoz was 115mm Hg; and POz was 503mm Hg. Her serum theophylline level was found to be 22 j,Lg/ml. 30 min after her seizures. She required intubation and manual ventilation . She was given IV diazepam but still had tonic-clonic seizures. More diazepam was given. She was more alert, but still combative, within 1.5 hours . Her arterial pH had then increased to 7.25 and her PC02 was 44mm Hg. Three hours after the seizures her blood theophylline level was 23 ).tg/ml. Her condition stabilised readily and subsequently her daily dose of 'Theo-Dur' was decreased. There was no history of seizures in the girl or her family.

Case 4: An asthmatiC boy, aged 11 years, who had a history of seizures was receiving long term treatment with phenytoin and 'Theo-Our' 650 mg/day. Phenytoin was stopped after a 3 year seizure-free period. Two weeks later he had a fever and sore throat for which he was prescribed erythromycin 250mg qid. The boy had a generalised tonic-clonic seizure after 7 days' erythromycin therapy. In hospital he was given diazepam and phenytoin. His serum theophylline level was 31 .7 /.Lg/ml. After 1-2 hours the seizure was brought under control. His arterial pH was 6.B, PaC02 was 127mm Hg, Pa02 was 153mm Hg and arterial bicarbonate level was 19 mEq/l. The boy was combative, then his colour became dusky and his respiration became Shallow. Soon aller his heart rate rose to 180 beats/min and generalised seizures and coma occurred. The seizures lasted for 3 hours despite treatment with diazepam, phenytoin and paraldehyde. He had a h igh temperature (106.2°Fl, became tranSiently hypotensive and anuric. The child 's condition was stabilised but later he was found to be having focal seizures and was unresponsive to neurological tests.

Richards. W ." Church . J A. and Bren t. O.K.: Annals or Allergy 54 216·219 (Ap r 1985)