Drug Interaction Report

MONITOR: Concomitant use of ashwagandha with other agents that are known to induce hepatotoxicity may theoretically increase the risk of hepatotoxicity. There are case reports of adverse effects on liver functions associated with ashwagandha use. In a case report, a 20-year-old man in Japan developed liver dysfunction and hyperbilirubinemia after using ashwagandha in combination with multiple antianxiety drugs. In additional case reports, three men and two women, age range 21 to 62 years who reportedly took supplements containing 450 to 1,350 mg ashwagandha daily over the course of one week to four months when signs of liver injury, such as jaundice, pruritus, nausea, lethargy, abdominal discomfort, and hyperbilirubinemia, appeared.

MANAGEMENT: Liver function tests should be monitored, and patients should be advised to report any symptoms such as abdominal pain, jaundice, dark urine, light stools, fever, or unusual fatigue.

GENERALLY AVOID: Grapefruit and Seville oranges may increase the plasma concentrations of lurbinectedin. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit and Seville oranges. Inhibition of hepatic CYP450 3A4 may also contribute. The interaction has not been studied with grapefruit or Seville oranges, but pharmacokinetic data are available for potent and moderate CYP450 3A4 inhibitors. In a clinical drug interaction study, coadministration of itraconazole, a potent CYP450 3A4 inhibitor, increased the systemic exposure (AUC) of total lurbinectedin by 2.7-fold and unbound lurbinectedin by 2.4-fold. In a Phase 1 study, coadministration of aprepitant, a moderate CYP450 3A4 inhibitor, decreased lurbinectedin plasma clearance by 33% compared to lurbinectedin alone. In general, the effect of grapefruit and Seville oranges is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice and Seville oranges (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Increased exposure may increase the incidence and severity of adverse reactions of lurbinectedin, such as myelosuppression and hepatotoxicity.

MANAGEMENT: Patients should avoid consumption of grapefruit, grapefruit juice, and Seville oranges during treatment with lurbinectedin.