Atenolol (50mg) + Losartan (50mg) is a fixed-dose combination (FDC) antihypertensive medication. It combines a cardioselective beta-1 adrenergic receptor blocker (Atenolol) with an angiotensin II receptor blocker (ARB) (Losartan). This combination provides a synergistic mechanism for blood pressure control by reducing heart rate, cardiac output, and blocking the vasoconstrictive and aldosterone-secreting effects of angiotensin II. It is indicated for the management of essential hypertension where monotherapy is insufficient. The combination may offer improved efficacy and tolerability compared to higher doses of individual components.
Adult: One tablet (Atenolol 50mg + Losartan 50mg) once daily. Dose may be adjusted based on blood pressure response, up to a maximum of Atenolol 100mg + Losartan 100mg per day, usually as two separate tablets of lower strength.
Note: Can be taken with or without food. Administer at the same time each day, preferably in the morning. Do not crush or chew. Swallow whole with a glass of water. Regular monitoring of blood pressure, heart rate, renal function, and serum potassium is essential.
This combination exerts a dual antihypertensive action. Atenolol competitively blocks beta-1 adrenergic receptors in the heart, reducing heart rate, myocardial contractility, and cardiac output. It also inhibits renin release from the kidneys. Losartan and its active metabolite selectively and competitively block the angiotensin II type 1 (AT1) receptor, preventing angiotensin II-mediated vasoconstriction, aldosterone secretion, sodium and water retention, and sympathetic nervous system stimulation. The combined effect leads to a more comprehensive reduction in peripheral vascular resistance and cardiac workload.
Pregnancy: CONTRANDICATED, especially in second and third trimester. Drugs that act directly on the renin-angiotensin system (like Losartan) can cause fetal injury and death, including oligohydramnios, fetal renal dysfunction, skull hypoplasia, and pulmonary hypoplasia. Atenolol is also associated with fetal growth restriction. Discontinue as soon as pregnancy is detected.
Driving: May cause dizziness, fatigue, or visual disturbances, especially at initiation or dose change. Patients should not drive or operate machinery until they know how the medication affects them.
| Other Antihypertensives (Diuretics, CCBs, ACEIs) | Additive hypotensive effect; risk of severe hypotension. | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | May reduce antihypertensive effect of Losartan; increase risk of renal impairment and hyperkalemia. | Major |
| Potassium supplements/Potassium-sparing diuretics (Spironolactone, Amiloride) | Increased risk of hyperkalemia with Losartan. | Major |
| Lithium | Losartan may increase lithium levels and toxicity. Monitor closely. | Major |
| Digoxin | Atenolol may increase digoxin concentration; risk of bradycardia. | Moderate |
| Clonidine | Withdrawal of clonidine while on beta-blocker can cause severe rebound hypertension. | Major |
| Insulin/Oral Hypoglycemics | Atenolol may mask tachycardia as a sign of hypoglycemia and may potentiate hypoglycemia. | Moderate |
| Verapamil/Diltiazem | Concomitant use with Atenolol increases risk of bradycardia, AV block, and heart failure. | Major |
| CYP2C9 Inhibitors (e.g., Fluconazole) | May increase Losartan levels. | Moderate |
| CYP2C9 Inducers (e.g., Rifampicin) | May decrease Losartan and active metabolite levels, reducing efficacy. | Moderate |
Same composition (Atenolol (50mg) + Losartan (50mg)), different brands: