1–2 minutes
| Cycle Type | Drugs | Standard Doses |
|---|---|---|
| Odd cycles (A): 1,3,5,7 | Hyperfractionated Cyclophosphamide Vincristine Doxorubicin (Adriamycin) Dexamethasone | Cyclophosphamide 300 mg/m² IV q12h × 6 doses (days 1–3) Vincristine 2 mg IV days 4, 11 Doxorubicin 50 mg/m² IV day 4 Dexamethasone 40 mg PO/IV days 1–4, 11–14 |
| Even cycles (B): 2,4,6,8 | High-dose Methotrexate High-dose Cytarabine | Methotrexate 1 g/m² IV over 24h day 1 (with leucovorin rescue) Cytarabine 3 g/m² IV q12h × 4 doses days 2–3 (1 g/m² if age >60 or CrCl issues) |
| IT therapy | IT methotrexate and/or cytarabine | IT MTX 12 mg + IT Ara-C 100 mg each cycle; total CNS prophylaxis per protocol |
Leucovorin rescue (MTX cycles): MUST be on schedule. Typically leucovorin 15–25 mg PO/IV q6h starting 12–24h after MTX infusion completion until MTX level <0.05–0.1 µmol/L. Monitor MTX levels.
High-dose cytarabine (≥1 g/m²): Steroid eye drops (prednisolone 1% or dexamethasone) BID from day of cytarabine through 48h after LAST dose — prevents cytarabine-induced keratoconjunctivitis. NON-NEGOTIABLE.
Cytarabine dose reduction in elderly (>60 yrs) or renal impairment: reduce to 1 g/m² — severe neurotoxicity (cerebellar) risk.
Vincristine: 2 mg CAP (most institutions). Do NOT exceed 2 mg regardless of BSA. Peripheral neuropathy monitoring.
Doxorubicin: Cumulative lifetime dose limit (~450–550 mg/m²). Track running total. Baseline and serial ECHO.