Drug Interactions between buprenorphine and Quinidex Extentabs

GENERALLY AVOID: Buprenorphine administered transdermally at a higher than recommended dosage has been associated with prolongation of the QT interval. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. In healthy volunteers, there was no difference in the effect of buprenorphine 10 mcg/hr administered transdermally on the QT interval compared to placebo. However, buprenorphine 40 mcg/hr (twice the maximum recommended dosage) was associated with a mean prolongation of the QT interval of 5.9 msec compared to placebo. Buprenorphine 20 mcg/hr was not studied. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: According to the product labeling, use of buprenorphine transdermal films should be avoided in patients treated with class IA (e.g., disopyramide, quinidine, procainamide) or class III (e.g., amiodarone, dofetilide, sotalol) antiarrhythmic agents. A dosage of 20 mcg/hr should not be exceeded in patients receiving the buprenorphine transdermal system. Patients should be advised to seek medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, palpitations, or syncope.