Medical Cannabis: The Patient's and the Doctor's Dilemmas*
by Lester Grinspoon, M.D.

*Editorial: Addiction Research, 2000, Vol. 8, No. 1, pp. 1-4

There is every reason to believe that the medical use of cannabis will continue to become more common in the United States and elsewhere. News of the many symptoms and syndromes for which it is an effective treatment is constantly spread by word-of-mouth, the Internet, and books and articles in lay journals. In increasing numbers, people are discovering that it is a remarkably non-toxic, inexpensive, and versatile medicine. Legislation enabling patients to use cannabis may soon be enacted in some European countries, New Zealand, Australia, and Canada.

So far, unfortunately, there is little to suggest that the United States will follow suit in the foreseeable future. A half dozen states have passed initiatives which would permit patients to use cannabis with a doctor's written recommendation, but the conditions are usually so narrowly defined that only a fraction of those who could benefit would be served. Furthermore, the federal government has resisted all attempts by the states to make provisions for legal distribution of medical cannabis. Private groups have organized cannabis buyers clubs where patients who have a physician-certified need can buy small amounts, but most of these clubs have now been closed by state and local authorities. In California, the first state to pass a medical cannabis initiative, the federal government has been so successful at intimidating physicians that few patients are legally using cannabis.

Meanwhile, the number of case reports on medical marijuana is mounting, and a mass of clinical experience is accumulating. The results of the report on medical cannabis by the Institute of Medicine (of the National Academy of Science) are being disseminated, and controlled studies will soon be undertaken and published. As a result, the US government will have to modify its policy of insistent denial that cannabis has medical uses. To solve this problem, it will predictably take the position that only Marinol (dronabinol, a synthetic tetrahydrocannabinol) and other yet-to-be-developed cannabinoids or synthetic cannabinoid analogs should be available as medicines. The government will allow tightly controlled prescription of these derivatives while maintaining a harsh prohibition against the use of whole smoked cannabis for any purpose. But most patients find smoked cannabis more useful than Marinol, and many will find the new analogs to be inferior as well. Furthermore, Marinol is more expensive than marijuana, even at the inflated prices imposed by prohibition, and new cannabis-derived medicines will probably be still more costly. It is easy to predict that many patients will continue to buy marijuana on the street or grow it themselves.

Most patients who use cannabis do so because they compare it with the medicines their physicians have prescribed and find that it is more effective, or has fewer and less toxic side effects, or both. This often creates a dilemma for patients: should they share this discovery with their physician? They correctly believe that for the best medical results they need a physician's agreement and support, but if they tell the doctor, they are likely to encounter disapproval or at best indifference. The attitudes of most physicians toward medical marijuana have been shaped largely by politically imposed ignorance. After the passage of the 1937 Marijuana Tax Act and the subsequent removal of cannabis from the pharmacopeia, physicians allowed themselves to become both victims and agents of a government-sponsored disinformation campaign against marijuana.
Now some of them have begun to learn about its therapeutic uses, not from the usual sources -- medical school pharmacology courses, medical journals, the promotional activities and materials of drug companies -- but from their patients. These physicians are persuaded that marijuana is often more effective and less toxic than some of the medicines they are allowed to prescribe. But they find themselves in a difficult position. They feel constrained by the law, the attitude of their peers, and the risk of running afoul of a medical licensing board. Those who decide to recommend cannabis will often add that they should not be quoted. And even these physicians are usually ill equipped to provide the advice, support, and monitoring that are so important for patients taking any drug, especially an unfamiliar one.

The prescription of cannabis, whether through smoking or ingestion, is not as simple as prescribing a conventional medicine. The psychoactive effects should be carefully explained so that patients will not be taken by surprise or made uncomfortable by the slightly altered state of consciousness. They must know how to recognize these effects so they can avoid taking more of the drug than necessary. It is often advisable for a cannabis-patient to smoke for the first time or two in the presence of an experienced user and wait for several minutes between puffs.

An uncommon but significant side effect of marijuana is a transient state of anxiety, sometimes accompanied by paranoid thoughts and occasionally mounting to a short-lived incapacitating panic. The condition is self-limiting, and simple reassurance is the best treatment. Anxiety and paranoid thoughts are most likely to develop in an inexperienced user who is taking the drug in an unpleasant and unfamiliar setting. These reactions become less common as general and individual familiarity with the drug grows. The danger is greatest when the drug is illegal, its potency is unknown or uncertain, and the patient is unprepared, alone, and without guidance. Anxiety reactions would be easy to avoid if a knowledgeable physician were allowed to help prepare the patient, determine the dose and route of administration, and provide support.

Another medical problem is the absorption of cannabis by mouth. Since 1985 physicians in the United States have been allowed to prescribe Marinol orally in capsule form. It is officially available for the treatment of two of the many symptoms and syndromes for which cannabis is useful: relief of nausea and vomiting in cancer chemotherapy and appetite enhancement in patients suffering from the weight reduction syndrome of AIDS. However, smoked cannabis may be preferable for several reasons. A patient who is severely nauseated and constantly vomiting may find it impossible to keep a capsule down. Furthermore, because the effects of smoked cannabis are perceived almost immediately, patients can take only what they need for a therapeutic effect. Oral THC, by contrast, is subject to the vagaries of bioavailability. Two patients who take the same amount may absorb different proportions of the dose, and any given patient's absorption may vary from day-to-day, depending on the time of day, the state of the patient's intestinal tract, and other factors. Patients who swallow a Marinol pill (or whole cannabis in the form of food or drink) may discover after an hour that they have taken too much for comfort or, more often, not enough to relieve their symptoms. Nineteenth-century physicians knew that cannabis was remarkably safe, but they also knew about the imprecision of dosage and variability of oral absorption. Therefore, they preferred to err on the side of giving more rather than less. When cannabis is taken orally or as a suppository (usually in the form of cannabis-butter cooled in the freezer), the main concern is undermedication.

These are only a few of the issues that conscientious physicians should discuss with patients to whom they recommend this medicine. But as I have pointed out, few contemporary physicians know enough to provide the necessary information, and many are reluctant or afraid to discuss an illegal activity. Until physicians become better informed about and more comfortable with this medicine, most patients who use it -- and many certainly will -- must continue to take the legal and other risks of acting almost entirely on their own.