Porter Down, United Kingdom: Long-term administration of Sativex, an oral spray consisting of whole plant cannabis extracts, reduces neuropathic pain compared to placebo, according to clinical trial data released this week by the biotechnology company GW Pharmaceuticals.
Forty-one patients with multiple sclerosis and central neuropathic pain completed the double blind, placebo-controlled “randomized withdrawal” study. Volunteers in the study were administered either Sativex or a placebo daily for four weeks following their long-term use of the cannabis spray.
“In the patients who were randomized to Sativex pain scores remained stable,” the company announced in a press release. “In the patients randomized to placebo, pain and sleep scores deteriorated. … The results of all other symptom-related endpoints showed that Sativex patients maintained or improved their response whilst the symptoms of those who switched from Sativex to placebo worsened in the four weeks following cessation of active treatment.”
Previous open-label extension trials of Sativex have reported that patients required fewer daily doses of the drug and reported lower median pain scores the longer they took it. This trial is the first placebo-controlled trial to confirm the efficacy of Sativex long-term.
Last month, clinical investigators at the University of California at San Diego reported that inhaled cannabis significantly reduces HIV-associated neuropathic pain. The study is the third clinical trial published in the past 18 months demonstrating that inhaling cannabis ameliorates chronic neuropathy.
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