Clinical studies have shown that S (-) Amlodipine when combined with aspirin, nitrates, beta-blockers, statins, ACE inhibitors, H2 blockers, and Proton Pump Inhibitors produced no drug interactions. No drug interaction has been reported with the use of Atenolol.
Warnings :
Increased Angina and/or Myocardial Infarction
Rarely, patients, particularly those with severe obstructive coronary artery disease, have developed documented increased frequency, duration and/or severity of angina or acute myocardial infarction on starting calcium channel blocker therapy or at the time of dosage increase. The mechanism of this effect has not been elucidated.
Cardiac Failure
Sympathetic stimulation is necessary in supporting circulatory function in congestive heart failure, and beta blockade carries the potential hazard of further depressing myocardial contractility and precipitating more severe failure. In patients who have congestive heart failure controlled by digitalis and/or diuretics, Atenolol should be administered cautiously. Both digitalis and Atenolol slow AV conduction. In general, calcium channel blockers should also be used with caution in patients with heart failure.
Bronchospastic Diseases
Patients with bronchospastic disease should, in general, not receive beta blockers. Because of its relative β1 selectivity, however, Atenolol may be used with caution in patients with bronchospastic disease who do not respond to, or cannot tolerate, other antihypertensive treatment.
Thyrotoxicosis
Beta-adrenergic blockade may mask certain clinical signs (eg, tachycardia) of hyperthyroidism. Abrupt withdrawal of beta blockade might precipitate a thyroid storm; therefore, patients suspected of developing thyrotoxicosis from which Atenolol therapy is to be withdrawn and should be monitored closely.
Untreated Pheochromocytoma
Atenolol should not be given to patients with untreated pheochromocytoma.