Dextromethorphan and quinidine and Itraconazole interaction

QT Prolongation: Monitor ECG if concomitant use of drugs that prolong QT interval cannot be avoided or if concomitant CYP3A4 inhibitors used.

This includes patients concomitantly taking/initiating drugs that prolong the QT interval or that are strong or moderate CYP3A4 inhibitors, and patients with left ventricular hypertrophy (LVH) or left ventricular dysfunction (LVD).

Drugs that Prolong QT and Concomitant CYP3A4 Inhibitors Recommend ECG in patients taking drugs with NUEDEXTA that prolong the QT interval and in patients taking concomitant moderate or strong CYP3A4 inhibitors [ see Warnings and Precautions ( 5.3 ) ] .

Strong and moderate CYP3A inhibitors include, but are not limited to, atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, amprenavir, aprepitant, diltiazem, erythromycin, fluconazole, fosamprenavir, grapefruit juice, and verapamil.

Digoxin Quinidine is an inhibitor of P-glycoprotein.

Cardiac Dysrhythmias Life-threatening cardiac dysrhythmias and/or sudden death have occurred in patients using drugs such as, pimozide, methadone, or quinidine concomitantly with oral itraconazole and/or other CYP3A4 inhibitors.

Several of these reports included concurrent administration of quinidine which is contraindicated [see Boxed Warning , Contraindications (4.2) and Drug Interactions (7) ] .

Antiarrhythmics Disopyramide Dofetilide Dronedarone Quinidine Contraindicated during and 2 weeks after TOLSURA treatment.

Co-administration with eliglustat is contraindicated in poor or intermediate metabolizers of CYP2D6 and in subjects taking strong or moderate CYP2D6 inhibitors.

…and Drug Interactions (7.1) ] Co-administration with colchicine, fesoterodine and solifenacin is contraindicated in subjects with varying degrees of renal or hepatic impairment, and Co-administration with eliglustat is contraindicated in subjects that are poor or intermediate metabolizers of CYP2D6 and in subjects taking strong or moderate CYP2D6 inhibitors.