Chronic neuropathic pain affects 1%-2% of the adult population and is often refractory to standard pharmacologic treatment. Patients with chronic pain have reported using smoked cannabis to relieve pain, improve sleep and improve mood.
METHODS: Adults with post-traumatic or postsurgical neuropathic pain were randomly assigned to receive cannabis at four potencies (0%, 2.5%, 6% and 9.4% tetrahydrocannabinol) over four 14-day periods in a crossover trial. Participants inhaled a single 25-mg dose through a pipe three times daily for the first five days in each cycle, followed by a nine-day washout period. Daily average pain intensity was measured using an 11-point numeric rating scale. We recorded effects on mood, sleep and quality of life, as well as adverse events.
RESULTS: We recruited 23 participants (mean age 45.4 [standard deviation 12.3] years, 12 women [52%]), of whom 21 completed the trial. The average daily pain intensity, measured on the 11-point numeric rating scale, was lower on the prespecified primary contrast of 9.4% v. 0% tetrahydrocannabinol (5.4 v. 6.1, respectively; difference = 0.7, 95% confidence interval [CI] 0.02-1.4). Preparations with intermediate potency yielded intermediate but nonsignificant degrees of relief. Participants receiving 9.4% tetrahydrocannabinol reported improved ability to fall asleep (easier, p = 0.001; faster, p < 0.001; more drowsy, p = 0.003) and improved quality of sleep (less wakefulness, p = 0.01) relative to 0% tetrahydrocannabinol. We found no differences in mood or quality of life. The most common drug-related adverse events during the period when participants received 9.4% tetrahydrocannabinol were headache, dry eyes, burning sensation in areas of neuropathic pain, dizziness, numbness and cough.
CONCLUSION: A single inhalation of 25 mg of 9.4% tetrahydrocannabinol herbal cannabis three times daily for five days reduced the intensity of pain, improved sleep and was well tolerated. Further long-term safety and efficacy studies are indicated.
Day: 11/19/2010
Lung Cancer Risk in HIV: Don’t Just Blame the Smoking
Cigarette smoking is highly prevalent among HIV-positive individuals, but it doesn’t seem to entirely explain the increased risk for lung cancer in this population.
Prior studies have suggested that the association between HIV infection and lung cancer risk is independent of the high rate of cigarette smoking observed among HIV-positive people. To explore this possibility further, investigators evaluated data from a large prospective cohort study of injection-drug users (IDUs) in Baltimore.
The analysis involved 2495 adult IDUs (74% men; 94% black) who were followed for at least 2 years; 740 were HIV-positive at baseline, and an additional 332 seroconverted during follow-up. Almost all study participants were current or past smokers.
During follow-up, 29 study participants developed lung cancer; 13 of them were HIV-positive, with a median CD4 count of 267 cells/mm3. The risk for lung cancer was twice as high among HIV-positive individuals as among HIV-negative individuals, and this held true even after adjustment for the average number of cigarettes smoked per day. Among people who smoked similar amounts (<1.4 packs per day), HIV-positive individuals were 3.5 times more likely to develop lung cancer than HIV-negative individuals.
Twenty-six individuals with lung cancer died during follow-up. The HIV-positive patients with lung cancer had a shorter median survival time than the HIV-negative patients (0.39 years vs. 0.72 years) — and also had a lower 1-year survival rate (18% vs. 42%). However, in a multivariate analysis, mortality risk was not significantly elevated among HIV-positive versus HIV-negative patients with lung cancer (hazard ratio, 3.8; 95% confidence interval, 0.92–15).
Comment: Although this study was small, the findings suggest that HIV-positive individuals have an increased risk for lung cancer that may not be entirely explained by smoking. Nonetheless, tobacco use is the primary driver of lung cancer, and in that regard, these findings serve as yet another reminder to discuss smoking cessation with patients. It’s a tangible intervention that can lower a patient’s risk for developing and succumbing to this and many other types of cancers.
Published in Journal Watch HIV/AIDS Clinical Care November 15, 2010
Tricyclics Lighten Headache Burden in Patients with Migraine and Tension Headaches
Tricyclics are more effective than selective serotonin reuptake inhibitors.
For decades, clinicians have prescribed tricyclic antidepressant drugs for patients with migraine and tension headaches. In this meta-analysis of 37 randomized trials (average duration, 10 weeks) involving nearly 3200 patients (73% women; mean age, 40), investigators compared the efficacy of tricyclics with that of placebo, selective serotonin reuptake inhibitors (SSRIs), and β-blockers in the treatment of migraine and tension headaches. Amitriptyline and clomipramine were the most common tricyclics in the trials.
Tricyclics were compared with placebo in 20 trials. Tricyclics were significantly more effective than placebo in reducing the burden of both headache types: Tricyclics reduced the mean number of headaches monthly by 1.4 for migraine (from a baseline of 4.7) and by 6.9 for tension headache (from a baseline of 16.9). For both headache types, tricyclics were more likely to result in at least 50% improvement in patients’ headaches and to result in fewer doses of analgesics. Furthermore, the beneficial effect of tricyclics strengthened with time.
In the eight trials in which tricyclics were compared with SSRIs, tricyclics were more likely to result in at least 50% improvement in both migraine and tension headaches. Three trials compared tricyclics and β-blockers for migraine; both classes of drugs were similarly effective. Although patients taking tricyclics experienced more side effects (e.g., dry mouth) than patients taking placebo or SSRIs, side effects did not result in increased dropout rates.
Comment: Tricyclics are more effective than placebo and SSRIs in reducing headache burden in patients with migraine and tension headaches and were similar to β-blockers for migraine prophylaxis. Unfortunately, few rigorous head-to-head clinical trials have compared tricyclics to valproic acid and topiramate, both of which are FDA-approved for migraine prophylaxis.
— Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine November 18, 2010
ARYAN'S BLOG 