Drug Interaction Report

MONITOR CLOSELY: According to the package labeling, patients receiving temsirolimus in combination with anticoagulation therapy may be at increased risk of developing intracerebral bleeding, including fatal outcomes. The mechanism of interaction has not been described.

MANAGEMENT: Patients receiving anticoagulants should be informed of the increased risk of developing intracerebral bleeding while on temsirolimus.

GENERALLY AVOID: Coadministration of temsirolimus with grapefruit juice may increase the plasma concentrations of sirolimus, a major active metabolite of temsirolimus and known substrate of CYP450 3A4. The proposed mechanism is inhibition of CYP450 3A4-mediated metabolism by certain compounds present in grapefruits.

MANAGEMENT: Patients treated with temsirolimus should preferably avoid the consumption of grapefruit or grapefruit juice.