Despite all the enthusiasm for marijuana's medical uses, some studies are showing that it is not always as effective as advertised and that there can be significant side effects.
Extracts from the drug are better than most conventional drugs when it comes to treating chronic pain and sickness caused by chemotherapy. But marijuana is not more effective than codeine for controlling acute pain. And, in some cases, the drug triggers paranoia, acute psychosis, cognitive impairment, anxiety and panic attacks in patients.
Many experts believe that medical marijuana, or extracts taken from the drug, are best used for ailments like multiple sclerosis spasms. Doctors are particularly enthusiastic about that discovery, because there are no effective treatments currently available for that problem. The first clinical trials of cannabis-based medicines involving people suffering from MS, spinal cord injuries and other forms of pain are being conducted by a British company called GW Pharmaceuticals. The clinical trials have involved 75 patients over the last 18 months.
Those trials, and other studies, are suggesting that cannabinoids are effective against long-term chronic pain, but that they aren't as effective for acute pain, the kind people experience after surgery.