"What are beta blockers?
The class of drugs called beta blockers were given their name because this class of medications counteracts the stimulatory effects of epinephrine (adrenaline) on the so-called beta-adrenergic receptors found"...
Most adverse effects have been mild and transient.
The frequency estimates in the following table were derived from controlled studies in hypertensive patients in which adverse reactions were either volunteered by the patient (US studies) or elicited, eg, by checklist (foreign studies). The reported frequency of elicited adverse effects was higher for both TENORMIN (atenolol tablets) and placebo-treated patients than when these reactions were volunteered. Where frequency of adverse effects of TENORMIN (atenolol tablets) and placebo is similar, causal relationship to TENORMIN (atenolol tablets) is uncertain.
|Total -Volunteered and Elicited
(Foreign+ US Studies)
|CENTRAL NERVOUS SYSTEM/NEURO MUSCULAR|
|RESPIRATORY see WARNINGS)|
Acute Myocardial Infarction
In a series of investigations in the treatment of acute myocardial infarction, bradycardia and hypotension occurred more commonly, as expected for any beta blocker, in atenolol-treated patients than in control patients. However, these usually responded to atropine and/or to withholding further dosage of atenolol. The incidence of heart failure was not increased by atenolol. Inotropic agents were infrequently used. The reported frequency of these and other events occurring during these investigations is given in the following table.
In a study of 477 patients, the following adverse events were reported during either intravenous and/or oral atenolol administration:
|Conventional Therapy Plus Atenolol||Conventional Therapy Alone|
|Heart Block BBB + Major||11||(4.5%)||10||(4.3%)|
|Axis Deviation Supraventricular||16||(6.6%)||28||(12%)|
|Atrial Flutter Ventricular||4||(1.6%)||7||(3%)|
|Total Cardiac Arrests Nonfatal Cardiac||4||(1.6%)||16||(6.9%)|
|Development of Ventricular Septal Defect||0||(0%)||2||(0.9%)|
|Development of Mitral Regurgitation||0||(0%)||2||(0.9%)|
In the subsequent International Study of Infarct Survival (ISIS-1) including over 16,000 patients of whom 8,037 were randomized to receive TENORMIN (atenolol tablets) treatment, the dosage of intravenous and subsequent oral TENORMIN (atenolol tablets) was either discontinued or reduced for the following reasons:
|Reasons for Reduced Dosage|
|IV Atenolol Reduced Dose (<5 mg)*||Oral Partial Dose|
|Heart Block (> first||5||(.06%)||143||(1.7%)|
|*Full dosage was 10 mg and some patients received less than 10 mg but more than 5 mg.|
During postmarketing experience with TENORMIN (atenolol tablets) , the following have been reported in temporal relationship to the use of the drug: elevated liver enzymes and/or bilirubin, hallucinations, headache, impotence, Peyronie's disease, postural hypotension which may be associated with syncope, psoriasiform rash or exacerbation of psoriasis, psychoses, purpura, reversible alopecia, thrombocytopenia, visual disturbance, sick sinus syndrome, and dry mouth. TENORMIN (atenolol tablets) , like other beta blockers, has been associated with the development of antinuclear antibodies (ANA), lupus syndrome, and Raynaud's phenomenon.
Potential Adverse Effects
In addition, a variety of adverse effects have been reported with other beta-adrenergic blocking agents, and may be considered potential adverse effects of TENORMIN (atenolol tablets) .
Central Nervous System: Reversible mental depression progressing to catatonia; an acute reversible syndrome characterized by disorientation of time and place; short-term memory loss; emotional lability with slightly clouded sensorium; and, decreased performance on neuropsychometrics.
Gastrointestinal: Mesenteric arterial thrombosis, ischemic colitis.
Other: Erythematous rash.
Miscellaneous: There have been reports of skin rashes and/or dry eyes associated with the use of beta-adrenergic blocking drugs. The reported incidence is small, and in most cases, the symptoms have cleared when treatment was withdrawn. Discontinuance of the drug should be considered if any such reaction is not otherwise explicable. Patients should be closely monitored following cessation of therapy. (See INDICATIONS.)
The oculomucocutaneous syndrome associated with the beta blocker practolol has not been reported with TENORMIN (atenolol tablets) . Furthermore, a number of patients who had previously demonstrated established practolol reactions were transferred to TENORMIN (atenolol tablets) therapy with subsequent resolution or quiescence of the reaction.
Read the Tenormin (atenolol tablets) Side Effects Center for a complete guide to possible side effects
Catecholamine-depleting drugs (eg, reserpine) may have an additive effect when given with beta-blocking agents. Patients treated with TENORMIN (atenolol tablets) plus a catecholamine depletor should therefore be closely observed for evidence of hypotension and/or marked bradycardia which may produce vertigo, syncope, or postural hypotension.
Calcium channel blockers may also have an additive effect when given with TENORMIN (See WARNINGS).
Disopyramide is a Type I antiarrhythmic drug with potent negative inotropic and chronotropic effects. Disopyramide has been associated with severe bradycardia, asystole and heart failure when administered with beta blockers.
Amiodarone is an antiarrhythmic agent with negative chronotropic properties that may be additive to those seen with beta blockers.
Beta blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. If the two drugs are coadministered, the beta blocker should be withdrawn several days before the gradual withdrawal of clonidine. If replacing clonidine by beta-blocker therapy, the introduction of beta blockers should be delayed for several days after clonidine administration has stopped.
Information on concurrent usage of atenolol and aspirin is limited. Data from several studies, ie, TIMI-II, ISIS-2, currently do not suggest any clinical interaction between aspirin and beta blockers in the acute myocardial infarction setting.
While taking beta blockers, patients with a history of anaphylactic reaction to a variety of allergens may have a more severe reaction on repeated challenge, either accidental, diagnostic or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat the allergic reaction.
Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia.
Read the Tenormin Drug Interactions Center for a complete guide to possible interactions
Last reviewed on RxList: 11/1/2010
This monograph has been modified to include the generic and brand name in many instances.
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