[Editor's note: The New England Journal of Medicine recently polled physicians across specialties about their views on medicinal use of marijuana.
The case vignette that was presented and the comments -- pros and con -- that it elicited can be viewed here.]
CLINICAL DECISIONS
Medicinal Use of Marijuana
N Engl J Med 2013; 368:866-868February 28, 2013DOI: 10.1056/NEJMclde1300970
Comments and Poll open through March 6, 2013
Share:
CASE VIGNETTE
Marilyn is a 68-year-old woman with breast cancer metastatic to the lungs and the thoracic and lumbar spine. She is currently undergoing chemotherapy with doxorubicin. She reports having very low energy, minimal appetite, and substantial pain in her thoracic and lumbar spine. For relief of nausea, she has taken ondansetron and prochlorperazine, with minimal success. She has been taking 1000 mg of acetaminophen every 8 hours for the pain. Sometimes at night she takes 5 mg or 10 mg of oxycodone to help provide pain relief. During a visit with her primary care physician she asks about the possibility of using marijuana to help alleviate the nausea, pain, and fatigue. She lives in a state that allows marijuana for personal medicinal use, and she says her family could grow the plants. As her physician, what advice would you offer with regard to the use of marijuana to alleviate her current symptoms? Do you believe that the overall medicinal benefits of marijuana outweigh the risks and potential harms?
TREATMENT OPTIONS
Which one of the following approaches do you find appropriate for this patient? Base your choice on the published literature, your clinical experience, recent guidelines, and other sources of information.
Option 1: Recommend the Medicinal Use of Marijuana
Option 2: Recommend against the Medicinal Use of MarijuanaOption 1 (118)Option 2 (118)
OPTION 2
Recommend against the Medicinal Use of Marijuana
Gary M. Reisfield, M.D., Robert L. DuPont, M.D.
Marilyn's query should be recognized both for the words — a straightforward question about medicinal marijuana use — and for the music — a plea for symptom relief. Both must be addressed. Although marijuana probably involves little risk in this context, it is also unlikely to provide much benefit. Simply to allow a patient with uncontrolled symptoms of metastatic breast cancer to leave the office with a recommendation to smoke marijuana is to succumb to therapeutic nihilism.6
There is burgeoning interest in the therapeutic potential of targeting the endocannabinoid system. Although most of the research into this system involves the use of specific cannabinoids, a small body of high-quality research shows evidence of clinically significant analgesia from smoked marijuana, primarily for neuropathic pain. There is little evidence to support the use of smoked marijuana for Marilyn's nociceptive pain, and less still for her other symptoms.
Smoked marijuana is a nonmedical, nonspecific, and potentially hazardous method of drug delivery. The cannabis plant contains hundreds of pharmacologically active compounds, most of which have not been well characterized. Each dispensed quantity of marijuana is of uncertain provenance and of variable and uncertain potency and may contain unknown contaminants.
There are other questions to consider in Marilyn's case. Could marijuana's cognitive side effects, particularly its effects on memory, promote or exacerbate chemotherapy-induced cognitive dysfunction? If Marilyn's pulmonary disease includes lymphangitic spread, could smoking cause hypoxemia? What effects will marijuana's potential immunologic hazards (e.g., chemical constituents, pyrolized gases, viable fungal spores, or pesticide residues) have on her health during periods of immunocompromise?7 How will marijuana, alone or in combination with other medications associated with potential cognitive and psychomotor impairment, affect her ability to safely operate a motor vehicle?8 What are the possible effects of marijuana on tumor progression? The putative cannabinoid receptor GPR55 (G-protein–coupled receptor 55) is expressed in human breast cancers, with higher levels of expression correlated with more aggressive phenotypes.9 The marijuana constituent Δ9-THC has been shown in some studies to act as a GPR55 agonist, raising the possibility that it can promote cancer-cell proliferation.10
Two prescription cannabinoids are available, dronabinol (Marinol) (a synthetic Δ9-THC) and nabilone (Cesamet) (a Δ9-THC congener), which are FDA-approved for the treatment of chemotherapy-induced nausea and vomiting. These medications have shown efficacy in the management of pain and distress. In contrast to smoked marijuana, they feature oral administration, chemical purity, precise dosages, and a slower onset but sustained duration of action. They may be less likely than smoked marijuana to induce anxiety, panic, and negative mood states,11 but they have otherwise similar side-effect profiles.
Cannabinoids, however, should be used only as lower-tier therapies for chemotherapy-induced nausea and vomiting, since other medications, such as 5-hydroxytryptamine3-receptor antagonists, dexamethasone, and aprepitant, have superior efficacy and fewer side effects.12
Assure Marilyn — and follow through on the assurance — that throughout her illness she will be accompanied, cared for, and helped to live as well and as long as possible. Reassure her that meticulous attention will be paid to symptom relief. Discuss the patient-specific potential risks and benefits of smoked marijuana and of the administration of pharmaceutical cannabinoids. There is little scientific basis for recommending that she smoke marijuana for symptom control. As Bernard Lown remarked, “Caring without science is well-intentioned kindness, but not medicine.”13
Disclosure forms provided by the author are available with the full text of this article at NEJM.org.
SOURCE INFORMATION
From the University of Florida College of Medicine, Gainesville (G.M.R.); the Institute for Behavior and Health, Rockville, MD (R.L.D.); and Georgetown University School of Medicine, Washington, DC (R.L.D.).
Source: http://www.nejm.org/doi/full/10.1056/NEJMclde1300970#t=cldeOpt2
No comments:
Post a Comment