Hur effektiv och säker är sativex jämfört med gabapentin som tillägg till opioider vid cancerrelaterad neuropatisk smärta?

Sammanfattning: Background: Pain is one of the most prominent and disturbing symptoms reported by cancer patients. Appropriate pain relief is obtainable in more than 75 % of the patients with optimized analgesic treatment. Opioids and non-opioids are being utilized in cancer pain treatment and analgesics are used to improve the effectiveness of opioids. Gabapentin is primarily used as an anti-epileptic drug that is also recommended as the first-choice drug in treatment of neuropathic pain. Research is being conducted to evaluate cannabinoids as adjuvans analgesics. Sativex is the extract of cannabis sativa plant and is used to treat and ease moderate to severe symptoms of spasticity caused by multiple sclerosis (MS) in Sweden. Several scientific studies have recently studied sativex with positive results and the drug is currently being used in some countries in treatment of resistant cancer-related neuropathic pain. Purpose: The purpose of this paper was to conduct a scientific study and examine whether sativex is as efficient and secure as gabapentin and thus an option as addendum in cancer-related neuropathic pain when the treatment with only opioids is not sufficient for pain relief. Method: This literature study is based on examination of six clinical scientific studies. The articles are searched in PubMed database, the articles are about examination of effectiveness and security of gabapentin and sativex compared to placebo or other equivalent drugs in cancer patients suffering from neuropathic pain. Results: Two of the studies that compared gabapentin with placebo and one that compared Gabapentin with Amitriptylin (an anti depressive drug) showed that gabapentin was an efficient adjuvans analgesic that led to statistically significant pain relief in patients suffering from cancer. The side effects were mild to moderate in all three studies, and overdose of the study-drug was tolerated well. One of three studies evaluating efficacy and safety of sativex showed that the change in daily average pain score during two weeks of treatment was statistically significant in patients in the sativex-group compared to the group of patients receiving THC-extract and placebo-group. In the second study, sativex was compared within three different dosage groups (low, middle and high) as well as placebo and the result showed that sativex had significant pain relief only in patients receiving low dose of sativex. The third study showed that sativex led to pain relief in patients receiving sativex compared to those receiving placebo however the effect was not statistically significant. Dizziness, nausea and vomiting were the most common side effects in all three studies. The side-effects were mild to moderate and no serious safety issues were observed in the first and third studies. In the second study on the other hand, the patients were encouraged to maintain a stable opioid-dose which resulted in more side-effects. Conclusion: All three studies that examined the effectivness of sativex showed improvement on sleeping quality as well as pain relief, where two of the studies showed statistically significant pain relief in patients suffering from neuropathic cancer-pain. Studies on cannabinoids are quite controversial and there are not many global studies available that have studied its safety and efficacy in the treatment of neuropathic cancer-related pain. It is however a growing and upcoming area that is also expected to grow multiply in turnover which should enable more studies being conducted. These results show that sativex has the potential of being a good alternative in the treatment of neuropathic cancer-related pain. Sativex is also effective in low doses without the need for increases over time, furthermore side effects are mild to moderate and possible overdose is well managed by patients. Gabapentin been used in pain management in neuropathic cancer-pain for a long time with minimal side effects. Sativex, on the other hand, is quite new and there are not many studies performed on the medicine. Furthermore, there are no studies comparing sativex and gabapentin which makes it very difficult to conclude whether it holds the same safety and may act as a good alternative to gabapentin. In future studies, sativex should be compared to medicines used today such as gabapentin in order to prove its ability of being an alternative.