Tenormin is the brand name for the medication atenolol, a selective beta-blocker prescribed primarily for high blood pressure and certain cardiac disorders. The drug is classified as an oral tablet that works by blocking beta-adrenergic receptors on the heart and blood vessels. By inhibiting these receptors the medication reduces the effects of adrenaline and noradrenaline causing a slower heart rate and lower blood pressure. This blockade leads to decreased myocardial oxygen demand and improved blood flow to the heart muscle. The primary active ingredient atenolol produces its therapeutic effect by selectively binding to beta-1 receptors with minimal impact on beta-2 receptors. The resulting reduction in cardiac output and renin release helps maintain a stable cardiovascular state and manages symptoms of angina and arrhythmias.

Tenormin is the brand name for the drug atenolol, a selective beta-1 adrenergic receptor blocker used to treat high blood pressure and angina. It works by binding to beta-1 receptors in the heart, reducing the effects of adrenaline and lowering heart rate. By decreasing heart rate and the force of contraction, it reduces the workload on the heart and lowers blood pressure. The blockade of beta-1 receptors also decreases cardiac output, which further contributes to its antihypertensive effect. Atenolol does not significantly affect beta-2 receptors, so it has minimal influence on bronchial and vascular smooth muscle. This selectivity allows it to provide therapeutic benefits with fewer bronchospastic side effects compared to non-selective beta blockers. The combined actions of heart rate reduction, lowered cardiac output, and selective receptor blockade produce its intended clinical effects.

Tenormin may cause dizziness or lightheadedness especially after the first few doses. Some people experience fatigue or unusual tiredness that can affect daily activities. Slow heart rate is a common cardiovascular effect that usually does not require treatment. Cold hands or feet can occur due to reduced blood flow in the extremities. Erection problems or decreased libido have been reported in a small number of users. Depression or mood changes may appear, though they are less frequent. Shortness of breath or wheezing can develop in individuals with asthma, requiring careful monitoring. Swelling of the ankles or feet may indicate fluid retention and should be observed.

Tenormin may cause dizziness or lightheadedness especially when standing up quickly. It can lead to fatigue or unusual tiredness in some users. Some people experience cold hands or feet due to reduced circulation. It is possible to develop mild breathing difficulties if the medication slows the heart rate too much. Occasionally swelling of the ankles or feet has been reported. Headache or trouble sleeping are other noted reactions.