7 DRUG INTERACTIONS
7.1 Effect of Other Drugs on Voxelotor
Strong or Moderate CYP3A4 Inducers
Coadministration of strong or moderate CYP3A4 inducers may decrease voxelotor plasma and whole blood concentrations and may lead to reduced efficacy.
Avoid coadministration of OXBRYTA with strong or moderate CYP3A4 inducers. Increase the OXBRYTA dosage when coadministration with a strong or moderate CYP3A4 inducer is unavoidable [see Dosage and Administration (2.5, 2.6) and Clinical Pharmacology (12.3)].
7.2 Effect of Voxelotor on Other Drugs
Voxelotor increased the systemic exposure of midazolam (a sensitive CYP3A4 substrate) [see Clinical Pharmacology (12.3)]. Avoid coadministration of OXBRYTA with sensitive CYP3A4 substrates with a narrow therapeutic index. If concomitant use is unavoidable, consider dose reduction of the sensitive CYP3A4 substrate(s).
7.3 Laboratory Test Interference
OXBRYTA administration may interfere with measurement of Hb subtypes (HbA, HbS, and HbF) by HPLC [see Warnings and Precautions (5.2)]. If precise quantitation of Hb species is required, chromatography should be performed when the patient has not received OXBRYTA therapy in the immediately preceding 10 days.