A patient with hypertension and angina is referred for treatment. Metoprolol and verapamil are among the drugs considered. Both metoprolol and verapamil are associated with
which one of the following?
(A) Diarrhea
(B) Hypoglycemia
(C) Increased PR interval
(D) Tachycardia
(E) Thyrotoxicosis�
(C) Increased PR interval
Both metoprolol and verapamil can cause increased PR interval, although they work through different mechanisms. Metoprolol is a beta-blocker that can slow down the electrical conduction in the heart, leading to prolongation of the PR interval. Verapamil is a calcium channel blocker that can also prolong the PR interval by slowing down conduction through the AV node.