пятница, 10 июня 2011 г.

Перспективы лечения БАР

Excitotoxicity
Several lines of evidence suggest that glutamatergic system dysfunction (eg, N-methyl d-aspartate [NMDA] receptor complex) may play a critical role in the pathophysiology of bipolar disorder. In keeping with this view, the use of glutamatergic modulators may be predicted to alleviate symptoms and modify the disease process. Postmortem studies indicate that altered NMDA receptor complexes are observed in the brain tissue of patients with bipolar disorder. Moreover, genetic polymorphisms for genes implicated in the glutamate receptor complex have been associated with this disorder.6
Riluzole, an inhibitor of glutamate release, is approved by the FDA for the treatment of amyotrophic lateral sclerosis. This agent, at a dosage of 50 to 200 mg/d, was evaluated in an 8-week add-on study in combination with lithium in 14 adults with bipolar depression, 6 of whom had bipolar I disorder, and 8 of whom had bipolar II disorder. Eight patients completed the 8-week trial.6 Significant improvement in depressive symptoms was noted in weeks 5 through 8 as measured by the Montgomery Asberg Depression Rating Scale (MADRS).
Ketamine is a noncompetitive NMDA antagonist that has been evaluated in subanesthetic doses in persons with bipolar disorder.7 Results from a double-blind, randomized, placebo-controlled, crossover study indicate that a single intravenous infusion of ketamine(Drug information on ketamine) combined with lithium or valproate(Drug information on valproate) was capable of alleviating depressive symptoms within 40 minutes of administration when compared with placebo.7 The benefit of ketamine was sustained through day 3. Overall, 71% of patients responded to ketamine and 6% responded to placebo at some point during the trial. Ketamine was not associated with significant increases in hypomania or mania but was associated with dissociative symptoms.

Cyclooxygenase-2 (COX-2) inhibitors have been shown to protect against glutamate-induced neurotoxicity; to prevent normal aging-related increases of cytokines, prostaglandins, and TNF in neurons; and to modulate the hypothalamic adrenal axis.10 The COX-2 inhibitor celecoxib(Drug information on celecoxib) was evaluated as a potential antidepressant in adults with bipolar I/II depression (N = 28).10 This drug was administered at a dosage of 400 mg daily in combination with a mood stabilizer or antipsychotic medication as part of a 6-week, randomized, double-blind, placebo-controlled study. Depressive symptoms in both the treatment group and the placebo group improved, with a statistically significant (P = .01) advantage at week 1 in patients treated with celecoxib compared with patients who received placebo. Although there was an advantage in favor of the treatment group at week 1, both the active-treatment and placebo groups had similar reductions for each of the remaining observation points.

Several case reports and case series suggest that insulin sensitizers (eg, rosiglitazone(Drug information on rosiglitazone)) may offer an antidepressant effect in persons with major depressive disorder. Studies are currently under way in bipolar disorder. For example, several studies are evaluating the antidepressant effects of intranasal insulin and insulin secretagogues (eg, incretins) in bipolar disorder. Moreover, there is ongoing research to determine whether weight loss, bariatric surgery, and dietary modification (eg, ketogenic diet) improve depressive symptoms in persons with bipolar disorder.

Results from a randomized, double-blind, multicenter, placebo-controlled study of adults with bipolar disorder (N = 75) indicate that N-acetylcysteine (1 g bid) adjunctive to usual medications was capable of alleviating depressive symptoms as measured by the MADRS.14 The benefit on depressive symptoms was noted at week 20 as part of this 24-week study. Benefits were noted by week 8 on the Global Assessment of Functioning Scale and Social and Occupational Functioning Assessment Scale. N-acetylcysteine did not induce hypomania or mania and was well tolerated. Adverse events reported in more than 15% of the N-acetylcysteine group included change in energy, headaches, heartburn, and increased joint pain.

Armodafinil is the longer-lasting isomer of modafinil, and its therapeutic indications are similar to those of the racemic agent modafinil. Armodafinil at a dosage of 150 mg/d was evaluated as an antidepressant in adults with bipolar disorder who received either olanzapine, lithium, or valproic acid as part of an 8-week double-blind placebo-controlled study.

Novel Treatment Avenues for Bipolar Depression

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