THERAPY – CANNABINOIDS
The cannabinoids are derived from the resin of the plant Cannabis sativa. The only known active constituent is 9-tetrahydrocannabinol (δ9-THC). Other cannabinoids are an oral synthetic nitrogen analogue of THC and intramuscular levonantradol. There are claims for their use in nausea and vomiting, appetite stimulation in HIV-infected patients, movement disorders and glaucoma. There have also been claims that cannabinoids are useful in the treatment of migraine and painful spasticity in multiple sclerosis and spinal cord injury. There is some evidence that they are analgesic in humans. A systematic review of nine randomized controlled trials has concluded that there need to be further trials into their use in spasticity and neuropathic pain but they have no place in the management of postoperative pain. A double-blind comparison with placebo in a patient with prior history of cannabinoid use has demonstrated an opioid-sparing effect in chronic pain.