Moderate
Bisoprolol × Glibenclamide
Selective beta-adrenergic blockers×Oral hypoglycemic agents. Sulfonylureas
Mechanism
Beta-blockers mask adrenergic hypoglycaemia symptoms (tachycardia, tremor, sweating), leaving only neuroglycopenic symptoms (confusion, weakness). Glibenclamide often causes hypoglycaemia, especially in older patients.
Symptoms
Sudden confusion, weakness, ataxia without preceding tachycardia or sweating. Older patients: risk of severe hypoglycaemia without warning symptoms.
Management
Warn the patient that beta-blockers mask hypoglycaemia warning signs. Check glucose more often (4 times daily in the first week, then by self-monitoring). In older patients, prefer gliclazide (less hypoglycaemia) or metformin/DPP-4 inhibitor over glibenclamide.