Topotecan Pharmacology


About Topotecan
A topoisomerase I inhibitor, Natural Source (Plant) Derivative, Antineoplastic.
Mechanism of Action of Topotecan
This antineoplastic drug inhibits the action of enzyme topoisomerase 1(this enzyme produces reversible single strand breaks in DNA during DNA replication) by binding to it. This results topoisomeras1-DNA complex and prevents the relegation of DNA strand, resulting in double strand DNA breakage and cell death. The drug has also radiation-sensitizing ability.
Pharmacokinets of Topotecan
Absorption- Rapidly absorbed after intravenous administration.
Distribution- Widely distributed in the body.35% bound to the plasma proteins.
Metabolism- Metabolized by reversible pH dependant hydrolysis of its lactone moiety (active part) to inactive hydroxyl acid form. A small portion is metabolized in the liver to active N-demethyl topotecan.
Excretion- Excreted via bile and urine (20-60%).
Onset of Action for Topotecan
Duration of Action for Topotecan
Half Life of Topotecan
Side Effects of Topotecan
1. Nausea
2. Vomiting
3. Lowered resistance to infection
4. Bruising or unusual bleeding
5. Anemia
6. Weakness
7. Sore in mouth
8. Taste changes
9. Diarrhea
10. Loss of appetite
11. Visual changes
12. Black, tarry stools
13. Blood in urine or in stool
14. Cough or hoarseness
15. Fever
16. Chills
17. Lower back or side pain
18. Painful or difficult urination
19. Pinpoint red spot on skin
20. Slurred speech
21. Swelling on leg or lower leg
22. Shortness of breath
23. Bloody vomiting
24. Thinned or brittle hair
25. Mouth blistering
26. Thrombocytopenia
27. Leucopenia
28. Tachycardia
29. Bradycardia
30. Chest pain
31. Hypertension
32. Myalgia
33. Alopecia
34. Intestinal obstruction
35. Stomatitis
36. Asthenia
37. Elevations of liver enzymes
38. Dyspnoea
39. Sepsis

Contra-indications of Topotecan
1. Hypersensitivity to the drug
2. Severe bone marrow suppression
Special Precautions while taking Topotecan
1. Cautiously used in patients with renal dysfunction
Pregnancy Related Information
Old Age Related Information
Use with caution
Breast Feeding Related Information
Children Related Information
Use with caution
Indications for Topotecan
1. Ovarian cancer
2. Lung cancer
3. Chronic myelomonocytic leukemia (CMML)
4. Myelodysplastic syndrome (MDS)
5. Glioma
6. Multiple myeloma
7. Neuroblastoma
8. Pancreatic cancer
9. Rhabdomyosarcoma
10. Ewing`s sarcoma
Interactions for Topotecan
Other anti neoplastic agents: Myelosuppression may be more severe if topotecan is given with cisplatin.
G-CSF: Coadministration of G-CSF and topotecan may prolong duration of neutropenia. If G-CSF has to be used, it should be started only on day 6 of the course i.e., 24 hr. after completion treatment with topotecan.

Typical Dosage for Topotecan
Ovary cancer: 1.5mg/metre square/day over 30 minutes for 5 consecutive days, starting on day 1 of a 21 day cycle -
Lung cancer: 1.5mg/metre square over 30 minutes daily for 5 consecutive days. Then follows the treatment for 21 days after 16 days rest
Schedule of Topotecan
Storage Requirements for Topotecan
Stored at 2 -8 degree C. Protect from light and humidity.
Effects of Missed Dosage of Topotecan
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Topotecan
Give symptomatic and supportive treatment.

Home Delivery for Topotecan in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including topotecan.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for topotecan and other medicines and health products. Home delivery services for topotecan may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take topotecan only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for topotecan before they complete the sale. You can get this information while placing the order for topotecan with the pharmacy.

Topotecan is a generic medicine name and there are several brands available for it. Some of the brands for topotecan might be better known than topotecan itself. If the pharmacy that's willing to deliver medicines to your home doesn't have topotecan in stock, you can ask for one of the branded alternatives for topotecan.