11.6 : 狭心症治療薬: 硝酸塩とベータ遮断薬

Anti-anginal drugs, such as organic nitrates and β-blockers, are used to treat angina pectoris, characterized by chest pain due to reduced blood flow to the heart.

Organic nitrates, such as nitroglycerins are metabolized to release nitric oxide, which activates guanylyl cyclase and increases cGMP production. This relaxes vascular smooth muscles, leading to vasodilation and improving coronary blood flow.

Nitroglycerin is administered sublingually for a rapid onset of action.

Common side effects include headaches, postural hypotension, facial flushing, and tachycardia.

β-blockers such as atenolol and metoprolol selectively block adrenaline and noradrenaline binding at β₁-adrenergic receptors in the vascular smooth muscle and cardiac muscle cells.

These drugs reduce myocardial oxygen demand by lowering the heart rate, myocardial contraction force, and systemic blood pressure.

β-blockers are typically given orally, with effects seen within an hour.

Common side effects of β-blockers include fatigue, cold extremities, hypotension, and bradycardia.