Substrate of CYP 3A4. Evidence speaks against capacity for significant irreversible CYP-inhibition. No observations of CYP-induction. However side effects such as anorexia, nausea and vomiting may be potentially porphyrinogenic through reduction in caloric intake.

Vinblastine is a naturally occurring vinca alkaloid. Vinblastine sulfate is the freely watersoluble and highly hygroscopic sulphate salt of a dimeric alkaloid isolated from Cantharanthus roseus.

Vinblastine sulfate is an antimicrotubule antineoplastic agent used in the treatment of Hodgkins disease and other lymphomas, for some inoperable malignant neoplasms including those of the breast, bladder, and kidney, and in non-small cell lung cancer, choriocarcinoma, and Kaposis sarcoma. It is usually given with other antineoplastics, and is administered intervenously, not more often than once a week. Common adverse reactions of vinblastine that can be confused with an acute porphyric attack are nausea, vomiting, abdominal pain, and obstipation. Peripheral neuropathy, paraesthesia, loss of deep tendon refelexes are less common. Side effects such as anorexia, nausea and vomiting may be potentially porphyrinogenic through reduction in caloric intake.

Vinblastine is metabolised in the liver by CYP 3A4 to desacetylvinblastine, which is excreted mainly via bile. Administered as watersoluble sulphate salt with low PXR affinity. Listed as substrate and inhibitor of CYP3A4 by Rendic (2002), Zhou (2007) and Baumhakel (2001), however the concentrations of vinblastine required for a 50 % inhibition of vinblastine is 10 times higher those occuring during treatment (Baumhakel, 2001)(Fischer, 1998). No observations of interference with CYP-metabolism of other drugs.

Reports of uneventful use: Arbus (1981) reported uneventful use of vinblastine to treat testicular cancer in a male AIP-patient.