Moderate
Amitriptyline × Glibenclamide
Tricyclic antidepressants (TCA)×Oral hypoglycemic agents. Sulfonylureas
Mechanism
TCAs may mask hypoglycaemia symptoms (tremor, tachycardia) via anticholinergic effect. No direct pharmacokinetic interaction.
Symptoms
Sudden confusion, weakness, ataxia without preceding tachycardia or sweating. Older patients: risk of severe hypoglycaemia without warning symptoms.
Management
Warn the patient that the TCA masks 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.
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.