Theophylline Poisoning

Description

Diagnostic criteria

General and supportive measures

Medicine treatment

Referral

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ICD-10 code: T48.6

DESCRIPTION

Agents such as aminophylline and caffeine have similar features in overdose. Sustained release preparations can cause prolonged toxicity. Toxicity can occur with therapeutic dosing.

DIAGNOSTIC CRITERIA

Clinical

• Mainly affects the gastrointestinal, cardiovascular and central nervous systems.
  • Central nervous system: agitation, tremor, seizures, coma, hyper-ventilation.
  • Gastrointestinal tract: nausea and vomiting.
  • Cardiovascular: tachycardia, arrhythmias, hypotension.

Investigations

• Serum levels; a theophylline level 111 µmol/L (>20 mg/L ) is considered toxic.
• Hyperglycaemia.
• Hypokalaemia.
• Respiratory alkalosis and/or metabolic acidosis.

GENERAL AND SUPPORTIVE MEASURES

• Observe all patients who have ingested 10 mg/kg or more of theophylline for at least 4 hours for a normal release preparation and at least 12 hours for a sustained release preparation.
• Manage hypotension.
• Cardiac monitoring.
• Potassium levels should be monitored and replaced if required.

MEDICINE TREATMENT

• Ondansetron for vomiting. See: Palliative care.
• Activated charcoal. Repeated doses may be required to enhance elimination of theophylline. See: Poisoning, Treatment.

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Note:
Phenytoin should be avoided (due to potential cardiotoxicity).

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LoE III⁴

REFERRAL

Refer for consideration of haemodialysis, severe poisonings as evidenced by:

• serum theophylline > 555 µmol/L (> 100 mg/L),
• seizures,
• refractory shock,
• life-threatening dysrhythmias,
• rising theophylline level and/or clinical deterioration despite optimal care.

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Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Paediatrics, 2023 Edition

Chapter 18: Poisoning,  18.1 Poisoning,  18.1.18 Theophylline Poisoning