Drug Interaction Report

GENERALLY AVOID: The risk and/or severity of diarrhea may be increased when idelalisib is used with other agents that cause diarrhea. In premarketing trials, serious and fatal diarrhea or colitis (Grade 3 or higher) occurred in 14% of patients receiving idelalisib. Diarrhea may occur at any time and responds poorly to antimotility agents. The median time to resolution across trials ranged from one week to one month following interruption of idelalisib therapy and, in some instances, use of corticosteroids. Serious and fatal intestinal perforation has also been reported with idelalisib. At the time of perforation, some patients had moderate to severe diarrhea.

MANAGEMENT: Concomitant use of idelalisib with other drugs that cause diarrhea should be avoided whenever possible. Patients treated with idelalisib should be monitored for development of severe diarrhea or colitis during treatment in accordance with the product labeling, and the dosing adjusted or interrupted as necessary. Permanent discontinuation of idelalisib is recommended in those who experience life-threatening diarrhea or intestinal perforation. Patients should be advised to contact their physician immediately if the number of bowel movements per day increases by six or more, and to promptly report any new or worsening abdominal pain, chills, fever, nausea, or vomiting.