Table 6.

Drug–Drug Interactions Among Study Subjects

Drug 1	Drug 2	Interaction Category	Description	Frequency
Metoprolol	Carvedilol	C	Increases the risk for bradycardia	1
Metoprolol	Diltiazem	C	Increases the risk for bradycardia	2
Gemfibrozil	Atorvastatin	X	Gemfibrozil may enhance the myopathic effect of atorvastatin	2
Fexofenadine	Loratadine	C	Both drugs have anticholinergic side effects and are CNS depressants	1
Regular insulin	Glimepiride	C	Increases the risk for hypoglycemia	2
Atenolol	Verapamil	C	Increases the risk for bradycardia
Candesartan	Spironolactone	C	Increases the risk of hyperkalemia	3
Amlodipine	Verapamil	C	Verapamil as CYP3A4 inhibitor may increase the serum concentration of Amlodipine	1
Bisoprolol	Verapamil	C	Increases the risk for bradycardia	3
Metoprolol	Diltiazem	C	Increases the risk for bradycardia	2
Dabigatran	Aspirin	D	Increases risk for bleeding	1