Drug Interactions between dexamethasone / moxifloxacin and ensartinib

MONITOR CLOSELY: Concomitant administration of corticosteroids may potentiate the risk of tendinitis and tendon rupture associated with fluoroquinolone treatment. The mechanism is unknown. Tendinitis and tendon rupture have most frequently involved the Achilles tendon, although cases involving the rotator cuff (the shoulder), the hand, the biceps, and the thumb have also been reported. Some have required surgical repair or resulted in prolonged disability. Tendon rupture can occur during or up to several months after completion of fluoroquinolone therapy.

MANAGEMENT: Caution is recommended if fluoroquinolones are prescribed in combination with corticosteroids, particularly in patients with other concomitant risk factors (e.g., age over 60 years; recipient of kidney, heart, and/or lung transplant). Patients should be advised to stop taking the fluoroquinolone, avoid exercise and use of the affected area, and promptly contact their physician if they experience pain, swelling, or inflammation of a tendon. In general, fluoroquinolones should only be used to treat conditions that are proven or strongly suspected to be caused by bacteria and only if the benefits outweigh the risks.

GENERALLY AVOID: Coadministration with moderate to potent inducers of CYP450 3A4 may decrease the plasma concentrations and pharmacologic effects of ensartinib, which is primarily metabolized via the isoenzyme in vitro. Clinical data characterizing the extent of this interaction and data with less potent inducers are not available.

MANAGEMENT: Concomitant use of ensartinib with moderate to potent inducers of CYP450 3A4 should generally be avoided. The possibility of diminished therapeutic effects should be considered. Consultation with package labeling and relevant institutional protocols may be advisable for further guidance.