At what theophylline levels does toxicity occur?

Therapeutic: 10–20 mg/L. Mild toxicity: 20–25 mg/L (nausea, tremor, tachycardia). Severe toxicity: >30 mg/L (ventricular arrhythmias, seizures). Chronic toxicity may cause seizures at lower levels (20–25 mg/L) in elderly patients. Acute overdose may be tolerated at higher levels before symptoms.

What factors increase theophylline levels dangerously?

CYP1A2 inhibitors: ciprofloxacin, erythromycin, fluvoxamine, cimetidine (double levels). Cardiac failure and liver cirrhosis (reduce clearance 50–60%). Smoking cessation (20–30% increase in half-life). Advanced age. Charcoal hemoperfusion is treatment for severe theophylline toxicity.

Theophylline Toxicity Threshold Assessment

Assess theophylline toxicity risk and predict seizure/cardiac arrhythmia threshold based on serum level, rate of level rise (acute vs chronic), patient age, and comorbidities.

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Theophylline Toxicity Threshold Assessment

Frequently Asked Questions

At what theophylline levels does toxicity occur?

What factors increase theophylline levels dangerously?