Penbutolol drug interactions

Penbutolol
LEVATOL ® FDA Package Insert
Indications and Usage
Dosage and Administration
Contraindications
Warnings and Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Overdosage
Description
Clinical Pharmacology
Nonclinical Toxicology
How Supplied/Storage and Handling
Patient Counseling Information
Labels and Packages
Clinical Trials on Penbutolol
ClinicalTrials.gov

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sheng Shi, M.D. [2]

Drug Interactions

levatol® has been used in combination with hydrochlorothiazide in at least 100 patients without unexpected adverse reactions.

In one study, the combination of penbutolol and alcohol increased the number of errors in the eye-hand psychomotor function test.

Penbutolol increases the volume of distribution of lidocaine in normal subjects. This could result in a requirement for higher loading doses of lidocaine.

Cimetidine has no effect on the clearance of penbutolol. The major metabolite of penbutolol is a glucuronide, and it has been shown that cimetidine does not inhibit glucuronidation.

Synergistic hypotensive effects, bradycardia, and arrhythmias have been reported in some patients receiving ß-adrenergic blocking agents when an oral calcium antagonist was added to the treatment regimen.

Generally, levatol® should not be used in patients receiving catecholamine-depleting drugs.

Digoxin

Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia.

Anesthesia

Care should be taken when using anesthetic agents that depress the myocardium, such as ether, cyclopropane, and trichloroethylene, and it is prudent to use the lowest possible dose of levatol®. levatol®, like other ß-blockers, is a competitive inhibitor of ß-receptor agonists, and its effect on the heart can be reversed by cautious administration of such agents (eg, dobutamine or isoproterenol — see OVERDOSAGE). Manifestations of excessive vagal tone (eg, profound bradycardia, hypotension) may be corrected with atropine 1 to 3 mg IV in divided doses.