Theophylline overdose With concomitant IV aminophylline: 8 patients

The treatment charts of 8 patients with chronic obstructive airways disorder or asthma and/or cardiac failure and serum theophylline levels of 159 to > 220 ILmol/L were reviewed. The patients were 70-85 years of age and each patient was receiving oral theophylline (125-250mg tid in 4 patients, 250mg bid in 1, 100mg bid + 300mg at night in 1 and single 300 and 200mg doses, respectively, in 2) and concomitant IV aminophylline 125-1200 mg/day. Further, total theophylline dosages were 12.5-32 mg/kg/day and each theophylline serum level was above the upper limit of the therapeutic range (110 Ilmol/L).

Two patients with serum theophylline levels of 172 or 173 IlmoljL showed no signs of toxicity while 4 who experienced rapid atrial fibrillation, diarrhoea, nausea and arrhythmia or atrial fibrillation and fits recovered. Two with advanced obstructive airways disease and pulmonary failure had theophylline levels of > 220 Ilmol/L and 189 Ilmol/L, respectively, and died.

The authors concluded that toxic theophylline levels would develop quickly in these elderly patients with hypoxia and heart failure and, 'clearly, the coadministration of theophylline by mouth with aminophylline by the intravenous route is a practice to be discouraged' . Frewin DB. Cooper OJ Medical Journal of Australia 144. 481·482, 28 Apr 1986

8 Reactions® 24 May 1986 0157-7271/86/1026-0008/0$01.00/0 © ADIS Press