I wonder if the OP could better explain the Marinol. The OP has a "bad back" and takes opiates. Opiates may cause nausea and vomiting. Marinol does seem appropriate therefore but it's really pricey. I presume that Reglan, Zofran et c. were already tried. Why is the insurer refusing to pay for Marinol?
And why is the insurer denying? Oh, that's simple: If they approve synthetic THC for one claimant, that opens the door for every other claimant. And if synthetic THC can be authorized, then the door opens wider for natural THC to be authorized. Even living in a state where Med. Marijuana is legal and legitimized, it is not approved by the Dept. of Labor & Industry (who governs Work Comp here) as a legitimate treatment for workers' compensation claimants. Meaning, even if a Dr. prescribes it, the work comp insurer will not and does not have to pay for it.
Marinol is FDA approved for use w/ nausea and vomiting in CANCER patients. It, to my knowledge, is not approved for use as an adjunct therapy for pain, and pain related symptoms.
Most, if not all states, use either ODG or ACOEM as guidelines for "acceptable" treatments, drugs, modalities, etc. as it relates to workers' compensation. To the best of my knowledge, neither ODG or ACOEM recognizes or recommends the use of THC or synthetic THC as a valid treatment option or alternative for failed back syndrome. FWIW: Pain is NOT a diagnosis, pain is a symptom. Medical records have to reflect objective medical findings to support any diagnosis (especially when talking workers' compensation). Pain is purely subjective. What causes me pain, and my tolerance to pain will not be the same for anyone else, and vice verse. The OP could request a utilization review of the doctors prescribed medication. However, since most states follow ODG or ACOEM as their approved treatment "Bible", Marinol will not be approved.
(http://worklossdatainstitute.verioiponly.com/ : select drug formulary, then scroll down for the list of drugs, and there will either be a yes or no on the right hand side. Marinol and Cannabis/Marijuana are a big fat NO)
Plus, no insurer/Third Party administrator, want to run afoul of the federal government. So, the insurers/TPAs, take a hardline stance on THC/synthetic THC.
Even less controversial drugs that have proven "off label" usage won't be approved, because of the ODG/ACOEM's guidelines. It took forever (it seems) for certain anti-epilepsy drugs to be OK'd for use in patients who had nerve damage and/or chronic muscle spasms due to an injury. Another example: Botox injections have been shown to decrease migraines/headaches that are associated with cervical, head and sometimes shoulder injuries. But, getting that passed the insurance companies has been a battle. Simply because, it is seen as an off label usage. However, in the past few years, it is becoming a little easier.