A Case Report of Severe Theophylline Poisoning: Management and Review of Literature.
It blocks adenosine receptors and acts as a phosphodiesterase inhibitor, increasing beta-adrenergic effects and increases the release of catecholamines. Theophylline is a plant derived methyl xanthine
compound that is similar to caffeine. It has up to 90% oral bioavailability and has a small volume of distribution of approximately 0.5L/kg. The half-life is approximately 8 to 11-hours with clearance lowered in overdose as elimination at high concentrations becomes zero-order.
Acute theophylline toxicity manifestations can occur with doses from 7.5 mg/kg. It presents with a constellation of clinical features that progress with severity as theophylline plasma concentration increases. At lower toxic plasma levels, gastrointestinal features such as nausea and vomiting and neurological features such as headache, agitation and muscle tremor can occur. With higher toxic plasma levels, more severe signs and symptoms such as hypotension, arrhythmia and seizures can occur. Metabolic derangements are more severe in acute toxicity and the ones commonly seen include hypokalaemia and hyperglycaemia. In chronic theophylline intoxication, cardiovascular and neurological manifestation are more prominent. Risk of major toxicity resulting in morbidity correlates with serum theophylline levels in acute toxicity and extreme of ages in chronic toxicity.
Theophylline poisoning leads to multisystem dysfunction with high risk of serious cardiovascular instability and neurological complications. The immediate management of theophylline overdose is often that of its life-threatening complications.
Another serious complication of theophylline poisoning is theophylline-associated seizures (TAS), which can be intractable to first line seizure therapy with benzodiazepine, leading to status epilepticus.25 Theophylline’s antagonistic effect on adenosine receptor A2 and its inhibition of gamma-aminobutyric acid receptors are some of the proposed mechanism of theophylline’s interaction with benzodiazepine, rendering it less useful in aborting TAS.
Toxicol Forensic Med Open J. 2021; 6(1): 20-25. doi: 10.17140/TFMOJ-6-138