Theophylline overdose Treated with haemoperfusion and p­blocker.

Intentional overdosing with theophylline is becoming more frequent as the medication is more widely used. Guidelines are needed to deal with the symptoms of overdose which include cardiac arrhythmias, hypotension, tremor, agitation, hyperglycaemia, hypokalaemia and hypophosphalaemia.

The 5 cases of theophylline overdose reported had peak serum theophylline levels ranging from 96-194 I'g/ml and, despite these high concentrations, no seizures or deaths occurred. Initial treatment with oral activated charcoal and magnesium citrate was repeated hourly until charcoal was visible in the stools. The effect of high plasma levels of adrenaline [epinephrine) and noradrenaline [norepinephrine] found in these patients on /3-adrenergically mediated functions, was thought to be potentiated by theophylline-induced intraceullar phosphodiesterase inhibition . Hypotension which resulted from this uncontrolled p-adrenergic stimulation produced by theophylline toxicity was successfully treated with 2mg IV propranolol. (One patient was first given dopamine with no response). Two patients received IV diazepam Smg to control agitation. IV potassium, phosphate and sodium bicarbonate were given to correct metabolic abnormalities. All patients were also haemoperlused with resin cartridges which , although accompanied by haemorrhagic complications in 3 of the 5 cases (decreased platelets leading to haematoma formation in 2 patients and haematuria and blood-stained aspirate in another), resulted in rapid clinical improvement and reduction of serum theophylline in al\ patients.

Theophyll ine overdose should be managed with careful monitoring, intensive support and thorough evacuation of the drug from the GI tract. Metabolic abnormalities shOUld be expected and treated. IV propranolol may be especially useful in refractory hypotension. Haemoperfusion should be considered for patients with serum levels over 60 I'g/ml or for those with potentially fatal complications. Biberstem. M.P.: Ziegler. M.G. and Ward. D.M .. Western Journal of Medicine 141 ' 485·490 (Oct 1984)