Antimicrotubules

Question 1

types of antimicrotubules

Answer 1

Inhibition of Polymerization
- Colchicine
- Vinca alkaloids
(vincristine, VInblastine, vinorelbine)

Inhibition of Depolymerization:
- Taxanes

Question 2

MOA of antimicrotubule

Answer 2

MOA: Binds to tubulin, a protein that compromised of alpha and beta subunits, inhibit its polymerization. (Polymerization of tubulin is responsible for the formation of the mitotic spindle during the metaphase period of mitosis)

Question 3

Vinca-Induced Toxicities

Answer 3

In general..
•All vincas have very low emetogenic potential! •Vesicants!
•Alopecia

Question 4

Vincristine toxicities

Answer 4

Vincristine
•Peripheral neuropathy: maximum dose is 2 mg weekly •Ileus, constipation
•Rarely causes bone marrow suppression

Question 5

Vinblastine and Vinorelbine toxicities

Answer 5

Vinblastine and Vinorelbine
•Dose limiting neutropenia and thrombocytopenia
•Neurologic toxicity and constipation can also occur but much lesst han vincristine

Question 6

When should we adjust dose if pt take vinca alkaloid?

Answer 6

• ## MUST adjust doses when patient experiences hepatic dysfunction!

Question 7

Vinca alkaloid interaction cyp

Answer 7

Many drug interactions (substrate for CYP3A4)

Question 8

Antidote for vesicant effect in vinca alkaloid

Answer 8

• Agents are potent vesicants, apply warm pack and administer hyaluronidase 1ml as an antidote

Question 9

__________ administration of vinca alkaloid is fatal.

Answer 9

Intrathecal administration of these agents is FATAL

Question 10

Taxanes MOA

Answer 10

Mechanism of action: similar to vincas; except the taxanesbind preferentially to the microtubules shifting the microtubules towards polymerization –the taxanesthen stabilize against depolymerization

Question 11

Taxanes require ___________________

Answer 11

Premedications Required for Taxanes

Question 12

taxanes drugs

Answer 12

(Paclitaxel, Docetaxel, Ixabepilone)

Question 13

Premedication for Paclitaxel

Answer 13

Paclitaxel (Taxol®, Anzatax®)

• PREMEDICATIONS for Hypersensitivity
• Give H1-blocker, H2-blocker, Corticosteroids
• If given Albumin stabilized anoparticle version (Abraxane®) –no premed required !

Question 14

Premed for Docetaxel

Answer 14

Docetaxel(Taxotere®)

• PREMEDICATIONS for Edema
• Give Dexamethasone starting on the day before chemo

Question 15

premed for Ixabepilone

Answer 15

Ixabepilone (Ixempra®)

• PREMEDICATIONS for Hypersensitivity
• Give H1 and H2 blockers: Diphenhydramine 50 mg and Ranitidine 150-300 mg PO 30 minutes before treatment

Question 16

Toxicities of taxanes

Answer 16

Toxicities (frequency of administration affect types of SE)

• Neuropathy
• Lacrimation
• Myalgia
• Arthralgia
• Fatigue
• Neutropenia
• Infection
• Stomatitis