- Prescribed treatment for PO Stable angina, Prinzmetal’s angina and Hypertension.
Adult : PO Stable angina; HTN; Prinzmetal’s angina Initial: 5 mg once daily. Max: 10 mg once daily.
Severe hypotension, shock (including cardiogenic shock), obstruction of the outflow tract of the left ventricle (e.g. aortic stenosis), haemodynamically unstable heart failure after acute MI.
Patients w/ cardiac failure. Hepatic and renal impairment. Elderly. Pregnancy and lactation.
Adverse drug reactions:
Somnolence, dizziness, headache, ankle swelling, oedema, flushing, fatigue, palpitations, abdominal pain, nausea. Rarely, confusion, rash, gingival hyperplasia, muscle cramps, dyspnoea
Plasma concentrations may be elevated w/ CYP3A4 inhibitors (e.g. azole antifungals, ritonavir). Concomitant therapy w/ simvastatin may increase risk of myopathy including rhabdomyolysis. May increase ciclosporin plasma levels and conivaptan.
Symptoms: Excessive peripheral vasodilation w/ marked hypotension and possibly a reflex tachycardia. Management: Symptomatic and supportive treatment. A vasoconstrictor may be beneficial in restoring vascular tone and BP. Ca gluconate IV may be used to reverse the effects of Ca channel blockade. Gastric lavage may be useful in some cases.
Mechanism of action:
Amlodipine relaxes peripheral and coronary vascular smooth muscle. It produces coronary vasodilation by inhibiting the entry of Ca ions into the slow channels or select voltage-sensitive channels of the vascular smooth muscle and myocardium during depolarisation. It also increases myocardial oxygen delivery in patients w/ vasospastic angina.