Clinical Briefs

By Louis Kuritzky, MD, Clinical Assistant Professor, University of Florida, Gainesville. Dr. Kuritzky is a consultant for GlaxoSmithKline and is on the speaker's bureau of GlaxoSmithKline, 3M, Wyeth-Ayerst, Pfizer, Novartis, Bristol-Myers Squibb, AstraZeneca, Jones Pharma, and Boehringer Ingelheim.

Cannabis withdrawal: Under-recognized

Source: Hasin DS, et al. Cannabis withdrawal in the United States: Results from NESARC. Am J Psychiatry 2008;69:1354-1363.

Opinions on the consequences of marijuana use are wide-ranging: Some experts express grave concern that it may induce COPD, increase risk of lung cancer, promote the emergence of schizophrenia, and lead to "heavy drug" use; others essentially dismiss these (potential) adversities as inadequately established to permit accusations that marijuana has any commonplace serious adverse effects. Like alcohol, where there is an established "dose-response curve," indicating that alcohol in moderation is associated with beneficial health outcomes, as opposed to excessive alcohol, which leads to numerous adverse events, there may be a particular degree of marijuana use that leads to toxicity.

There is no specific DSM-IV diagnostic code for marijuana withdrawal, perhaps reflecting the commonplace observation at the time of its publication that few reports had documented such a specific syndrome. The National Epidemiologic Survey on Alcohol and Related Conditions may change that.

During 2001-2002, live interviews were conducted with frequent cannabis users, defined as at least 3x/wk utilization (n = 2613). To make sure that discontinuation syndromes upon cessation of marijuana were not confounded by discontinuation of other substances sometimes concomitantly used (e.g, alcohol), there was a separate subgroup of "cannabis-only" users (n = 1119).

Frequent marijuana users commonly reported withdrawal symptoms in two primary patterns: a weakness-hypersomnia-psychomotor retardation constellation and an anxiety-restlessness-depression-insomnia cluster.

The incidence of withdrawal was essentially identical among cannabis-only users to that of multi-substance users. Finally, the noted withdrawal symptoms were reported to produce a significant degree of impairment. When presented with such symptoms, clinicians may need to consider marijuana withdrawal.


How long should 'clear sailing' certificate last after colonoscopy?

Source: Imperiale TF, et al. Five-year risk of colorectal neoplasia after negative screening colonoscopy. N Engl J Med 2008;359:1218-1224.

The 2008 guidelines from the American Cancer Society (ACS) have given the green light to support a variety of different colon cancer screening tools, though colonoscopy (COL) continues to have the greatest advocacy from health professionals. The currently recommended interval for re-examination after a negative COL is 10 years in average-risk individuals. Imperiale et al looked at the yield of COL performed 5 years after an initial negative screening COL in average-risk individuals (n = 1256).

Upon rescreening, no cancers were found. Advanced adenomas were found in 1.3%; the relative risk for a new advanced adenoma was 3-fold higher in men than in women.

These data are somewhat surprising when contrasted with a recent study of individuals undergoing two colonoscopies the same day at Indiana University, in which the adenoma miss rate of colonoscopy by experienced endoscopists was 24%! Nonetheless, in neither study does it appear that frank carcinoma was missed. Although this trial does not confirm that a 10-year interval, as recommended by current ACS guideline, is appropriate, it indicates that over a 5-year interval, no new cancers were discovered.


Effect of PUFAs on chronic heart failure

Source: GISSI-HF Investigators. Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): A randomized, double-blind, placebo-controlled trial. Lancet 2008;372:1223-1230.

The pharmacologic treatment of chronic heart failure (CHF) is already complex, often requiring an angiotensin converting enzyme inhibitor or angiotensin receptor blocker, beta blocker, aldosterone antagonist, nitrates, hydralazine, and diuretics. Despite risk reduction with each of these tools, residual risk remains substantial. Polyunsaturated fatty acids (PUFAs) may be another tool to reduce residual risk in CHF.

Some secondary prevention trials of myocardial infarction have indicated risk reduction with PUFAs use, primarily due to prevention of sudden death (attributed to antiarrhythmic properties of PUFAs). Whether similar benefits might be seen in patients with CHF was the subject of this clinical trial.

CHF patients (n = 6975) were enrolled in a randomized placebo-controlled trial of 1 g/d PUFAs (administered as one daily capsule containing eicosapentanoic acid and docosahexanoic acid). At 3.9 years (mean), there was a statistically significant 9% relative risk reduction of all-cause mortality in those who received PUFAs. The tolerability profile of PUFAs was similar to placebo. PUFAs therapy may provide meaningful risk reduction in patients with CHF.