Marijuana as Medicine

MARIJUANA’S therapeutic uses are well documented in the modern scientific literature.  Using either smoked marijuana or oral preparations of delta-9-THC (marijuana’s main active ingredient), researchers have conducted controlled studies.  These studies demonstrate marijuana’s usefulness in reducing nausea and vomiting, stimulating appetite, promoting weight gain, and diminishing interocular pressure from glaucoma.  There is also evidence that smoked marijuana and/or THC reduce muscle spasticity from spinal cored injuries and multiple sclerosis, and diminish tremors in multiple sclerosis patients.  Other therapeutic uses for marijuana have not been widely studied.

However, patients and physicians have reported that smoked marijuana provides relief from  migraine headaches, depression, seizures, insomnia, and chronic pain.   Delta-9-THC is probably responsible for most of marijuana’s therapeutic effects, but one of marijuana’s other cannabinoid constituents–cannabidiol–appears to be useful as an anticonvulsant. Other cannabinoids may yet prove to have medicinal value.

In the United States, using marijuana for medical purposes is illegal because federal law includes marijuana in Schedule I, a category for drugs deemed unsafe, highly subject to abuse, and possessing no medicinal value.

Nonetheless, since the 1970s, thirty-five state legislatures have passed laws supporting marijuana’s use as a medicine.  In 1996, voters in California and Arizona approved ballot initiatives to remove state criminal penalties for possessing marijuana for medicinal use.  However, federal law prevents states from making marijuana supplies legally available.  Eight people receive marijuana through a federal “compassionate use” program which stopped admitting new patients in 1992 after the number of applications, mostly from AIDS patients, increased dramatically.  Thousands of Americans use marijuana as a medicine illegally, putting themselves at risk of arrest and prosecution.  Undoubtedly, others who might benefit from marijuana are deterred by its illegality.

Since 1986. synthetic THC (Marinol) has been available as a Schedule II drug, which allows physicians to prescribe it under highly regulated conditions.  Marinol is labeled officially as an anti-nauseate and an appetite stimulant, but doctors can and do prescribe it for other conditions, such as depression and muscle spasticity.  This oral preparation of THC, dissolved in sesame oil, works for some patients.  However, many patients find that smoked marijuana is more effective.  For people suffering from nausea and committing, who are unable to swallow and hold down a pill, smoking marijuana is often the only reliable way to deliver THC.

For nauseated patients, smoking marijuana has the additional advantage of delivering THC quickly, providing relief in a few minutes, compared to an hour or more when THC is swallowed.  Smoking marijuana not only delivers THC to the bloodstream more quickly than swallowing Marinol, but smoking delivers most of the THC inhaled.   When Marinol is swallowed, it must move from the stomach to the small intestine before being absorbed into the bloodstream.  After absorption, orally consumed THC passes immediately through the liver, where a significant proportion is bio transformed into other chemicals.

Due to metabolism by the liver, 90 percent or more of swallowed THC never reaches sites of activity in the body.  Two hours after swallowing ten to fifteen milligrams of Marinol, 84 of subjects in a recent study had not measurable THC in their blood.  After six hours, 57 percent still had none.  By contrast, two to five milligrams of THC consumed through smoking reliably produces blood concentrations above the effective level within a few minutes.

When THC is swallowed, the effects vary considerably, both from one person to another and in the same person form one episode of use to another.  And because the onset of effect is an hour or more, patients using Marinol have difficulty achieving just the effective dose.  When THC is swallowed, the effects last longer–up to six hours, compared to one or two hours when marijuana is smoked.  In other words, smoking marijuana is a more fexible route of administration than swallowing.  Smoking allows patients to adjust their dose to coincide with the rise and fall of symptoms.   For people suffering from nausea and vomiting from AIDS or cancer chemotherapy, smoked marijuana provides rapid relief with lower overall doses of THC. 

Another problem with swallowed THC is that the psychoactive side effects may be more intense than those that occur from smoking.  When the liver bio transforms THC, one of the metabolites it produces a 11-hydroxy-THC, a compound of equal or greater psycho activity.  Some 11-hydroxy-THC is produced when marijuana is smoked, but its concentration seldom reaches psychoactive levels.  With oral ingestion, patients experience psychoactive effects from THC *and* 11-hydroxy-THC, increasing the likelihood of adverse psychological reactions (see chapter 10).  There is also some evidence that one of marijuana’s other cannabinoids–cannabidiol–modulates the psychoactive properties of marijuana.  In a study of elderly patients, the large dose of oral THC needed to reduce nausea and vomiting produced severe psychoactive effects, reducing its utility as a medicine.

