CompositionAmlodipine (5 mg) SALT INFORMATIONAmlodipine (5 mg) TYPICAL USAGE Mild to moderate hypertension. Angina pectoris. Prinzmetals angina. SIDE EFFECTS Headache, peripheral oedema, fatigue, somnolence, nausea, abdominal pain, flushing, dyspepsia, palpitations, dizziness. Rarely pruritus, rash, dyspnoea, asthenia, muscle cramps. Potentially Fatal: Hypotension, bradycardia, conductive system delay and CCF. DRUG INTERACTION Increased metabolism with rifampin. Reduced hypotensive effect with calcium. Potentiates effects of thiazide diuretics and ACE inhibitors. Avoid combination with ?-blockers in patients with markedly impaired left ventricular function. May increase serum levels of CYP1A2 substrates e.g. aminophylline, fluvoxamine, ropinirole. CYP3A4 inhibitors (e.g. clarithromycin, doxycycline, isoniazid, nicardipine) may increase the effects of amlodipine. Additive BP-lowering effects when used with sildenafil, tadalafil or vardenafil. MECHANISM OF ACTION Amlodipine relaxes peripheral and coronary vascular smooth muscle. It produces coronary vasodilation by inhibiting the entry of Ca ions into the voltage-sensitive channels of the vascular smooth muscle and myocardium during depolarisation. It also increases myocardial O2 delivery in patients with vasospastic angina.