Oral Fixation

A new mouth spray form of cannabis might usher in a new era in medicine

By Paul Rogers

While there’s plenty of reasons why California medical marijuana patients worry about access, a cannabis-based spray called Sativex might end up quietly shaking things up. Developed by U.K. company GW Pharmaceuticals, Sativex has proven effective for treating pain from multiple sclerosis spasms and cancer treatment, yet without the psychoactive effects. It’s already been approved for use in the U.K., Canada and Spain and is in late-stage testing for the American market. If or when it becomes available here, dispensaries, caregivers and patients will end up confronting their familiar medicine in a brand-new and unique form.

“Sativex is a cannabis medicine made with whole plant extracts from specifically-bred strains of cannabis sativa. It contains two main cannabinoids or active ingredients: THC (delta-9 tetrahydrocannabinol) and CBD (cannabidiol),” explains Mark Rogerson, a spokesman for GW Pharmaceuticals. “THC has proven analgesic qualities. CBD is a non-psychoactive cannabinoid that has been shown to have properties which may contribute to pain relief. CBD may also reduce unwanted THC-related side effects, such as psychoactive effects.”

Sativex’s mouth-spray delivery system prevents THC from entering the blood stream too rapidly and minimizes unwanted side effects. It’s approved in the U.K. and Spain as add-on treatment for symptom improvement in patients with moderate to severe spasticity due to multiple sclerosis (MS), and in Canada for the relief of neuropathic pain in multiple sclerosis and as an analgesic treatment for cancer patients.

“In GW’s opinion, smoking is not an acceptable means of delivery for a medicine. In addition, current vaporization technologies have not been demonstrated to sufficiently remove all toxins, or ensure a standardized dose,” Rogerson adds. “We believe that patients wish to use a medicine that is legally prescribed, does not require smoking or some form of domestic preparation, is of guaranteed composition and quality, has been developed and approved by regulatory authorities for use in their specific medical condition and is dispensed by pharmacists under the supervision of their doctor.”

Absorbing the Sativex spray through the mouth “allows patients to adjust [titrate] their individual dose without the likelihood of intoxication. In contrast to smoking or vaporizing cannabis, this method of delivery results in a slow rise in THC blood levels, which minimizes any reinforcing effects.”

In the United States, GW and its pharmaceutical development partner, Japan’s Otsuka Pharmaceuticals, are investigating Sativex as an add-on treatment for patients with advanced cancer who are not obtaining adequate pain relief from their current opioid regimen. A Phase II study was completed in November 2009 and Phase III trials began afterward. As a second Phase III study isn’t even due to begin until later this year, we won’t be seeing Sativex stateside any time soon. But, while Rogerson declined to comment on the drug’s role in the medical marijuana debate, he confirmed that it’s probably just the first step in the inevitable march of measurable, dosable medical marijuana in non-plant form.

“There are around 70 cannabinoids, so GW believes that leaves plenty of scope for future development. We have conducted considerable research into CBD and we have commenced a clinical development program of our novel cannabinoid product, delta-9-tetrahydrocannabivarin (THCV). THCV has shown promise in pre-clinical studies as a potential treatment for obesity, diabetes and related metabolic disorders.

“Our partner, Otsuka¸ is funding preclinical research into psychotic illnesses, including anxiety, depression and schizophrenia, as well as central nervous system disorders, including epilepsy. Another program underway with Otsuka is looking at the cannabinoids in the treatment of cancer.”

www.gwpharm.com.

Pill Seekers

Sativex isn’t the first time a pharmaceutical form of cannabis made its presence known. In the early 1980s, the DEA gave its blessings to study one synthetic version of THC, in this case, a pill-based form called Marinol only available via prescription. Research shows that Marinol can help relieve nausea and loss of appetite due to chemotherapy and AIDS. In 1999, the DEA classified Marinol as a Schedule III substance, which basically means the government still considers it a drug—but officially (if not grudgingly) acknowledges its medical usefulness.