Ivabradine: Increased plasma conc w/ potent CYP3A4 inhibitors (eg, ketoconazole, itraconazole, clarithromycin, erythromycin per os, josamycin, telithromycin, nelfinavir, ritonavir, & nefazodone). Decreased plasma conc w/ CYPA 3A4 inducers. Increased exposure w/ & additional heart rate reduction of 5 bpm w/ diltiazem, verapamil. Increased risk of AV conduction disturbances w/ diltiazem & verapamil; grapefruit juice. Exacerbated QT prolongation w/ quinidine, disopyramide, bepridil, sotalol, ibutilide & amiodarone; pimozide, ziprasidone, sertindole, mefloquine, halofantrine, pentamidine, cisapride, IV erythromycin. Concomitant use w/ fluconazole. Decreased exposure w/ Hypericum perforatum
(St John's Wort). Risk of severe arrhythmias w/ K-depleting diuretics (thiazide & loop diuretics). Carvedilol: Concomitant treatment w/ CYP 450 inhibitors (eg, cimetidine, fluoxetine, verapamil, ketoconazole, haloperidol, erythromycin). Potential increased β-blockade w/ quinidine, disopyramide, bepridil, sotalol, ibutilide & amiodarone; pimozide, ziprasidone, sertindole, mefloquine, halofantrine, pentamidine, cisapride, IV erythromycin. Risk of heart failure w/ IV class Ia or Ic antiarrhythmic agents. Reduced plasma conc w/ rifampicin. Increased AUC w/ cimetidine. Increased conc of digoxin & digitoxin; cyclosporine. Enhanced blood glucose-lowering effects of insulin & oral anti-diabetic medicines. Concomitant use w/ Catecholamine-depleting agents (eg, reserpine, guanethidine, methyldopa, guanfacine & MAOIs). May potentiate BP & heart rate lowering effects w/ clonidine. Reports of heart failure & severe hypotension w/ dihydropyridine. Synergistic, negative, inotropic & hypotensive effects w/ anesth. Antagonized bronchodilatory effects of β-agonist bronchodilators. May potentiate antihypertensive effects of α1-receptor antagonists. Increased BP & ability to control BP w/ NSAIDs. Reduced antihypertensive activity w/ estrogen & corticosteroids. Increased hypotensive effect w/ nitrates. Increased risk of hypotension & excessive bradycardia w/ sympathomimetics w/ α-mimetic & β-mimetic effects. Increased vasoconstriction w/ ergotamine. Increased neuromuscular block w/ neuromuscular blocking agents. Increased adverse effects w/ β-blockers in the form of eye drops. Reduced efficacy w/ barbiturates.