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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.
Resilient Medical Myths: Disproven Precepts that Refuse to Die
Probably every clinician has more than one medical "belief" to which he clings, despite the preponderance of evidence to the contrary. Sometimes, clinical thinking contrary to science persists because of conflicting bodies of evidence, or, as was the subject of this communication, because powerful initial data setsespecially when they fit comfortably with our common-sense judgmentare hard to relinquish even in the face of newer, better science. The recent shock of disillusionment subsequent to the Women's Health Initiative, which did NOT confirm the essentially "assumed" cardiovascular benefits in menopausal women, was a prime example of the disparate information obtainable from observational data (which said that HRT uniformly reduces cardiovascular risk) compared to interventional data (which said that no demonstrable CHD benefit was seen with HRT).
In the 1990s, common wisdom held that vitamin Epurportedly through its antioxidant activityshould be beneficial for reducing vascular events. Indeed, some early reports supported this concept. The HOPE trial, a large randomized interventional trial that included a vitamin E arm, not only failed to show benefit, but tended towards HARM from vitamin E. Subsequently, two meta-analyses conclude that vitamin E is associated with INCREASED mortality.
Tatsioni, et al compared the support stance of authors for utilization of vitamin E in the period immediately after publication of the initial positive trials, and compared this with publications after large data sets had essentially refuted vitamin E benefits. Even 5 years after the best data had refuted vitamin E benefits, a majority of articles addressing the topic still supported the opposite conclusion, although trends in support did decrease over time. Apparently, the progress of science is often difficult for some proponents of opposing ideas to accept. Clinicians will have to be vigilant that outdated or observational data sets not cloud their perceptions of established scientific fact.
Tatsioni A, et al. JAMA. 2007;298(21):2517-2526.
NSAID, Manipulation or Both for LBP
Current knowledge on management of acute low back pain (LBP) suggests that best outcomes are obtained when patients anticipate a favorable outcome, remain active, avoid bed rest, and use acetaminophen for analgesia. NSAIDs used to be considered appropriate first line therapy, but recent heightened awareness of NSAID potential toxicities (GI bleeding, electrolyte disarray, renal dysfunction, BP elevation, and CHD events) mandates that their continued utilization provide meaningful benefits that outweigh such adversity.
Hancock et al studied 240 patients who were randomized to receivein addition to the advice/acetaminopheneither NSAID (diclofenac), spinal manipulation, both, or placebo. Diclofenac was administered 50 mg b.i.d., and spinal manipulation was provided by trained physiotherapists diplomated in manipulative therapy. All subjects were followed for 12 weeks, looking at the number of days until recovery, defined as the first pain-free day, and the first 7 consecutive 7-day period in which the patient reported pain 0-1/10 every day.
Neither diclofenac, spinal manipulation, nor the combination of both was superior to simple first-line advice. Predictable adverse effects of NSAIDs were seen (none serious). Simple first-line tools for management of LBP are not improved by the addition of diclofenac, but adverse events are increased.
Hancock MJ, et al. Lancet. 2007;370:1638-1643.
Pomegranate Juice for Erectile Dysfunction
Pomegranate juice (POM) has attributes that might benefit men with erectile dysfunction (ED), including potent antioxidant activity and enhanced endothelial nitric oxide production. Forest, et al studied the effects of POM when administered as 8 ounces of POM daily vs placebo in men with ED.
Men with mild-moderate ED (n=53) were randomly assigned in a crossover fashion to two 4-week periods of POM or placebo. The primary outcomes assessed at 10 weeks were improvements on the International Index of Erectile Function (IIEF) score and the Global Assessment Questionnaire (GAQ) for sexual dysfunction.
Although there was a trend towards improvement in both GAQ and IIEF in persons receiving POM, it did not achieve statistical significance (p= 0.58). The mean age of the subjects in this pilot study population, 46 years, was younger than usually selected in studies of ED; additionally, the overall ED severity (mild-moderate) was low. The authors consider that perhaps with a larger study population, and longer duration of evaluation, the effects of POM might achieve statistical significance.
Forest CP, et al. Int J Impot Res. 2007;19:564-567.