Drug Interaction Report

MONITOR: Coadministration with talquetamab may increase the plasma concentrations of drugs that are substrates of CYP450 isoenzymes. Treatment with talquetamab causes release of cytokines that may suppress the activity of CYP450 isoenzymes, although the potential for interactions has not been studied. According to the manufacturer, the highest drug-drug interaction risk would likely be observed from the initiation of talquetamab up to 14 days after the first treatment dose as well as during and after cytokine release syndrome.

MANAGEMENT: Caution is advised when talquetamab is coadministered with drugs that are primarily metabolized by CYP450 isoenzymes, particularly those with a narrow therapeutic index (e.g., antiarrhythmics, anticonvulsants, immunosuppressants, theophylline, warfarin) or sensitive substrates where increases in plasma levels may be substantial or undesirable (e.g., antineoplastic agents, benzodiazepines, ergot alkaloids, opioids, statins). Clinical and/or laboratory monitoring should be considered following the initiation or withdrawal of talquetamab, and the individual dosage of the concomitant agents may be adjusted as needed.

GENERALLY AVOID: Grapefruit juice may significantly increase the plasma concentrations of orally administered everolimus. The mechanism is inhibition of CYP450 3A4 and P-glycoprotein activity in the gut wall by certain compounds present in grapefruit.

MANAGEMENT: Patients treated with everolimus should avoid consumption of grapefruit and grapefruit juice.