Selumetinib Drug Interaction Dose Adjustment
Co-administration with Strong/Moderate CYP3A4 Inhibitors or Fluconazole
Principle: Avoid concomitant use whenever possible; if mandatory, reduce the dose. After discontinuing the inhibitor for 3 half‑lives, resume the original dose.
Dose Reduction Regimens
Original dose 25 mg/m²: reduce to 20 mg/m² (same as the "moderate hepatic impairment" regimen).
Original dose 20 mg/m²: reduce to 15 mg/m², as follows:
BSA 0.55–0.69 m²: 10 mg once daily
BSA 0.7–0.89 m²: 10 mg twice daily
BSA 0.9–1.09 m²: 20 mg in the morning + 10 mg in the evening
BSA 1.1–1.29 m²: 25 mg in the morning + 10 mg in the evening
BSA 1.3–1.49 m²: 25 mg in the morning + 20 mg in the evening
BSA 1.5–1.69 m²: 25 mg twice daily
BSA 1.7–1.89 m²: 30 mg in the morning + 25 mg in the evening
BSA ≥ 1.9 m²: 30 mg twice daily
Selumetinib Key Precautions
Contraindications: No absolute contraindications.
Age restriction: Safety and efficacy in children under 2 years of age have not been established.
Selumetinib Storage
Store in the original container (with desiccant), protect from moisture, at 15–30°C.
Selumetinib Monitoring
Cardiac: Monitor LVEF every 3 months during the first year of treatment, then every 6 months thereafter.
Skin: Monitor for severe rash.
Gastrointestinal: Monitor for diarrhoea symptoms.
Muscular: Regularly check CPK, watch for myalgia/muscle weakness.
Ophthalmologic: Regularly assess vision changes.
Drug interactions: Periodically review concomitant medications.
Reminders
1. Take on an empty stomach.
2. Effective contraception is required during treatment and for 1 week after stopping.
3. Report promptly any of the following: signs of heart failure, diarrhoea, vision changes, skin abnormalities, muscle pain/weakness.
4. Avoid vitamin E supplements.
