methyl (1R,9R,10S,11R,12R,19R)-11-(acetyloxy)-12-ethyl-4-[(13S,15S,17S)-17-ethyl-17-hydroxy-13-(methoxycarbonyl)-1,11-diazatetracyclo[13.3.1.04,12.05,10]nonadeca-4(12),5,7,9-tetraen-13-yl]-8-formyl-10-hydroxy-5-methoxy-8,16-diazapentacyclo[10.6.1.01,9.02,7.016,19]nonadeca-2,4,6,13-tetraene-10-carboxylate

Absorption：Very rapidly absorbed via IV (15 to 30 min).

Distribution：More than 90% of drug is distributed from blood to tissue, where it remains tightly but not irreversibly. Penetration across the blood brain barrier is poor.

Metabolism：Triphasic serum decay following rapid IV injection.

Elimination：Terminal t ½ is 85 h (19 to 155 h). Liver is the major excretory organ. 80% of the dose appears in the feces, 10% to 20% in the urine.

Onset：15 to 30 min.

Special Populations：
Hepatic Function Impairment
A 50% reduction in dose is recommended for patients having a direct serum bilirubin more than 30mg/dL.

CYP-450 inhibitors
Vincristine elimination may be reduced by CYP-450 enzyme inhibitors.

Digoxin
May decrease digoxin plasma concentration.

Itraconazole
Vincristine neurotoxicity has occurred during coadministration.

L-asparaginase
Vincristine clearance may decrease when L-asparaginase is given prior to vincristine. Give vincristine 12 to 24 hr prior to L-asparaginase.

Mitomycin
Acute shortness of breath and severe bronchospasm have occurred following concomitant or previous use of mitomycin.

Phenytoin
May reduce phenytoin plasma concentration.

Quinolone antibiotics
Vincristine may decrease oral absorption of quinolone antibiotics.