IACM-Bulletin of April 3, 2005

Holland — Health minister considers stopping the sale of medicinal cannabis in pharmacies

Health Minister Han Hoogervorst is considering abandoning the legal sale of medicinal cannabis in pharmacies and closing the Office of Medicinal Cannabis. In response to questions from the Tweede Kamer (House of Representatives of the Dutch parliament) he said on 17 March that he intends to decide on the future of the program after summer.

Questions were related to the status of the program, which started to sell cannabis in pharmacies in September 2003 and lost 400,000 Euros in 2004. Hoogervorst said that in times of budget cutbacks, such a project was destined to be stopped. He also noted that doctors were not very positive about prescribing cannabis to patients and that patients prefer to buy it from coffee-shops.

Hoogervorst also claimed that the medicinal properties of cannabis have never been proven and that the use of cannabis may cause side-effects such as psychoses. But the Office of Medicinal Cannabis asserted that patients do benefit from cannabis and psychoses occur only rarely. The PvdA (Partij van de Arbeid, Labour Party) called on the minister to put more energy into the success of the program.

(Sources: expatica.com of 18 March 2005, De Volkskrant of 18 March 2005, NRC Handelsblad of 18 March 2005)

Science — THC and cannabis increase food intake in HIV positives with weight loss

Researchers at the Columbia University in New York investigated the effects of 10, 20, and 30 mg of oral THC and cannabis cigarettes of different potencies (1.8, 2.8, and 3.9 percent THC) on food intake in two groups of HIV positive cannabis smokers in eight 7-hour sessions. One group consisted of 15 subjects with significant loss of muscle mass and the other of 15 subjects without loss of muscle mass.

The three different cannabis cigarettes and the two lower THC doses (10 and 20 mg) were well tolerated with few physical symptoms and significant increases in ratings of "good drug effect", while the highest dose of THC (30 mg) caused significant side effects in some participants. Both THC and cannabis increased caloric intake in the group with weight loss but not in the control group. The effects on cognitive performance were minor.

Authors conclude that "for experienced marijuana smokers with clinically significant muscle mass loss, both dronabinol (at acute doses at least four to eight times the current recommendation) and marijuana produce substantial and comparable increases in food intake without producing adverse effects."

(Source: Haney M, et al. Dronabinol and marijuana in HIV+ marijuana smokers: acute effects on caloric intake and mood. Psychopharmacology 2005 Mar 19; [Electronic publication ahead of print])

Science — Oral THC claimed to induce psychosis

A study by researchers of the University of Lausanne, Switzerland, on oral THC in eight healthy volunteers, of whom two developed psychotic reactions for some hours after ingestion, received some media attention. The press agency Reuters noted "Oral Cannabis Induces Psychosis at Low Levels". However, subjects did not receive low doses of THC and they did not develop a psychosis but psychotic reactions, such as anxiety and delusion, well known side effects of cannabis ingestion.

Participants in the study were occasional users of cannabis and received either 20 mg of oral THC (Marinol) or an oral cannabis preparation containing either 15.8 or 45.7 mg THC on average. The study intended to investigate psychomotor impairment and driving capability after cannabis use. The two cases who developed psychotic symptoms were 22-year-old men who received 20 mg of THC or a cannabis preparation containing 16.5 mg THC. In both cases psychic side effects disappeared within several hours after ingestion.

Researchers expressed their surprise about the anxiety causing effects of THC which, however, are well known. Usually clinical studies start with single doses of 2.5 or 5 mg THC, rarely with 10 mg THC to find out the appropriate and tolerated dose and to avoid severe side effects. The tolerated doses vary considerably in different subjects. Only in regular users higher doses should be applied as starting dose. In recent clinical studies tolerated doses varied between 5 and about 100 mg THC daily.

(Sources: Reuters of 1 April 2005, BBC News of 1 April 2005, Favrat B, et al. Two cases of "cannabis acute psychosis" following the administration of oral cannabis. BMC Psychiatry 2005;5:17)

News in brief

Two Chilean lawmakers plan to introduce a bill to legalize medical cannabis after recent high profile arrests of a wealthy grandmother and a retired economist for growing the drug for medical purposes sparked national debate. Laura Soto of the Party for Democracy which is part of the ruling centre-left Concertacion coalition and her party colleague Antonio Leal said they would introduce their bill in the coming days. The proposal would make cannabis available through pharmacies and eliminate penalties for people who grow cannabis for personal medicinal use. One of the arrested subjects is Maria Luisa Velasco, the ex-wife of a former senator. (Source: Reuters of 28 March 2005)

Science — Synergistic effects in pain

Australian researchers investigated possible synergistic and additive effects of a cannabinoid (CP55,940), morphine and dexmedetomidine in acute pain models in mice. Synergistic (more than additive) interactions were observed between the cannabinoid and dexmedetomidine in the hot plate test, and between the cannabinoid and morphine in the hot plate test and the tail flick test. (Source: Tham SM, et al. Br J Pharmacol 2005;144(6):875-84.)