Enhanced elimination

Multiple-dose activated charcoal

Multiple-dose activated charcoal has been shown to increase the elimination of theophylline or caffeine. For theophylline ingestions of more than 30 mg/kg, or caffeine ingestions of more than 50 mg/kg, consider multiple-dose activated charcoal—seek advice from a clinical toxicologist. Patients must be alert, cooperative and able to protect their airway to drink a dose of activated charcoal, or be intubated and receive activated charcoal via a nasogastric or orogastric tube—confirm correct placement of the nasogastric or orogastric tube beforehand.

Haemodialysis

Haemodialysis increases clearance of theophylline by about 1.5- to 2-fold. Although not as effective as haemoperfusion (2- to 5-fold increased clearance), haemodialysis is more readily available and associated with fewer adverse effects (eg coagulopathy, electrolyte disturbances). There is no evidence that haemodialysis is more effective than multiple-dose activated charcoal.

Discuss the benefits and harms of haemodialysis versus multiple-dose activated charcoal with a clinical toxicologist. Suggested indications for haemodialysis are:

• serum theophylline concentration of more than 550 micromol/L (100 mg/L) in acute poisoning
• serum theophylline concentration of more than 330 micromol/L (60 mg/L) in chronic poisoning
• severe toxicity following theophylline or caffeine poisoning.

For more information on haemodialysis, see here.