Safe Co-Administration of Amenamevir with Calcineurin Inhibitors: Case Reports

Although co-administration of amenamevir (a helicase–primase inhibitor) reportedly decreases exposure to midazolam, a CYP3A4 substrate, it remains unclear whether induces the metabolism calcineurin inhibitors (tacrolimus and cyclosporine) metabolized by CYP3A4. Herein, we illustrated two cases induction for amenamevir. The concentration/dose normalized body weight was defined as inhibitors. first case is 63-year-old female (CYP3A5*3/*3 in both recipient donor) who received sustained-release tacrolimus 1.0 mg × 1 after living-donor liver transplantation. she temporarily withdrew on days 2 (from initiation combination), same dosage restarted from day 3. There no significant difference C/D ratio regardless 400 4 (day -16: 4.5 ng/mL, 277.2 ng/mL/mg/kg vs. 5: 3.6 221.8 ng/mL/mg/kg). second 71-year-old an therapy microemulsion cyclosporine 50 -2 nephrotic syndrome. genotype CYP3A5 unknown. Blood concentrations at h post-dose were 153.5 ng/mL (80.6 ng/mL/mg/kg) 166.8 (87.6 when administered 5 0. After discontinuation amenamevir, blood concentration 19 remained unchanged (170.4 89.5 In conclusion, co-administered ≤5 had less impact pharmacokinetics low concentrations.