Page 19 - RxExam's Naplex Theory Review Part-1

www.pharmacyexam.com Krisman

TCAs and macrolide Co-administration of drugs prolonging the QT interval (such as
antibiotics certain phenothiazines, tricyclic antidepressants, certain macrolide
antibiotics, and Class I and III antiarrhythmics) is contraindicated
because of the potential risk of Torsade de Pointes-type ventricular
tachycardia.

Warfarin When healthy subjects were administered dronedarone 600 mg
twice daily, exposure to S-warfarin was higher than when warfarin
was administered alone (1.2-fold). Monitor INR closely after
initiating dronedarone in patients taking warfarin.

Drug Interactions with Sotalol:

Antiarrhythmics Class Ia antiarrhythmic drugs, such as disopyramide, quinidine and
procainamide and other Class III drugs (e.g., amiodarone) are not
recommended as concomitant therapy with Sotalol (Betapace),
because of their potential to prolong refractoriness.

Digoxin Concomitant use can increase the risk of bradycardia.

Insulin and oral Hyperglycemia may occur, and the dosage of insulin or antidiabetic
antidiabetics drugs may require adjustment. Symptoms of hypoglycemia may be
masked.

Clonidine Beta-blocking drugs may potentiate the rebound hypertension
sometimes observed after discontinuation of clonidine; therefore,
caution is advised when discontinuing clonidine in patients
receiving Sotalol (Betapace).

Antacids Administration of Sotalol (Betapace) within 2 hours of antacids
containing aluminum oxide and magnesium hydroxide should be
avoided because it may result in a reduction in Cmax and AUC of
26% and 20%, respectively and consequently in a 25% reduction in
the bradycardic effect at rest. Administration of the antacid two
hours after Sotalol (Betapace) has no effect on the pharmacokinetics
or pharmacodynamics of Sotalol.

Drug/Laboratory Test The presence of Sotalol (Betapace) in the urine may result in
Interactions falsely elevated levels of urinary metanephrine when measured by
fluorometric or photometric methods. In screening patients suspected
of having a pheochromocytoma and being treated with sotalol, a
specific method, such as a high performance liquid chromatographic
assay with solid phase should be used for determining levels of
catecholamines.

18