Drug Interaction Report

GENERALLY AVOID: Panobinostat can cause dose-dependent 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 a premarketing multiple myeloma trial, QTc prolongation with values between 451 to 480 msec and between 481 to 500 msec occurred in 10.8% and 1.3% of patients receiving panobinostat, respectively. A maximum QTcF increase from baseline of 31 to 60 msec and greater than 60 msec was observed in 14.5% and 0.8% of panobinostat-treated patients, respectively. No episodes of QTcF prolongation exceeding 500 msec were reported with panobinostat given at a dose of 20 mg in combination with bortezomib and dexamethasone in the multiple myeloma trial. Pooled clinical data from over 500 patients treated with panobinostat monotherapy at different dose levels for various indications have shown that the incidence of CTC Grade 3 QTc prolongation (i.e., QTcF >500 msec) was approximately 1% overall and 5% or more at a dose of 60 mg or higher. 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, hypocalcemia). Moreover, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: Concomitant use of panobinostat with other drugs that can prolong the QT interval should generally be avoided. Anti-emetic drugs with known QT prolonging risk such as dolasetron, granisetron, ondansetron, palonosetron, and tropisetron may be used with frequent ECG monitoring. ECG and serum electrolytes, including potassium, magnesium and calcium, should be monitored before starting panobinostat therapy and periodically during treatment as clinically indicated. In the premarketing trial, ECGs were performed at baseline and prior to initiation of each cycle for the first 8 cycles. Panobinostat should not be started if baseline QTc is greater than 450 msec. Likewise, treatment should be interrupted in patients who develop QTc prolongation of 480 msec or greater until recovery to less than or equal to Grade 1, then resumed at a reduced dose. In case of recurrence, therapy should be withheld until recovery to less than or equal to Grade 1, then resumed at a further reduced dose if necessary. Permanently discontinue panobinostat therapy if Grade 3 or 4 QTc prolongation does not resolve. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

ADJUST DOSE: The central nervous system and respiratory depressant effects of meperidine may be potentiated by concomitant use of other agents with CNS depressant effects. An increased risk of serious adverse reactions such as respiratory depression, hypotension, profound sedation, syncope, coma, and even death should be considered, particularly in elderly or debilitated patients.

MANAGEMENT: Caution and dosage adjustments are advisable when meperidine is used in combination with other narcotic analgesics, general anesthetics, phenothiazines, sedative-hypnotics, tranquilizers, tricyclic antidepressants, or other CNS depressants such as alcohol. A lower dosage of meperidine should be considered initially, then titrated carefully according to pain level and clinical response. Meperidine dosage reductions of 25% to 50% have been recommended for patients receiving phenothiazines and other tranquilizers. Patients should be advised to avoid rising abruptly from a sitting or recumbent position, and to notify their physician if they experience dizziness, lightheadedness, orthostasis, syncope, tachycardia, or excessive CNS effects that interfere with their normal activities. Patients should also avoid driving or operating hazardous machinery until they know how these medications affect them.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of panobinostat. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Increased exposure to panobinostat may increase the risk of adverse effects such as nausea, vomiting, diarrhea, anorexia, peripheral edema, cardiotoxicity, ECG abnormalities, electrolyte disturbances, bleeding complications, hepatotoxicity, and myelosuppression.

Food may delay the rate of absorption of panobinostat, but does not significantly affect the overall extent of absorption. When a single oral dose of panobinostat was administered to 36 patients with advanced cancer 30 minutes after a high-fat meal, panobinostat peak plasma concentration (Cmax) and systemic exposure (AUC) were approximately 44% and 16% lower, respectively, compared to administration under fasting conditions. The median time to maximum concentration (Tmax) was prolonged by 2.5 hours.

MANAGEMENT: Patients should avoid consumption of grapefruit or grapefruit juice during treatment with panobinostat. The manufacturer also recommends avoiding star fruit, Seville oranges, pomegranate, and pomegranate juice. Panobinostat may be administered with or without food.

GENERALLY AVOID: Ethanol may potentiate the central nervous system (CNS) depressant effects of opioid analgesics. Concomitant use may result in additive CNS depression and impairment of judgment, thinking, and psychomotor skills. In more severe cases, hypotension, respiratory depression, profound sedation, coma, or even death may occur.

MANAGEMENT: Concomitant use of opioid analgesics with ethanol should be avoided.

GENERALLY AVOID: Concurrent use of ethanol and phenothiazines may result in additive CNS depression and psychomotor impairment. Also, ethanol may precipitate dystonic reactions in patients who are taking phenothiazines. The two drugs probably act on different sites in the brain, although the exact mechanism of the interaction is not known.

MANAGEMENT: Patients should be advised to avoid alcohol during phenothiazine therapy.