I am looking for information relating to the pharmacological interaction between Chemotherapy agent Pazopinib (Votrient) and Cannabinoids. Clinical studies seem to be few.
We know that Medinol (Drobinol/synthetic THC) is prescribed and used alongside Pazopinib in the states (pharmacological interaction studies must have been done here). Sativex (THC 50%, CBD 50%) is the only pharmaceutical cannabinoid available in the UK, are there any known studies as to the interaction of Pazopinib and Sativex?
We are aware that cannabinoids induce metabolizing enzymes in the liver, that Pazopinib is a cyp450 and related enzyme inhibitor. Therefore cannabinoids interact with Pazopinib, increasing the uptake of the chemotherapy agent in the body and may lead to increased toxicity levels and elevation of related side effects.
Specifically the following types of medicine can interact with Pazopinib, BCRP inhibitors, cytochrome p450 inhibitors and p-glycoprotein inhibitors - all of which specific compounds of cannabis can be.
Depending on the administration of the cannabinoid treatment, we can bypass the first pass metabolism effect of the liver by delivering the cannabinoids via sub-lingual and transdermal applications (both through the skin and as a suppository). This method of administration may help reduce or remove the metabolizing interaction between the two drugs but can it cause significant interactions elsewhere? We can also reduce the dose of Pazopinib counteracting the increased uptake of the drug when used in combination with cannabinoids (CYP450 inducers are known to increase the levels of bio available Pazopinib by 60%).
If anyone has any information or can direct me to clinical studies, reports or an integrative oncologist who may know the answer to our question we would be very thankful.