설명
Beta-blockers such as metoprolol mask the adrenergic warning symptoms of hypoglycaemia (tachycardia, tremor) and may prolong hypoglycaemic episodes in insulin-treated patients.
기전
Metoprolol blocks beta-1 (and partially beta-2) adrenoceptors, suppressing catecholamine-mediated tachycardia and tremor that normally warn patients of hypoglycaemia; sweating (cholinergic) remains intact. Beta-2 blockade also reduces hepatic glycogenolysis, slowing glucose recovery.
임상적 중요성
Clinically documented in diabetic patients on insulin; hypoglycaemic episodes may be prolonged and go unrecognised. Cardioselective agents (metoprolol) carry lower risk than non-selective beta-blockers.
관리 방법
Counsel patients to rely on diaphoresis as a hypoglycaemia warning sign; increase blood glucose monitoring frequency; consider cardioselective agents when beta-blockade is required; adjust insulin doses cautiously.