CompositionAmlodipine (5mg),Atenolol (50mg)
SALT INFORMATIONAmlodipine (5mg) 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. Atenolol (50mg) TYPICAL USAGE Hypertension, angina pectoris. Cardiac arrhythmias. Migraine prophylaxis. SIDE EFFECTS Bronchospasm; cold extremities, fatigue, dizziness, insomnia, lethargy, confusion, headache, depression, nightmares, nausea, diarrhoea, constipation, impotence and paraesthesia. Potentially Fatal: Heart failure, 2nd or 3rd degree AV block. DRUG INTERACTION Calcium channel blockers and digoxin can cause lowering of blood pressure and heart rate to dangerous levels when administered together with atenolol. Atenolol can mask the early warning symptoms of low blood sugar (hypoglycemia), and should be used with caution in patients receiving treatment for diabetes. MECHANISM OF ACTION Atenolol is a competitive cardioselective ?1-blocker. It does not have effect on ?2-receptors except in high doses. Its cardioselectivity is dose-related. Atenolol reduces resting and exercise-induced heart rate as well as myocardial contractility. Peripheral ?-blockade may result in vasoconstriction. Atenolol reduces BP and heart rate which results in reduced myocardial work and O2 requirement leading to improved exercise tolerance and reduced frequency and intensity of anginal attack.