Topotec 2.5 mg Injection

Side Effects of Topotec 2.5 mg Injection

Neutropenia (nadir of white cell count occurs about 9-12 days after admin), thrombocytopenia and anaemia. GI upset, total alopecia, headache, dyspnoea. Fatigue, weakness, malaise, pruritus and hyperbilirubinaemia.

Drug Interactions

Increased clearance with phenytoin. G-CGF to be given 24 hr after completion of treatment with topotecan as concurrent admin may prolong duration of neutropenia. Increased bone marrow supression with other cytotoxic drugs (e.g. cisplatin) so dose reduction may be needed.

Contraindications

Severe bone marrow depression (e.g. baseline neutrophil count of <1500 cells/mm3 and platelet count <100,000/mm3). Pregnancy, lactation, severe renal or hepatic impairment.

Mechanism of Action

Topotecan, an alkaloid, is a semi-synthetic derivative of camptothecin which inhibits topoisomerase I, preventing DNA replication and translocation. It acts in the S phase of DNA synthesis. Distribution: Widely distributed. Protein-binding: 35%. Terminal half-life: 2-3 hr. Metabolism: Undergoes reversible hydrolysis to inactive hydroxy acid form; small amounts demethylated in the liver. Excretion: Excreted in urine.

Special Precautions

Preexisting bone marrow depression. Frequent monitoring of peripheral blood cell counts during treatment. Do not continue subsequent courses until neutrophils recover to >1000 cells/mm3, platelets recover to >100,000 cells/mm3 and haemoglobin levels recover to 9.0 g/dl (with transfusion if needed). May impair ability to drive or operate machinery.

How to Use

Take orally with food and water, as directed by your physician.

How to Store

Keep in a cool, dry place away from sunlight and moisture.

Safety Concerns

• Alcohol: Avoid during treatment.
• Breastfeeding: Not recommended.
• Pregnancy: Contraindicated.
• Liver/Kidney: Use with caution.

Content Disclaimer

This content is for educational purposes only. Please consult your doctor before use.