Detailed Drug Information:

DRUG CLASS AND MECHANISM: Atenolol is a beta-adrenergic blockingagent. Atenolol blocks the action of the sympathetic nervoussystem, a portion of the involuntary nervous system. The sympathetic nervous system stimulates the pace of the heart beat. By blocking the action of these nerves, atenolol reduces the heart rate and is useful in treatingabnormally rapid heart rhythms. Atenolol also reduces the force of heartmuscle contraction and lowers blood pressure. By reducing the heart rateand the force of muscle contraction, atenolol reduces heart muscle oxygendemand. Since angina occurs when oxygen demand of the heart exceedssupply, atenolol is helpful in treating angina.

PREPARATIONS: Tablets: 25 mg, 50 mg, 100 mg.

STORAGE: Tablets should be stored at room temperature in atightly closed container.

PRESCRIBED FOR: Atenolol is prescribed for patients with highblood pressure (hypertension). It is also used to treat chest pain (anginapectoris) related to coronary artery disease. Atenolol is also useful inslowing and regulating certain types of abnormally rapid heart rates(tachycardias). Other uses for atenolol include the prevention of migraineheadaches and the treatment of certain types of tremors (familial orhereditary essential tremors).

DOSING: Should be taken before meals or at bedtime.

DRUG INTERACTIONS: Atenolol can aggravate breathing difficultiesin patients with asthma, chronic bronchitis, or emphysema. In patientswith existing slow heart rates (bradycardias) and heart blocks (defects inthe electrical conduction of the heart), atenolol can cause dangerouslyslow heart rates, and even shock. Atenolol reduces the force of heartmuscle contraction and can aggravate symptoms of heart failure. Calciumchannel blockers, and digoxin (Lanoxin) can cause lowering of blood pressure and heart rate to dangerous levels when administered togetherwith atenolol. In patients with coronary artery disease, abruptly stoppingatenolol can suddenly worsen angina, and occasionally precipitate heartattacks. If it is necessary to discontinue atenolol, its dosage can bereduced gradually over several weeks. Atenolol can mask the early warningsymptoms of low blood sugar (hypoglycemia), and should be used withcaution in patients receiving treatment for diabetes. It is not habitforming.

PREGNANCY: Atenolol may cause harm and growth retardation in thefetus when given to pregnant women.

SIDE EFFECTS: Atenolol is generally well tolerated, and side effects are mild and transient. Rare side effects include abdominal cramps, diarrhea, constipation, fatigue, insomnia, nausea, depression, dreaming, memory loss, fever, impotence, lightheadedness, slow heart rate,low blood pressure, numbness, tingling, cold extremities, sore throat, andshortness of breath or wheezing.