Pharm

Topotecan

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Topotecan, Hycamtin

  • Indications
  1. FDA Approved (often combined with other agents)
    1. Ovarian Cancer
    2. Cervical Cancer
  2. Off-Label
    1. Acute Myelogenous Leukemia (AML)
    2. CNS Malignancy (including CNS Lymphoma)
    3. Ewing Sarcoma
    4. Neuroblastoma
    5. Ovarian Cancer (metastatic)
    6. Rhabdomyosarcoma
  • Mechanism
  1. See Mitotic Inhibitor Chemotherapy
  2. Irinotecan is a semisynthetic derivative of camptothecin with antineoplastic activity
    1. Camptothecin extracted from the Asian tree Camptotheca acuminata ("Happy Tree")
    2. Camptothecin is a cytotoxic quinoline-based alkaloid
  3. Topotecan is active without metabolism
    1. Contrast with Irinotecan, a similar drug, but that requires metabolism to SN-38 for activity
    2. Topotecan is considered less potent than SN-38, the active metabolite of Irinotecan
  4. Topotecan is a Topoisomerase Inhibitor
    1. Binds to topoisomerase 1, inhibiting DNA ligation
    2. DNA breaks accumulate
    3. Inhibits DNA Replication and transcription
    4. Arrests cell cycle in S phase
    5. Results in cell apoptosis and death
  • Medications
  1. Oral Capsules: 0.25 mg and 1 mg
  2. Powder for IV Injection Solution: 4 mg
  • Dosing
  1. See other references for disease specific dosing protocols
  • Adverse Effects
  1. Myelosuppression (Bone Marrow suppression)
    1. Neutropenia
  2. Bleeding (may be severe)
  3. Interstitial Lung Disease
  • Safety
  1. Avoid in Lactation
  2. Avoid in pregnancy (all trimesters)
    1. Use reliable Contraception (including one month after Chemotherapy completed)
  3. Monitoring
    1. Complete Blood Count
  • References
  1. Hamilton (2020) Tarascon Pocket Pharmacopoeia