Topiramate in chronic lumbar radicular pain.

UNLABELLED: Chronic lumbar radicular pain is the most common neuropathic pain syndrome. This was a double-blind, randomized, 2-period crossover trial of topiramate (50 to 400 mg) and diphenhydramine (6.25 to 50 mg) as active placebo to assess the efficacy of topiramate. Each period consisted of a 4-week escalation, a 2-week maintenance at the highest tolerated dose, and a 2-week taper. Main outcome was the mean daily leg pain score on a 0 to 10 scale during the maintenance period. Global pain relief was assessed on a 6-level category scale. In the 29 of 42 patients who completed the study, topiramate reduced leg pain by a mean of 19% (P = .065). Global pain relief scores were significantly better on topiramate (P < .005). Mean doses were topiramate 200 mg and diphenhydramine 40 mg. We concluded that topiramate treatment might reduce chronic sciatica in some patients but causes frequent side effects and dropouts. We would not recommend topiramate unless studies of alternative regimens showed a better therapeutic ratio. PERSPECTIVE: The anticonvulsant topiramate might reduce chronic lumbar nerve root pain through effects such as blockade of voltage-gated sodium channels and AMPA/kainite glutamate receptors, modulation of voltage-gated calcium channels, and gamma-aminobutyric acid agonist-like effects.

Evaluating a hybrid web-based basic genetics course for health professionals.

Health professionals, particularly nurses, continue to struggle with the expanding role of genetics information in the care of their patients. This paper describes an evaluation study of the effectiveness of a hybrid basic genetics course for healthcare professionals combining web-based learning with traditional face-to-face instructional techniques. A multidisciplinary group from the National Institutes of Health (NIH) created "Basic Genetics Education for Healthcare Providers" (BGEHCP). This program combined 7 web-based self-education modules with monthly traditional face-to-face lectures by genetics experts. The course was pilot tested by 186 healthcare providers from various disciplines with 69% (n=129) of the class registrants enrolling in a pre-post evaluation trial. Outcome measures included critical thinking knowledge items and a Web-based Learning Environment Inventory (WEBLEI). Results indicated a significant (p<0.001) change in knowledge scores. WEBLEI scores indicated program effectiveness particularly in the area of convenience, access and the course structure and design. Although significant increases in overall knowledge scores were achieved, scores in content areas surrounding genetic risk identification and ethical issues regarding genetic testing reflected continued gaps in knowledge. Web-based genetics education may help overcome genetics knowledge deficits by providing access for health professionals with diverse schedules in a variety of national and international settings.

Dextromethorphan and memantine in painful diabetic neuropathy and postherpetic neuralgia: efficacy and dose-response trials.

BACKGROUND: There are few repeated dose-controlled trials of N-methyl-d-aspartate glutamate receptor antagonists in patients with neuropathic pain. The authors sought to evaluate two low-affinity N-methyl-d-aspartate antagonists using a novel two-stage design. METHODS: The authors studied patients with painful diabetic neuropathy (DN) and postherpetic neuralgia (PHN) in two crossover trials: (1) efficacy trial (dextromethorphan vs. memantine vs. active placebo [lorazepam]) and (2) dose-response trial of the preferred active drug in responders from the first study (0% vs. 25% vs. 50% vs. 100% of each patient's maximally tolerated dose). Pain intensity was measured on a 20-point scale. RESULTS: Nineteen of 23 DN patients and 17 of 21 PHN patients completed the efficacy trial. Median doses for DN and PHN were 400 and 400 mg/day dextromethorphan, 55 and 35 mg/day memantine, and 1.8 and 1.2 mg/day lorazepam. In the efficacy trial, among patients with DN, dextromethorphan reduced pain intensity by a mean of 33% from baseline, memantine reduced pain intensity by a mean of 17%, and lorazepam reduced pain intensity by a mean of 16%; the proportions of subjects achieving greater than moderate pain relief were 68% with dextromethorphan, 47% with memantine, and 37% with lorazepam. Mean reductions in pain intensity in patients with PHN were 6% with dextromethorphan, 2% with memantine, and 0% with lorazepam. No comparison with placebo reached statistical significance in the efficacy trial. In the 10 DN subjects who responded to dextromethorphan, there was a significant dose-response effect on pain intensity (P = 0.035), with the highest dose significantly better than that of lorazepam (P = 0.03). CONCLUSIONS: Dextromethorphan is effective in a dose-related fashion in selected patients with DN. This was not true of PHN, suggesting a difference in pain mechanisms. Selective approaches to pain-relevant N-methyl-d-aspartate receptors are warranted.