Theophylline overdose

Treatment with charcoal haemoperfusion The optimal management of patients with theophylline overdose is not well established. One therapeutic approach has mcluded the use of oral activated charcoal to delay gastrointestinal absorption of oral theophYlline. Recent studies have shown that mUltiple doses of activated charcoal increase the clearance of theophylline administered IV to normal volunteers. In order to evaluate the efficacy of charcoal haemoperfusion in the management of theophylline overdosage, the experience with 6 patients who were subjected to the procedure was reviewed. Adsorba 300e charcoal haemoperfusion cartridges were used in all patients and a blood flow rate of 4 ml/min/kg was maintained. Five of 6 patients had allegedly ingested 60-230 mg/kg of theophylline and had peak theophylline concentrations of 71-150 ILg/ml, 8 hours after ingestion. The remaining patient had an iatrogenically-induced peak theophylline concentration of 55 lLg/ml at the same time period and had been prescribed 1200 mg/day of sustained release theophylline. The duration of haemoperfusion varied from 2-3.5 hours. A rapid decrease in theophylline plasma concentrations occurred during hacmoperfusion with an apparent mean half-life of 1.3 hours. The calculated mean half-life before haemoperfusion was approximately 12 hours (this value may reflect continued absorption of theopbylline from sustained-release preparations). Clearances of theophylline calculated in 4 patients (ang~d from 2.3 to 4.9 rut/min/kg while the extraction ratios in the same subjects ranged from 0.82 to 1.00. Saturation of the charcoal cartridge was never a significant clinical problem that limited the usefu\ness of the procedure. Following the discontinuation of the haemoperfusion procedure there was a minimal rebound of the plasma theophylline concentrations (range 2.1 to 5.6 lLg/ml) in 4 patients. The haemoperfusion procedure although relatIVely safe. was associated with chins in 2 patients. tingling cxtremities in 1 patient and hypotension (which was easily managed) in 2 patients. From the above experience it is conduded that charcoal hacmoperfusion is a useful procedure for the treatment of theophylline intoxication. The procedure is relatively safe and prevents serious complications such as seizures. It is suggested that patients with theophylline concentrations greater than 60 lLg/ml at 4 hours after ingestion would benefit from haemoperfusion. Additionally, haemoperfusion should be considered in any patient with theophylline plasma concentrations of 30 lLg/ml or greater and 3 of the following 4 risk factors: age> 60 years; significant liver disease and/or

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congestive heart-failure: a theophylline half-life of 24 hours or greater; and a theophylline plasma concentration of 50 ILg/ml or greater. There is no evidence that haemoperfusion is of any benefit once complications of overdosage such as seizures have developed.

Park. G.D. cl al.: Amencan Journal of Medicine 74: 961 (Jun IQSJ)

Reactions 9 Sep 1983 7