Given these problems, it is not surprising that physicians prescribe Marinol rarely.  In one study, researchers asked oncologists (cancer specialists) to rank the effectiveness of available medications for the treatment nausea and vomiting from cancer chemotherapy.  They ranked THC (in natural or synthetic form) as ninth, accounting for only 2 percent of anti-emetic prescriptions. In another study, 49 percent of oncologists said they had prescribed Marinol, but only 5 percent had prescribed it more than ten times.  A 1990 survey asked oncologists to compare the effectiveness of Marinol and smoked marijuana.

Only 28 percent felt familiar enough with both drugs to answer the question.  Of these, only 13 percent though Marinol was better; 43 percent believed the two forms of THC were equally effective, and 44 parents believed smoked marijuana was better.  Four hundred and thirty0two oncologists (44 percent of those who returned the questionnaire) said they had recommended smoked marijuana to at least one of their cancer patients.

In a 1994 survey, 12 percent of oncologists said they might prescribe it if it were legal. Smoking is a highly unusual way to administer a drug.  Many drugs could be smoked, but there is no good reason to-do so because oral preparations produce adequate blood concentrations.  With THC this is not the case.

Inhaling is a better route of administration that swallowing.  Inhaling is about equal in efficiency to intravenous injection, and considerably more practical. Other than its illegality, the primary drawback of smoking marijuana is that it deposits irritants in the lungs.  With prolonged high doe use, this could cause pulmonary problems (see chapter 15).  However, with short-term use, there is little risk of lung damage.  For terminally ill patients, the potential harm of smoking is of little consequence.  Other THC delivery systems–for example, suppositories and aerosol sprays–have not been proven effective, but should be studied further.  Given currently available options, smoking marijuana is the most efficient and effective way to deliver THC.  It is also potentially the cheapest.  A patient taking twenty milligrams of Marinol per day would spend $600 or more per month for medication.  With the “black market tax” on marijuana removed, plant preparations could be delivered to patients at a fraction of the cost of Marinol.

In the 1970s, the federal government funded research into marijuana’s therapeutic uses and provided marijuana supplies to qualified researchers. It also established the “compassionate use” program, through which patients, on a case-by-case basis, could obtain marijuana from the government’s marijuana farm in Mississippi.  In its 1976 *Marijuana and Health* reports to Congress, the National Institute on Drug Abuse (NIDA) recommended further exploration of marijuana’s medicinal uses.  NIDA’s next two reports, in 1977 and 1980, reiterated this position.

Ronald Reagan’s election as president in 1980 brought a renewed war on marijuana and an end to the federal government’s support for medical marijuana.  NIDA’s 1982  *Marijuana and Health*  report to Congress reversed its earlier position.  It warned that “the negative health effects of marijuana” diminished its therapeutic potential, and suggested that“synthetic analogs of marijuana derivatives” should be pursued instead.

Opposition to medical marijuana continues under the Bush administration.  In 1989 the head of the Drug Enforcement Administration (DEA), John Lawn, denied a petition by the National Organization for the Reform of Marijuana Laws (NORML) to reclassify marijuana as a Schedule II drug.  This change would have allowed physicians to prescribe marijuana under the strict regulations that now apply to amphetamine, morphine, and cocaine.  Lawn denied the petition despite a recommendation for rescheduling by the DEA’s own administrative law judge, Francis L. Young.  After reviewing the evidence, Judge Young concluded not only that marijuana’s medical utility had been adequately demonstrated, but that marijuana had been shown to be “one of the safest therapeutically active substances known to man.”  The U.S. Court of Appeals upheld the legal authority of the DEA administrator to ignore Judge Young’s decision.  Today, marijuana remains in Schedule I, a category for drugs deemed unsafe, highly subject to abuse, and possessing no medicinal value.

In 1992, the Bush administration shut down the compassionate use program and the Clinton administration, after some wavering decided against reinstating it.  The DEA continues to oppose any legal change that would make marijuana available as a medicine and even opposes further research on the topic. There have been no government-funded studies of marijuana’s medical utility in more than a decade.  When California AIDS researcher Dr. Donal Abrams proposed to compare the effectiveness of Marinol to smoke marijuana in the treatment of AIDS-related wasting syndrome, NIDA denied him access to marijuana supplies–despite the fact that his study had received prior approval from the Food and Drug Administration (FDA).  In 1996, the Clinton administration opposed voter initiatives in California and Arizona to legalize marijuana for medical use.  After both initiatives passed, federal

officials threatened to criminally prosecute physicians or revoke their licenses to prescribe controlled substances–simply for recommending smoked marijuana to their patients.

