DBL Vinblastine Drug Interactions

When chemotherapy is being given in conjunction with radiation therapy through portals which include the liver, the use of DBL Vinblastine Injection should be delayed until radiation therapy has been completed.
Vinblastine used as part of a combination regimen with mitomycin may result in fatal acute respiratory distress or failure and there have been cases of pulmonary infiltration or pulmonary oedema reported.
Cases of respiratory distress with interstitial pulmonary infiltrates have been reported in patients given a regimen comprising vinblastine, mitomycin, with or without progesterone (MVP). Acute shortness of breath and severe bronchospasm have been reported following the administration of the vinca alkaloids. These reactions have been encountered most frequently when the vinca alkaloid was used in combination with mitomycin-C and may be serious when there is pre-existing pulmonary dysfunction. The onset may be within minutes, or several hours after the vinca is injected, and may occur up to 2 weeks following a dose of mitomycin. Progressive dyspnoea, requiring chronic therapy, may occur. DBL Vinblastine Injection should not be re-administered.
The simultaneous administration of phenytoin and antineoplastic chemotherapy combinations that included vinblastine sulfate have been reported to reduce blood levels of the anticonvulsant and to increase seizure activity. Although the contribution of the vinca alkaloids has not been established, dosage adjustment of phenytoin, based on serial blood level monitoring, may need to be made when it is used in combination with vinblastine sulfate.
Co-administration of cisplatin has been reported to cause higher plasma concentrations of vinblastine and severity of neutropenia may be altered when given in conjunction with cisplatin.
Following combined treatment with vinblastine, bleomycin and cisplatin, there have been reports of a decline in glomerular filtration rate which may be reversible, nephrotoxicity, pulmonary toxicity, peripheral sensory neuropathy, neurotoxicity, ototoxicity, azoospermia, irreversible high frequency hearing loss, Raynaud's phenomenon with digital ischemia and gangrene, hypertension and other vascular events (such as myocardial infarction and cerebrovascular accident).
Erythromycin may increase the toxicity of vinblastine which may cause increased severity of neutropenia, myalgia and constipation.
Serum levels of anticonvulsants may be reduced by cytotoxic drug regimes, which include vinblastine.
Amenorrhea has occurred in some patients treated with vinblastine sulfate in combination with other drugs. Recovery of menses was frequent.
There is no currently available evidence to indicate that vinblastine sulfate itself has been carcinogenic in humans, although some patients have developed leukaemia following radiation therapy and the administration of vinblastine sulfate in combination with alkylating agents.
Caution should be exercised in patients concurrently taking drugs known to inhibit drug metabolism by hepatic cytochrome P450 isoenzymes in the CYP 3A subfamily, or in patients with hepatic dysfunction. Concurrent administration of vinblastine sulfate with an inhibitor of this metabolic pathway may cause an earlier onset and/or an increased severity of side-effects.