carvedilol × Insulin

Beta-blockers mask adrenergic hypoglycaemia symptoms (tachycardia, tremor, sweating). In diabetics on insulin, the risk of severe unrecognised hypoglycaemia rises.

Confusion, vision changes, loss of contact, seizures. Tachycardia, tremor, and sweating are suppressed — the patient misses the hypoglycaemia.

Prescribe carvedilol cautiously in diabetes. In heart failure with reduced ejection fraction, carvedilol remains first-line (improves survival) — teach the patient to recognise hypoglycaemia by any unusual sensation. On insulin, intensify glucose self-monitoring (4 times daily) for the first month. For hypertension without heart failure, alternatives: ACE inhibitor or ARB with a diuretic.