Major
Carbamazepine × Theophylline
Antiepileptics. Carboxamide derivatives×Methylxanthine
Mechanism
Carbamazepine induces CYP1A2, which partly metabolises theophylline. Theophylline plasma levels fall by 25–50%; bronchodilator effect weakens.
Symptoms
Recurrence of asthma or COPD symptoms: dyspnoea, wheezing.
Management
During carbamazepine therapy, increase theophylline by 50% with level monitoring at 1–2 weeks. Alternative anticonvulsants without induction: levetiracetam, lamotrigine.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.