Opioid companies should view medical marijuana as a direct competitor of the products they distribute. A major argument for the legalization of medical marijuana is the possibility of pain relief. Opioids are prescribed, primarily, to relieve pain. Therefor it would only make since for opioid companies to oppose medical marijuana.
While opioids are specifically for pain, marijuana is for pain and a number of other things such glaucoma. It is sheer greed on the part of the opioid manufacturers to fight every time a state tries to pass a medical marijuana or other pro-marijuana law. They need to spread the wealth.
Opioid companies can add medical marijuana to thier line of products. It is similar to opiates, can be sold the same way, and can be used either instead of or along side opiates. It would be good for their business to support medical marijuana and they can benefit from some of the new laws.
If you want examples of this, look no further than in Arizona where big Pharam just donated $500k to fight the medical cannabis vote. They say the did it in the name of public safetly, but another diligent reporter uncovered the fact that in one of their recent SEC filings they stated how the legalization of cannabis would certainly harm their new sythetic THC drug they are developing. Oh, and that company currently makes Fentenal spray. Article like this one need to be more in the mainstream media.