Theophylline toxicity
See theophylline for general drug information.
Background
- Primarily used as a bronchodilator, however rarely used now due to better available options
- Also studied for treatment of Acute Mountain Sickness and Contrast-Induced Nephropathy
- PO available as elixer and capsule (12 or 24-hour extended release)
- IV as aminophylline (shorter acting than PO)
- Mechanism of action[1]:
- Release of endogenous catecholamines → β2 agonism → bronchodilation
- PDE inhibition → increases cAMP
- Adenosine antagonist
Clinical Features
- Cardiovascular
- Sinus Tachycardia
- Atrial/Ventricular arrhythmias
- Hypotension (due to β2-mediated vasodilation)
- Metabolic
- Neurologic
- Tremor
- Agitation
- Seizure
- GI
Differential Diagnosis
Evaluation
- Theophylline level[2]
- 10–20 μg/mL - Therapeutic
- 20-80 μg/mL - Toxic level
- 80-100 μg/mL - Severe toxicity or death
- ECG
- Metabolic panel
- Lactic acid level
- CK
- Evaluate for co-ingestion
Management
- Supportive care is the mainstay of treatment
- Cardiovascular
- Norepinephrine (alpha-agonist) for hypotension resistant to IVF
- Refractory hypotension may respond to non-selective beta-blockers[1]
- Beta-blockers (esmolol preferred due to short half-life) for tachydysrhythmias
- GI decontamination (Multidose Activated Charcoal, Whole Bowel Irrigation)
- Consider in recent severe overdose
- Contraindications: unsecured airway, nausea/vomiting, ileus, Bowel Obstruction, or need for emergent endoscopy
- Seizures
- Dialysis or plasmapheresis
- Indicated in seizures, severe arrhythmias, hypotension, serum level >90 μg/mL (>40 μg/mL in chronic ingestion)
Disposition
- Almost all patients will require admission
- Can consider discharge with close followup (in conjunction with toxicology) if unintentional overdose, asymptomatic, and normal vital signs
See Also
External Links
References
- ↑ 1.0 1.1 Fisher, J., & Graudins, A. (2015). Intermittent haemodialysis and sustained low-efficiency dialysis (SLED) for acute theophylline toxicity. Journal of medical toxicology : official journal of the American College of Medical Toxicology, 11(3), 359-63.
- ↑ Aggelopoulou, E., Tzortzis, S., Tsiourantani, F., Agrios, I., & Lazaridis, K. (2018). Atrial Fibrillation and Shock: Unmasking Theophylline Toxicity. Medical principles and practice : international journal of the Kuwait University, Health Science Centre, 27(4), 387-391.