They're a little peeved people have discovered an effective substance they can't get addicted to or overdose on.

There's a famous saying: "Pharmaceutical companies don't create cures; they create customers."

And nowhere is Big Poppa Pharma's distaste for cures more apparent than in their continued effort to put an end to medical marijuana.

A huge body of research shows that prescription painkiller abuse and overdose are far lower in states with medical marijuana laws. In fact, it's been estimated that medical marijuana could help curb drug overdose deaths by 25 percent. his has been known to infuriate pharmaceutical companies, as people who've wised up to weed's medicinal benefits stop spending money on harmful drugs and more on helpful herbs.

However, a new study has validated that assumption by providing evidence of a missing link in the causal chain between medical marijuana and falling overdose deaths.

Dad-and-daughter researchers Ashley and David Branson at the University of Georgia found that in the 17 states with medical weed laws in place, prescriptions for painkillers and other drugs decreased sharply compared with states that did not have any legal weed at all.  The drops were actually quite severe—in states with medical pot, the average doctor prescribed 265 fewer doses of antidepressants each year, 486 fewer doses of seizure medication, 541 fewer anti-nausea doses and 562 fewer doses of anti-anxiety meds.

Perhaps most strikingly though, the average physician in a medical marijuana state prescribed 1,826 fewer doses of painkillers in a year. This is a huge deal, as prescription painkiller overdose is the leading cause of injury-related death in the United States. More people die from Big Pharma's bountiful offerings than in car accidents in this here country. Meanwhile, marijuana, however, has killed exactly zero people ever, nor does it plan to.

Understandably, the plummeting sales of prescriptions in medical marijuana states is likely to cause some hand-wringing among pharmaceutical execs—men and women who care more about their company's bottom line than the rising death toll their products are responsible for. This is why they've long been at the forefront of opposition to marijuana reform. Currently, pharmaceutical companies are some of the largest funders of research by anti-pot academics, funneling millions of dollars into the pockets of groups that fight legalization. They've even gone so far as to lobby federal agencies like the DEA to prevent the expansion of marijuana laws. Clearly, they're more than a little worried that this simple leafy green could threaten the flex of their power over the market.

Even more concerning for drug companies though, is the Bradfords' finding that medical marijuana decreases Medicare spending. By their calculations, about $165 million was saved in the 17 medical marijuana states in 2013 alone. Expanding those savings in a hypothetical country-wide situation, the estimated annual Medicare prescription savings would be nearly half a billion dollars if all 50 states were unite under the hazy umbrella of medical weed.

For drug companies, that's like telling them they're getting a new Ford Escape instead of a new Mercedes-Benz G-Class. Boo hoo!

So, what's a poor Big Pharma to do?

If you can't beat 'em—join 'em.

That's the only option for drug companies if and when the DEA decides to reschedule marijuana, something they're currently in the process of discussing (a decision is expected later this year).

If pot gets downgraded from a Schedule I substance to a Schedule II or lower, pharmaceutical companies will have the ability to manufacture it into market-ready prescriptions and revel in the profit. If they do that, the FDA will have direct control over how much THC, CBD and other cannabinoids may be present in each dose.

This could be good because it would lead to more standardized dosing and labeling, but the downside of that is that it's unlikely the FDA would approve the sorts of high doses people use on themselves to treat their own medical conditions. Since pot has such wildly different effects on people, and everyone responds to different potencies uniquely, having the option to access highly potent weed is important for people with higher tolerances or more advanced medical conditions. Not that pharmaceutical companies really care about medical conditions though …

Given that Big Pharma's baseline drive is profit, not therapy, it's a little scary to imagine what them sinking their opioid-encrusted talons into the medical marijuana market would look like. We just hope that by the time they do, more states will have implemented recreational programs that allow people to skirt Pharma's scaly grasp.