THC or tetrahydrocannabinol is the active ingredient in Marijuana. Cannabinoids have demonstrated pain relieving effects in certain neuropathic pain conditions. The analgesic effects of these drugs are modest at best. Once ingested, THC binds to receptors in the brain and spinal cord called CB1 and CB2 and modulates the pain perception. These receptors are found within the central nervous system and the periphery. There are chemicals in the body which are called endocannabinoids which are naturally occurring and interact with these receptors as well. When THC compounds are administered to patients, they may increase pain tolerance and decrease pain sensitivity.
Cannabinoids have been used to treat many painful conditions, such as multiple sclerosis, HIV and headaches. Although these medications can be safe and effective, they have many side effects such as dizziness, euphoria and fatigue. The use of these medications carries the risk of misuse, dependency and mental health issues. One idea is to combine THC or cannabinoids with other pain relievers in order to decrease the effective dose of each and use their synergistic effects to treat pain with limited side effects. Using THC in place of narcotics may decrease the tolerance to narcotics that develops over time and diminish the constipation that is associated with chronic narcotic usage. Regulations regarding the use of legal THC agents such as dronabinol ( Marinol) has made prescribing them difficult. That may change in the current regulatory climate. Research is ongoing as to the best usage of these agents and they may soon find a place in our armamentarium for treating chronic painful conditions.