METOPROLO & AMLODIPINE
Metoprolol, a competitive, beta1-selective (cardioselective) adrenergic antagonist, is similar to atenolol in its moderate lipid solubility, lack of intrinsic sympathomimetic activity (ISA), and weak membrane stabilizing activity (MSA).
Metoprolol competes with adrenergic neurotransmitters such as catecholamines for binding at beta(1)-adrenergic receptors in the heart. Beta(1)-receptor blockade results in a decrease in heart rate, cardiac output, and blood pressure.
a. Absorption: Rapid and complete, 50%
b. Protein Binding: 12%
c.Metabolism: Primarily hepatic
d.Route of Elimination: Less than 5% of an oral dose of metoprolol is recovered unchanged in the urine; the rest is excreted by the kidneys as metabolites that appear to have no beta-blocking activity.
e.Half-Life: – 3-7 hours
For the management of acute myocardial infarction, angina pectoris, heart failure and mild to moderate hypertension. May be used to treat supraventricular and tachyarrhythmias and as prophylaxis for migraine headaches.
Amlodipine is used to treat high blood pressure (hypertension) or chest pain (angina) and other conditions caused by coronary artery disease. This medication is for use in adults and children who are at least 6 years old.
•Absorption: Amlodipine is well absorbed by the oral route with a mean oral bioavailability around 60%.
•Metabolism: It is metabolized in the liver to inactive metabolites via CYP3A4.
•Half-Life: The half-life of amlodipine is about 30-50 hours, and steady-state plasma concentrations are achieved after 7 to 8 days of daily dosing.
•Excretion: Renal elimination is the major route of excretion with about 60% of an administered dose recovered in urine, largely as inactive pyridine metabolites. However, renal impairment does not significantly influence amlodipine elimination.
•Treating high blood pressure in certain patients. It may be used alone or with other medicines.
•Amlodipine works by helping your blood vessels relax, which lowers blood pressure.