indication

For the management of hypertention and long-term management of patients with angina pectoris

pharmacology

Atenolol, a competitive beta(1)-selective adrenergic antagonist, has the lowest lipid solubility of this drug class. Although it is similar to metoprolol, atenolol differs from pindolol and propranolol in that it does not have intrinsic sympathomimetic properties or membrane-stabilizing activity. Atenolol is used alone or with chlorthalidone in the management of hypertension and edema.

mechanism of action

Like metoprolol, atenolol competes with sympathomimetic neurotransmitters such as catecholamines for binding at beta(1)-adrenergic receptors in the heart and vascular smooth muscle, inhibiting sympathetic stimulation. This results in a reduction in resting heart rate, cardiac output, systolic and diastolic blood pressure, and reflex orthostatic hypotension. Higher doses of atenolol also competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles.

toxicity

LD₅₀=2000-3000 mg/kg(orally in mice). Symptoms of an atenolol overdose include a slow heart beat, shortness of breath, fainting, dizziness, weakness, confusion, nausea, and vomiting.

biotransformation

Hepatic (minimal)

absorption

Approximately 50% of an oral dose is absorbed from the gastrointestinal tract, the remainder being excreted unchanged in the feces.

half life

6-7 hours

route of elimination

Approximately 50% of an oral dose is absorbed from the gastrointestinal tract, the remainder being excreted unchanged in the feces. Unlike propranolol or metoprolol, but like nadolol, atenolol undergoes little or no metabolism by the liver, and the absorbed portion is eliminated primarily by renal excretion.

drug interactions

Acetohexamide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Ampicillin: Ampicillin decreases bioavailability of atenolol

Chlorpropamide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Clonidine: Increased hypertension when clonidine stopped

Dihydroergotamine: Ischemia with risk of gangrene

Dihydroergotoxine: Ischemia with risk of gangrene

Diltiazem: Increased risk of bradycardia

Disopyramide: The beta-blocker, atenolol, may increase the toxicity of disopyramide.

Epinephrine: Hypertension, then bradycardia

Ergonovine: Ischmeia with risk of gangrene

Ergotamine: Ischemia with risk of gangrene

Fenoterol: Antagonism

Formoterol: Antagonism

Gliclazide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Glipizide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Glisoxepide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Glyburide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Glycodiazine: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Ibuprofen: Risk of inhibition of renal prostaglandins

Indomethacin: Risk of inhibition of renal prostaglandins

Insulin Aspart: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Insulin Detemir: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Insulin Glargine: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Insulin Glulisine: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Insulin Lispro: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Isoproterenol: Antagonism

Lidocaine: The beta-blocker, atenolol, may increase the effect and toxicity of lidocaine.

Methysergide: Ischemia with risk of gangrene

Orciprenaline: Antagonism

Pipobroman: Antagonism

Pirbuterol: Antagonism

Piroxicam: Risk of inhibition of renal prostaglandins

Prazosin: Risk of hypotension at the beginning of therapy

Procaterol: Antagonism

Repaglinide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Salbutamol: Antagonism

Salmeterol: Antagonism

Terazosin: Increased risk of hypotension. Initiate concomitant therapy cautiously.

Terbutaline: Antagonism

Tolazamide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Tolbutamide: The beta-blocker, atenolol, may decrease symptoms of hypoglycemia.

Treprostinil: Additive hypotensive effect. Monitor antihypertensive therapy during concomitant use.

Verapamil: Increased effect of both drugs