Duovas 5 mg/40 mg Tablet is a combination antihypertensive medication produced by Radiant Pharmaceuticals Ltd. It contains two active ingredients: Amlodipine (5 mg), a calcium channel blocker, and Olmesartan Medoxomil (40 mg), an angiotensin II receptor blocker (ARB). Amlodipine works by inhibiting the influx of calcium ions into vascular smooth muscle and cardiac muscle, leading to vasodilation and reduced peripheral vascular resistance, thereby lowering blood pressure. Olmesartan Medoxomil selectively blocks the binding of angiotensin II to the AT1 receptor, preventing vasoconstriction and aldosterone secretion, which also contributes to blood pressure reduction. This combination is indicated for the treatment of hypertension, either alone or in combination with other antihypertensive agents. It may also be used as initial therapy in patients who are likely to need multiple antihypertensive agents to achieve their blood pressure goals. The usual starting dose is one tablet (5 mg/40 mg) once daily, which may be increased to a maximum of two tablets (10 mg/40 mg) once daily after 1 to 2 weeks, depending on the patient's response. Duovas 5 mg/40 mg Tablet is contraindicated during pregnancy, especially in the second and third trimesters, as it can cause fetal harm. It should also be avoided in breastfeeding women and used with caution in patients with renal or hepatic impairment. Common side effects include peripheral edema, dizziness, flushing, and palpitations. Patients should be monitored for renal function and electrolytes during treatment. Grapefruit and grapefruit juice should be avoided, as they can increase the levels of Amlodipine in the blood, leading to an unpredictable decrease in blood pressure.