The Highs and Lows of Medical Marijuana
Marijuana use is prevalent worldwide yet remains controversial in health care. The general public often regards marijuana as a benign substance, but clear risks are associated with its use. Given the legalization of medical marijuana in more than 20 states, clinicians need to be aware of its negative effects—and its potential therapeutic benefits.
RISKS ASSOCIATED WITH MARIJUANA USE
Acute effects
Most symptoms of marijuana intoxication are attributed to the THC component and occur due to the presence of cannabinoid receptors in the central nervous system (see Table 1).5,10 Additional objective signs of acute or chronic intoxication include conjunctival injection, tachycardia, cannabis odor, yellowing of fingertips (from smoking), cough, and food cravings.10
A more recently identified effect of long-term marijuana use is a paradoxical hyperemesis syndrome, in which individuals experience nausea, vomiting, and abdominal pain. They obtain relief with hot showers or baths.6,8
Since there is a near absence of cannabinoid receptors in the brain stem, marijuana does not stimulate the autonomic nervous system. It is therefore believed that marijuana use cannot be fatal. Corroborating this theory, no deaths have been reported from marijuana overdose.2,11
Withdrawal symptoms
Approximately 10% of regular marijuana users become physically and psychologically dependent on the substance. Once tolerance develops, withdrawal symptoms occur with cessation of use (see Table 2).2,5,10 Symptoms peak within the first week following cessation and may last up to two weeks. Sleep disturbances may occur for more than one month.10
Unlike with other substances of abuse, there are no pharmaceutical agents to treat marijuana withdrawal; rather, treatment is supportive. Marijuana users often resume use following a period of cessation in order to avoid withdrawal.
