The medical use of marihuana and THC in perspective

The curative properties attributed to marihuana for several thousand pars h ave proved to be disappointing. The ancient oriental claims of marihuana as a pain soother and for the relief of muscle spasms, convulsions, rheumatis m, epilepsy and migraine headaches were introduced into western medicine du ring the 19th century. The reason for the lack of success with marihuana re medies at that time was the same as the present observations encountered wi th THC and all of its novel applications: the variability and inconsistency of its effects associated with unwanted psychological and cardiovascular e ffects. The discovery of THC, the active ingredient of marihuana gave a new impetus for an intensive search for its potential therapeutic applications . THC and its psychoactive derivatives were proposed as analgesic, antidepr essant, hypnotic tranquilizer, as a treatment for withdrawal symptoms, glau coma, spasticity, nausea, vomiting, and to enhance the appetite. Marihuana smoke, in spite of its toxicity to the lung and immune system, was even adv ocated by some as a medically acceptable vehicle for THC. For many of these therapeutic applications, molecular pharmacologists have been able to tail or specific molecules targeted to receptor sites which control acute and in flammatory pain, nausea, vomiting, and glaucoma. These fundamental studies in molecular pharmacology have also provided for an explanation of the ther apeutic inadequacy of THC. This cannabinoid deregulates the physiological s ignaling role of a receptor protein to which it binds and of the membrane b ilipid layer which it permeates. This deregulation of membrane signaling wi ll result in discordant and partial therapeutic effects coupled with unwant ed side effects.