MITOTIC SPINDLE INHIBITORS
| A | Taxol | |
| B | Vincristine | |
| C | Etoposide | |
| D | Irinotectan |
| A | Taxol | |
| B | Vincristine | |
| C | Etoposide | |
| D | Irinotectan |
Vincristine
Which of the following chemotherapeutic agents is specific for the M phase of the cell cycle?
| A |
Cytarabine |
|
| B |
Daunorubicin |
|
| C |
Hydroxyurea |
|
| D |
Vincristine |
Which of the following chemotherapeutic agents is specific for the M phase of the cell cycle?
| A |
Cytarabine |
|
| B |
Daunorubicin |
|
| C |
Hydroxyurea |
|
| D |
Vincristine |
Which one of the following statements is false regarding vincristine –
| A |
It is an alkaloid |
|
| B |
Its use is associated with neurotoxicity |
|
| C |
It does not cause alopecia |
|
| D |
It is a useful drug for induction of remission in acute lymphoblastic leukaemia |
Which one of the following statements is false regarding vincristine –
| A |
It is an alkaloid |
|
| B |
Its use is associated with neurotoxicity |
|
| C |
It does not cause alopecia |
|
| D |
It is a useful drug for induction of remission in acute lymphoblastic leukaemia |
Ans. is ‘c’ i.e., It does not cause alopecia
o Vincristine belongs to the plant alkaloid group of anticancer.
o Useful for inducing remission in childhood ALL (not useful in maintenance therapy)
o It can also be used for pediatric solid tumors (Wilm’s tumor, neuroblastoma, rhabdomyosarcoma) and lymphomas.
o Prominent adverse effects‑
o Peripheral neuropathy
Alopecia
SIADH
Peripheral neuropathy as a side effect is caused by which of the following anti cancer drugs ‑
| A |
Vincristine |
|
| B |
Cyclophosphamide |
|
| C |
Etoposide |
|
| D |
Irinotecan |
Peripheral neuropathy as a side effect is caused by which of the following anti cancer drugs ‑
| A |
Vincristine |
|
| B |
Cyclophosphamide |
|
| C |
Etoposide |
|
| D |
Irinotecan |
Ans. is ‘a’ i.e., Vincristine
About vinca alkaloids true is ‑
| A |
Inhibits mitotic spindle |
|
| B |
Enhances polymerization of tubulin |
|
| C |
Inhibits topoisomerase I |
|
| D |
Inhibits topoisomerase II |
About vinca alkaloids true is ‑
| A |
Inhibits mitotic spindle |
|
| B |
Enhances polymerization of tubulin |
|
| C |
Inhibits topoisomerase I |
|
| D |
Inhibits topoisomerase II |
Ans. is ‘a’ i.e., Inhibits mitotic spindle
Vinca alkaloids (vincristine) inhibit mitotic spindles by preventing polymerization of tubulin
Antimitotic drugs of plant source is/are‑
| A |
Vincristine |
|
| B |
Isotretinoin |
|
| C |
Bleomycine |
|
| D |
Methotraxate |
Antimitotic drugs of plant source is/are‑
| A |
Vincristine |
|
| B |
Isotretinoin |
|
| C |
Bleomycine |
|
| D |
Methotraxate |
Ans. is ‘a’ i.e., Vincristine
SIADH is associated with the following drug :
| A |
Vincristine |
|
| B |
Erythromycin |
|
| C |
5 – FU |
|
| D |
Methotrexate |
SIADH is associated with the following drug :
| A |
Vincristine |
|
| B |
Erythromycin |
|
| C |
5 – FU |
|
| D |
Methotrexate |
Answer is A (Vincristine):
Vincristine is known to cause SIADH.
Drugs associated with SIADH :
- Vasopressin or desmopressin
- Chlorpropamide
- Oxytocin, high dose
- Vincristine
- Carbamezapine
- Nicotine
- Phenothiazines
- Cyclophosphamide
- Tricyclic antidepressants
- M40 inhibitors
- Serotonin reuptake inhibitors
Mechanism of action of paclitaxel is ‑
| A |
Topoisomerase inhibition |
|
| B |
Increase the polymerization of tubulin |
|
| C |
Inhibition of protein synthesis |
|
| D |
Alkylation of DNA |
Mechanism of action of paclitaxel is ‑
| A |
Topoisomerase inhibition |
|
| B |
Increase the polymerization of tubulin |
|
| C |
Inhibition of protein synthesis |
|
| D |
Alkylation of DNA |
Ans. is ‘b’ i.e., Increase the polymerization of tubulin
Taxanes
- Paclitaxel and docetaxel function as a mitotic spindle poison through high affinity binding to microtubules with enhancement of tubulin polymerization.
- The microtubules are stabilized and their depolymerization is prevented → inhibition of mitosis and cell division.
- Paclitaxel is metabolized in liver and undergoes enterohepatic circulation → dose should be reduced in liver dysfunction.
- Paclitaxel can cause hypersensivity reaction which does not occur with a novel albumin-bound paclitaxel preparation.
- Paclitaxel and docetaxel both can cause bone marrow depression & peripheral neuropathy.
Peripheral neuropathy as a side effect is caused by which of the following anti cancer drugs ‑
| A |
Vincristine |
|
| B |
Cyclophosphamide |
|
| C |
Etoposide |
|
| D |
Irinotecan |
Peripheral neuropathy as a side effect is caused by which of the following anti cancer drugs ‑
| A |
Vincristine |
|
| B |
Cyclophosphamide |
|
| C |
Etoposide |
|
| D |
Irinotecan |
Ans. is ‘a’ i.e., Vincristine
Vincristine (Oncovin)
- Alkaloid derived from Vinca rosae.
- Vincristine belongs to the plant alkaloid group of anticancer.
- Rapidly acting anticancer
- This class of drugs are also known as spindle poison.
- These drugs bind to microtubular protein (tubulin)
- The drug-tubulin complex then attaches itself to microtubules and causes depolymerization of microtubules.
- Depolymerization of microtubule causes
- Mitotic arrest at metaphase
- Dissolution of mitotic spindle
- Interference with chromosome segregation
- Useful for inducing remission in childhood ALL (not useful in maintenance therapy)
- It can also be used for pediatric solid tumors (Wilm’s tumor, neuroblastoma, rhabdomyosarcoma) and lymphomas.
- Prominent adverse effects‑
Peripheral neuropathy Alopecia SIADH
- Vincristine is a marrow sparing drug but some times it may cause myelosuppression which is very less than vinblastin.
- Indications of vincristine‑
Hodgkins disease Wilms’s tumour Carcinoma lung
Non hodgkin:s. disease Ewing’s sarcoma Myeloma
- Vinblastine and vinorelbine are other vinca alkaloids.
- o Vinblastine’s most important clinical use is the curative therapy of metastatic testicular tumor.
- o Vinblastine can cause bone marrow suppression (in contrast with vincristin), alopecia, and nausea & vomiting. o As they arrest mitosis, all vinca alkaloids act in M phase.