A number of anti-drug organizations argued against legalizing the medical use of marijuana, claiming that any change in the law would send the “wrong message” to teenagers about marijuana’s dangers.  Most formal associations of physicians have not taken an official position on medical marijuana. However, the federal government’s strict prohibitionist position is opposed by the American Public Health Association, the Federation of American Scientists, the Physicians Association for AIDS Care, the Lymphoma Foundation of America, and former U.S. Surgeon General Joycelyn Elders, as well as national associations of prosecutors and criminal defense attorneys.  The  *New England Journal of Medicine * has taken a stand in support of allowing marijuana’s use as medicine, and the  *Journal of the American Medical Association * published an invited editorial with the same message.

The editorial boards of numerous newspapers have urged the Clinton Administration to loosed current restriction–a view that recent opinion polls show is supported by a majority of Americans. In defiance of existing law, people across the country use marijuana for medical purposes.  Some do so with the knowledge and approval of their physicians.  Because the practice is illegal, more patients use marijuana medicinally without medical supervision.  Marijuana’s illegality means tha patients cannot be sure of obtaining standardized products that are free of funal spores–a critical problem for AIDS patients who have suppressed immune systems (see chapter 14).  In some cities, “cannabis buyer’s clubs” have formed to supply uncontaminated products to patients.  However, in most parts of the country patients must rely on criminal markets that deliver marijuana of unknown potency and purity.  Reclassifying marijuana as a Schedule II drug and creating a legal system for its distribution would guarantee that all patients have access to pure, standardized marijuana.

For new drug approval, the FDA requires “substantial evidence”  of efficacy, based on “adequate and well-controlled clinical investigations”, plus evidence of the drug’s limited toxicity when used in therapeutic doses. Smoked marijuana meets this standard.  Based on a review of twenty-five years of research, pharmacologist Roger Pert we concluded that “there is no evidence to suggest that psychotropic cannabinoids (or cannabis) are particularly unsafe or that their adverse effects are any more severe or unacceptable than those of many drugs now used clinically. In an important sense, the FDA’s prior approval of oral THC  *is*  evidence of marijuana’s effectiveness in treating nausea, vomiting, and AIDS-related wasting.  The few studies that have directly compared the two forms of THC delivery show smoke marijuana to be more effective than oral administration.  In any case, the question is not whether marijuana is   *better*  than existing medication.  For many medical conditions, there are numerous medications available, some which work better in some patients and some which work better in others.  Having the maximum number of effective medications available allows physicians to deliver the best possible medical care to individual patients.

Politics, not medical science, has stood in the way of marijuana’s approval as a legal medication.  In a 1982 letter to the  *Journal of the American Medical Association,* Congressman Newt Gingrich wrote that the “outdated federal prohibition” of medical marijuana was “corrupting the intent of state laws and depriving thousands of glaucoma and cancer patients of the medical care promised them by their state legislatures.”  According to Gingrich, “the hysteria . . . over marijuana’s social abuse” and “bureaucratic interference” by the federal government had prevented “a factual [and] balanced assessment of marijuana’s use as a mendicant.” Fifteen years later, that observation is still accurate.


MARIJUANA IS HIGHLY ADDICTIVE.  Long-term marijuana users experience physical dependence and withdrawal, and often need professional drug treatment to break their marijuana habits.

“There is a demand for marijuana-specific treatment that is currently unmet.  Marijuana dependence is a challenge that does not pale in comparison to other dependencies, as many people think.”

 “Marijuana can put a serious chokehold on long-term users who try to quit.” 

“Studies show that after abruptly stopping marijuana use, the long-term heavy pot user may develop signs and symptoms of withdrawal.”

“In 1993, over 100,000 people entering drug treatment programs reported marijuana as their primary drug of abuse, showing they need help to stop.”



A small minority of Americans–less than 1 percent–smoke marijuana on a daily or near daily basis.  An even small minority develop dependence on marijuana.

Some people who smoke marijuana heavily and frequently stop without difficulty.

Others seek help from drug treatment professionals.

Marijuana does not cause physical dependence.

If people experience withdrawal symptoms at all, they are remarkably mild.