For long period of time, there was a worldwide debate about the legitimization of cannabis for the therapeutic use for different conditions. Cannabis is originally used recreationally as it produces significant euphoric effects. However, the adverse effects of cannabis and cannabinoids, which affect the cognitive and psychomotor functions, limited their medicinal application. Nonetheless, with the development of synthetic cannabinoid compounds with an improved safety profile, clinicians have paid attention to such chemical compounds, particularly for the treatment of pain, considering its comparison to other pain-relieving drugs. The latter may be classified as acute (rapid onset and lasts for short time), cancer-related, and chronic non-malignant pain (the patient suffers from pain over long periods). This article demonstrated the available literature concerned with studying the efficacy of cannabinoid treatment for pain, focusing on their safety and tolerability patterns.
Here is the full scientific article if you wish to download it.
Efficacy of cannabinoids in the treatment of cancer and non-malignant pain
Given that the pain-reducing actions of cannabinoids in the treatment of acute postoperative pain is equally-effective as codeine, producing notable psychoactive adverse effects, it is important to investigate the efficacy of cannabinoids for relieving pain that lasts for long periods. For cancer-related pain, orally-given tetrahydrocannabinol (THC, the naturally occurring cannabinoid) had only a superior analgesic effect when compared to placebo. Typical effects were also observed when other synthetic cannabinoids, such as benzopyranoperidine, have been investigated in patients with advanced cancer. On the other hand, the efficacy of cannabinoids was as effective as codeine in a consistent manner across all studies. Regarding chronic non-malignant pain, THC showed no better outcomes in regards to pain relief when compared to morphine in the patients suffering from Mediterranean fever, while the pain-alleviating dose was much higher when receiving THC. In patients with neuropathic pain due to spinal cord pathology, oral THC was superior to codeine to relieve the associated spasticity.
Safety of cannabinoids as analgesic medications
Although the potency of cannabinoids has been remarkably augmented with increasing its dose, the side effects, which are mainly psychotropic, were commonly reported. Actually, this is of a great relevance since enhancing the analgesic effect may be frequently required in patients with cancer pain. Depression of the central nervous system and some mild cardiovascular adverse effects were reported following the use of oral THC at daily doses ranging between 10 and 20 mg. Additionally, sedation and/or drowsiness were the most apparent symptoms after receiving intramuscular levonantradol, a synthetic cannabinoid. In general, the need to increase the dose of cannabinoid compounds for the treatment of pain may render the patient prone to develop adverse effects.
The present study showed that cannabinoids, mostly THC compounds, were as effective as codeine for the treatment of cancer-related and non-malignant pain. Cannabinoids were associated with some adverse effects that might be attributable to their effects on the brain and behavior. It is therefore recommended to conduct future studies using synthetic or natural alternatives, which may have more potent therapeutic effects with a safer profile.