Atenolol is a beta-adrenaceptor antagonist, or a more commonly known as a beta blocker. Beta blockers are competative inhibitors and interfere with the action of stimulating hormones on beta-adrenergic receptors in the nervous system. Beta blockers can be subdivided into two distinct groups, known as beta1 and beta2. Beta 1 blockers mainly affect the heart, beta2 blockers mainly affect receptors in bronchial tissue.
Most beta blockers are non specific, ie they have both beta1 and beta2 effects. The table below shows which of the beta blockers are specific i.e. cardioselcective and which are non specific.
| Beta Blocker | Beta1Selectivity |
|---|---|
| Acebutolol | |
| Atenolol | |
| Betaxolol | |
| Esmolol | |
| Labetolol | |
| Metoprolol | |
| Nadolol | |
| Oxprenolol | |
| Pindolol | |
| Propanolol | |
| Sotalol | |
| Timolol |
Atenolol works by competing for receptor sites on, in atenolol's case, cardiac muscle. This slows down the strength of the heart`s contractions and reduces its oxygen requirements and the volume of blood it has to pump. Hypertension (high blood pressure) may be treated with these drugs because of their ability to increase the diameter of the blood vessels thus allowing blood to flow under less pressure. Some of these medicines include a diuretic to help reduce blood pressure by increasing the body`s excretion of excess fluid. Beta blockers are also used to treat Myocardial infarction (heart attack) and Arrhythmias (rhythm disorders), angina (chest pains), and disorders arising from decreased circulation and vascular constriction, including migraine.
