55
5.2.6. Medication Interactions
Table 16. Pharmacokinetic Drug-Drug Interactions With
Antihypertensive Medications
Blood Pressure Drug
Potential
Interacting Drug Clinical Effect
Absorption
iazide-type diuretics Cholestyramine Decreased absorption leading to
reduced BP lowering
Amlodipine,
furosemide,
metoprolol, carvedilol,
bisoprolol, nebivolol,
telmisartan
Potassium binder
(patiromer)
Decreased absorption of
antihypertensives leading to reduced
BP-lowering effects. To mitigate this,
administer the antihypertensives at
least 3 h before or aer taking the
potassium binder
Furosemide Potassium binder
(sodium zirconium
cyclosilicate)
Increased absorption of furosemide
due to increased gastric pH leading
to increased clinical effects (eg,
diuresis or risk of hypokalemia);
effect diminished with separation of
administration by 2 h
Methyldopa Iron salts Decreased absorption of methyldopa
leading to reduced BP lowering
Metabolism
Bisoprolol, carvedilol,
metoprolol
CYP2D6 inhibitors
(eg, amiodarone,
cimetidine,
diphenhydramine,
fluoxetine, paroxetine,
terbinafine)
Increased BB concentration leading
to enhanced clinical effects (eg,
hypotension and bradycardia)
Diltiazem, verapamil CYP3A4 inhibitors
(eg, clarithromycin,
erythromycin
itraconazole,
ketoconazole)
Increased nondihydropyridine
concentration leading to enhanced
clinical effects (eg, hypotension and
bradycardia)
Diltiazem, verapamil CYP3A4 inducers
(eg, carbamazepine,
phenobarbital,
phenytoin, St. John's
Wort, rifampin)
Decreased nondihydropyridine
CCB concentration leading
to reduced clinical effects (eg,
minimization of blood pressure and
pulse lowering )
