Topoxin

• Small Cell Lung Cancer: Used in combination with other approved chemotherapeutic agents as first-line treatment.
• Testicular Cancer: Used for treatment of testicular cancer.

Etoposide is a semisynthetic derivative of podophyllotoxin used in the treatment of certain neoplastic diseases. Podophyllotoxins inhibit mitosis by blocking microtubular assembly. Etoposide inhibits cell cycle progression at a premitotic phase (late S and G2).

Adult Dose (IV):

• Testicular Cancer: 50-100 mg/m²/day IV on days 1-5, OR 100 mg/m²/day IV on days 1, 3, 5; repeat q3-4week.
• Small-Cell Lung Cancer: 35 mg/m²/day IV for 4 days, OR 50 mg/m²/day IV for 5 days; repeat q3-4week.
• Oral (Small cell lung cancer): Twice the IV dose, rounded to the nearest 50 mg.

Renal Dose: CrCl >50 mL/min: No adjustment; CrCl 15-50 mL/min: 75% of regular dose.

Common Side Effects:

• Anemia (low number of red blood cells)
• Decreased blood cells (red cells, white cells, and platelets)
• Decreased white blood cell count
• Diarrhea
• Hair loss
• Liver damage
• Low blood platelets
• Nausea
• Rash
• Stomatitis (Inflammation of the mouth)
• Vomiting

Hematologic Toxicity: Myelosuppression is dose related and dose limiting; granulocyte nadirs 7-14 days, platelet nadirs 9-16 days.

Use in Pregnancy: Category D; unsafe due to definite evidence of risk to the developing baby.

Precautions:

• Etoposide does not usually affect your ability to drive.
• Frequent observation for myelosuppression during and after therapy required.
• Platelet count below 50,000/mm3 or ANC below 500/mm3: withhold further therapy.
• Risk of anaphylactic reaction (chills, fever, tachycardia, bronchospasm, dyspnea, hypotension).
• Administer only by slow intravenous infusion (30-60 minutes).
• In severe reactions, reduce dose or discontinue.
• Caution in liver and kidney disease.

Overdose: Limited information; overdose may cause myelosuppression; symptomatic treatment.

Storage: Store under refrigeration 2-8 degree C. Protect from light. Keep out of reach of children.