Streptozocin

• Class: Alkylating agent – Nitrosourea derivative (unique among nitrosoureas because of a sugar moiety).
• Mechanism of Action:
  • Alkylates DNA → induces cross-links and strand breaks → inhibits DNA replication and transcription.
  • Has a glucose-like moiety, leading to preferential uptake by pancreatic β-cells (islet cell specificity).
• Clinical Uses:
  • Pancreatic neuroendocrine tumors (islet cell carcinoma/insulinoma) – FDA approved.
  • Sometimes used in combination regimens (e.g., with 5-FU or doxorubicin) for advanced pancreatic NETs.
  • Limited role in other solid tumors due to toxicity.
• Dosing:
  • IV, various schedules:
    • 500 mg/m²/day for 5 days, every 6 weeks, or
    • 1000 mg/m² every 3 weeks.
  • Adjust for renal impairment.
• Toxicities:
  • Renal toxicity (dose-limiting) – cumulative, can cause irreversible renal failure.
  • Nausea/vomiting – highly emetogenic.
  • Hepatotoxicity (elevated LFTs, rare liver failure).
  • Myelosuppression (less severe than other nitrosoureas).
  • Glucose intolerance / hypoglycemia (rare, due to islet cell effects).
• Monitoring:
  • Renal function (serum creatinine, BUN, urinalysis, creatinine clearance) – before and during therapy.
  • CBC (though marrow toxicity is less pronounced).
  • Liver function tests.
  • Blood glucose (occasionally).

In summary:

Streptozocin is a nitrosourea alkylating agent with unique pancreatic islet cell tropism, mainly used in pancreatic neuroendocrine tumors. Its key concern is dose-limiting renal toxicity, making close monitoring essential.