Moderate
Propranolol × Theophylline
Non-selective beta blocker×Methylxanthine
Mechanism
Propranolol is non-selective, blocks bronchial β2 receptors, and antagonises theophylline's bronchodilator effect. It triggers bronchospasm in COPD or asthma.
Symptoms
Wheezing, dyspnoea, cough, asthma exacerbation. Symptoms appear within hours or days of starting propranolol.
Management
Do not prescribe propranolol in asthma or COPD. For atrial fibrillation, hypertension, or essential tremor in obstructive lung disease, alternatives: cardioselective beta-blockers (bisoprolol, metoprolol, nebivolol) at low doses under pulmonary function monitoring. For migraine prophylaxis, propranolol alternatives: topiramate or candesartan.