Cannabis (marijuana) contains more than 60 pharmacologically active cannabinoids; delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the best known. THC is the main psychoactive constituent of cannabis. CBD, unlike THC, does not produce intoxication or euphoria.

Nonopioid drugs can be used in the treatment of many nociceptive and neuropathic pain conditions. Use of opioids for pain will be reviewed in a future issue.

A reader asked why our Cannabis and Cannabinoids article (Med Lett Drugs Ther 2016; 58:97) did not include our usual Dosage/Cost table. We have now posted one in the article as it appears online. You can access it here: www.medicalletter. org/TML-article-1500a.

Download complete U.S. English article

In the US, 25 states and the District of Columbia now permit some medical use of botanical marijuana (Cannabis sativa). It has been used for centuries to treat various ailments, but non-standardization of dosage makes available data difficult to interpret. Cannabis contains >60 pharmacologically active cannabinoids.

Fourteen states in the US - Alaska, California, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Jersey, New Mexico, Oregon, Rhode Island, Vermont and Washington - now permit, or soon will permit, some medical use of marijuana (Cannabis sativa). In some states, licensed facilities dispense botanical cannabis by prescription. In others, limited self-cultivation is permitted for medical use.

Nabilone, an oral synthetic cannabinoid similar to delta-9-tetrahydrocannabinol (THC), the active ingredient in marijuana, has recently been reintroduced to the US market (Cesamet - Valeant) after a 17-year absence. The previous manufacturer discontinued marketing of the drug for commercial reasons. Nabilone is classified as a Schedule II controlled substance.

Ondansetron (on dan' se tron; Zofran - Glaxo), a serotonin (5-hydroxytryptamine) antagonist, was recently marketed in the USA for intravenous use to prevent nausea and vomiting due to cancer chemotherapy. An oral formulation is available in many other countries.

Nabilone (Cesamet - Lilly), a synthetic cannabinoid chemically related to tetrahydrocannabinol (THC), the main active ingredient in marijuana, was recently marketed in the USA for oral treatment of nausea and vomiting associated with cancer chemotherapy. Oral THC itself, known generically as dronabinol (Marinol), is also commercially available as an antiemetic for cancer patients (Medical Letter, 27:97, 1985). Other drugs used for this purpose include metoclopramide (Reglan - Medical Letter, 24:67, 1982), prochlorperazine (Compazine; and others), haloperidol (Haldol; and others), and corticosteroids. Benzodiazepines, such as lorazepam (Ativan; and others), are used to treat anticipatory nausea and vomiting that occurs before chemotherapy begins.