(atenolol)
Brand
Tenormin
Availability
- Tablets: 25 mg, 50 mg, 100 mg
- Injectable: 5 mg/mL in 10mL ampules
Pharmacology
A beta-1 adrenergic blocker, atenolol has no intrinsic sympathomimetic activity, or membrane stabilizing activity.
Effects from atenolol’s negative inotropic and chronotropic action are a decrease in the sinus heart rate, slowed AV conduction, a decrease in cardiac output, decreased myocardial oxygen demand and decreased blood pressure.
The drug is rapidly absorbed and distributed to most tissues. It crosses the placental barrier and is seen in cord blood. Fertility of male or female rats (evaluated at dose levels as high as 200 mg/kg/day or 100 times the maximum recommended human dose) however, were shown to be unaffected by the administration of atenolol.
Atenolol is biotransformed in the liver and excreted in both milk and urine.
Indications
Used in the treatment of hypertrophic cardiomyopathy, systemic hypertension, and tachyarrhythmias. Due atenolol’s specificity it may be used in CHF with caution.
Drug Interactions or Contraindications
- Aluminum containing acids, NSAIDs, salicylates, oral ampicillin, clonidine will decrease the effect of atenolol.
- Quinidine, diltiazem, verapamil will increase effects of atenolol.
- Increased toxicity is seen when used with lidocaine, insulins, and prazosin.
- Additive myocardial depression may occur when used concurrently with anesthetic agents.
- Furosemide and hydralazine when used with atenolol enhances the hypotensive effect.
Adverse Reactions
CNS: lethargy
CV: hypotension, bradycardia
GI: diarrhea
Dosage Recommendations
1 mg/lb, PO, BID 3, 12
or
0.2 mg/kg to 2 mg/kg, PO, q24hr 34, 40, 41, 42, 44
Considerations
- PATIENTS WITH BRONCHOSPASTIC DISEASE SHOULD, IN GENERAL, NOT RECEIVE BETA-BLOCKERS, but because of atenolol’s relative beta-1 selectivity, it may be used with caution, however the lowest dose possible to achieve desired effect should only be used.
- Use cautiously in cardiac failure.
- Don’t discontinue abruptly as it can exacerbate myocardial infarction. Drug should be withdrawn over 2 weeks.
- Store tablets at room temperature and away from light.
