der any circumstance, medicate themselves with marijuana, an illegal drug.

  • The medical information in this book is not intended to substitute for the advice of a physician or other health care professional.

Now that you know where this book came from and where it's going, we offer a few guideposts to aid your journey through it. Because the following key concepts underlie our discussion of medical marijuana, familiarizing yourself with them will help you make the most of your reading.

Marijuana contains a complex mixture of chemicals. Marijuana leaves or flower tops can be smoked, eaten, or drunk as a tea (see Figure 1.1). People who use marijuana in these ways expose themselves to the complex mixture of chemical compounds present in the plant. One of these chemicals, tetrahydrocannabinol (THC), is the main cause of the marijuana “high.” Thus, the effects of marijuana on the body include those of THC, but not all of marijuana's effects are necessarily due to THC alone.

According to federal law, marijuana belongs to a category of substances that have a high potential for abuse and no accepted medical use. Other drugs in this category include LSD (lysergic acid diethylamide) and heroin. By contrast, doctors can legally prescribe THC, in the form of the medicine Marinol (a brand name for a specific formulation of the generic drug dronabinol), under highly regulated conditions. Dronabinol, the “synthetic” THC in Marinol, is identical in every way to the “natural” THC in marijuana.

The FDA has approved Marinol for the treatment of nausea and vomiting associated with cancer chemotherapy and also to counteract weight loss in AIDS patients. Currently classified with controlled substances such as anabolic steroids, Marinol was moved from a more restrictive category, which included cocaine and morphine, in July 1999.

Some of the medical studies discussed in later chapters deal with the effects of marijuana, while others focus on specific chemicals present in the marijuana plant. This distinction should be kept in mind when considering the results of these studies. The psychoactive chemicals in marijuana are members of a family of mol-

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