Page 1176 - Basic _ Clinical Pharmacology ( PDFDrive )

1162 SECTION X Special Topics

TABLE 66–1 Important drug interactions.

Drug or Properties Promoting
Drug Group Drug Interaction Clinically Documented Interactions
Calcium channel Verapamil, diltiazem, and perhaps Amiodarone: [P] Decreased metabolism of calcium channel blockers. Enhanced effects
blockers nicardipine inhibit hepatic drug- on myocardial conduction with bepridil, diltiazem, and verapamil. Expect similar inter-
metabolizing enzymes (CYP3A4) actions with dronedarone.
and P-glycoprotein. Metabolism (via
CYP3A4) of diltiazem, felodipine, Antivirals: [P] Amprenavir, atazanavir, boceprevir, darunavir, delavirdine, fosamprenavir,
nicardipine, nifedipine, verapamil, indinavir, nelfinavir, ritonavir, saquinavir, simeprevir, and telaprevir inhibit the metabo-
and other calcium channel blockers lism of calcium channel blockers.
subject to induction and inhibition. Boceprevir: [P] Decreased metabolism of calcium channel blockers.
Carbamazepine: [P] Decreased carbamazepine metabolism with diltiazem and
verapamil; possible increase in calcium channel blocker metabolism.
Cimetidine: [NP] Decreased metabolism of calcium channel blockers.
Colchicine: [P] Decreased colchicine elimination with diltiazem, nicardipine, and
verapamil.
Conivaptan: [P] Decreased metabolism of calcium channel blockers.
Cyclosporine: [P] Decreased cyclosporine elimination with diltiazem, nicardipine,
verapamil.
Digitalis glycosides: [P] Decreased elimination of digitalis glycoside with bepridil,
diltiazem and verapamil.
Kinase inhibitors: [P] Decreased metabolism of calcium channel blockers with
ceritinib, dasatinib, imatinib, idelalisib, and lapatinib. Decreased metabolism of kinase
inhibitors by diltiazem, nicardipine, and verapamil.
Macrolide antibiotics: [P] Clarithromycin and erythromycin inhibit the metabolism of
calcium channel blockers.
Phenytoin: [P] Increased metabolism of calcium channel blockers.
Rifampin: [P] Increased metabolism of calcium channel blockers.
Sirolimus: [P] Decreased sirolimus elimination with diltiazem, nicardipine, verapamil.
Statins: [P] Decreased atorvastatin, lovastatin, and simvastatin elimination with
diltiazem, nicardipine, verapamil.
Tacrolimus: [P] Decreased tacrolimus elimination with diltiazem, nicardipine,
verapamil.
Theophylline: [P] Decreased theophylline metabolism with diltiazem, nicardipine, and
verapamil.
See also Azole antifungals; Barbiturates.
Carbamazepine Induction of hepatic microsomal Amiodarone: [P] Decreased metabolism of carbamazepine; increased metabolism of
drug-metabolizing enzymes amiodarone. Expect similar interactions with dronedarone.
and P-glycoprotein. Susceptible
to induction and inhibition of Antivirals: [P] Amprenavir, atazanavir, boceprevir, darunavir, delavirdine, fosamprenavir,
metabolism, primarily by CYP3A4. indinavir, nelfinavir, ritonavir, saquinavir, simeprevir, and telaprevir inhibit the
metabolism of carbamazepine. Increased metabolism of antivirals by carbamazepine.
Cimetidine: [P] Decreased carbamazepine metabolism.
Corticosteroids: [P] Increased corticosteroid metabolism.
Cyclosporine: [P] Increased cyclosporine metabolism and possible decreased
carbamazepine metabolism.
Danazol: [P] Decreased carbamazepine metabolism.
Digitalis glycosides: [P] Increased digoxin elimination.
Fluvoxamine: [NE] Decreased carbamazepine metabolism.
Estrogens: [P] Increased estrogen metabolism.
E, Expected; HP, Highly predictable. Interaction occurs in almost all patients receiving the interacting combination; P, Predictable. Interaction occurs in most patients receiving the
combination; NP, Not predictable. Interaction occurs only in some patients receiving the combination; NE, Not established. Insufficient data available on which to base estimate
of predictability.
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