GuidelinesOther guideline
Theophylline Poisoning
Theophylline poisoning
Mechanism of toxicity
Toxic dose
Symptoms and signs of poisoning
Special investigations
Management
Mechanism of toxicity
Stimulates catecholamine release.
Toxic dose
Symptoms and signs of poisoning
- Gastrointestinal: nausea and vomiting (which may be severe and intractable), abdominal pain, diarrhoea, gastrointestinal haemorrhage
- Central nervous system: agitation, restlessness, dilated pupils, hyper-reflexia, convulsions (tend to occur in those with plasma concentrations > 50 mcg/mL), coma
- Cardiovascular: tachycardia, arrhythmias
- Electrolytes: profound hypokalaemia, hyperglycaemia and metabolic acidosis
Special investigations
- Theophylline blood concentrations
- The therapeutic range is 55–110 micromol/L (10–20 mcg/mL)
- Convulsion tend to occur at >275 micromol/L (> 50 mcg/mL)
- Concentrations may continue to rise for 8 hours or more after ingestion when sustained-release preparations have been ingested.
- Electrolytes: hypokalaemia
- Cardiac monitoring: cardiac dysrhythmias as well as cardiac arrest
Management
| Intervention | Not effective | Consider | Indicated |
| Gastric lavage | -- | ||
| Early post-ingestion activated charcoal | -- | -- | |
| Multiple dose activated charcoal | -- | -- | |
| Dialysis | -- | -- | |
| Charcoal haemoperfusion | -- | -- |
- Activated charcoal: multiple dose activated charcoal (MDAC) should be considered in a patient who has ingested a life-threatening amount of theophylline (especially with slow-release preparations). Control intractable vomiting with ondansetron 8 mg IVI.
- Severe poisoning: charcoal haemoperfusion or haemodialysis should be considered in severe poisoning, refractory seizures, cardiovascular compromise, and in patients with delayed theophylline clearance (including the older patient and those with significant liver disease or cardiac failure). MDAC may be as effective as haemoperfusion.
Symptomatic and supportive:
- Electrolytes: correct hydration and hypokalaemia.
- Convulsions: convulsions can be controlled by slow IV administration of diazepam.
- Arrythmias: beta-blocking agents (except in asthmatics), lidocaine or calcium-channel blockers (e.g. verapamil) may be useful in treating arrhythmias.
Monitoring:
- Electrolytes and arrhythmias