A single-blinded case-control study of memantine in severe obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a common debilitating psychiatric illness that typically improves but does not remit with first-line medication and behavioral treatments. Serotonergic agents including selective serotonin reuptake inhibitors and clomipramine have provided the mainstay of OCD medication management for decades. Combined dopamine/serotonergic agents such as atypical antipsychotics are presently the only OCD-augmenting strategies proven effective via randomized controlled trials. Despite increasing evidence for a pathogenic role of glutamate in OCD, no controlled trials of glutamatergic augmenting agents have been reported. METHODS: An intent-to-treat sample included 44 subjects receiving standard treatment at the McLean/Massachusetts General Hospital Intensive Residential Treatment (IRT) program, 22 of whom also received memantine augmentation. Admission, monthly and discharge measures of OCD, depression, and psychosocial functioning were collected by raters blinded to augmentation status. Matched controls were selected based on sex, initial OCD severity, psychosocial functioning, and timing of admission. The Clinical Global Improvement Scale captured global clinical change. RESULTS: Mean (SD) Yale-Brown Obsessive Compulsive Scale score decreases were 7.2 (6.4) among the cases and 4.6 (5.9) among the matched controls, reflecting mean clinical improvement among the cases (27.0% decrease) but not the controls (16.5% decrease). Mean (SD) depression severity score decreases were 5.8 (9.5) among the cases and 4.7 (9.9) among the controls. Initial intrusive obsessions were significantly more severe among marked responders compared with limited response or nonresponse cases (4.4 vs 2.9; t = 2.15; P = 0.048). CONCLUSIONS: This study provides preliminary supportive evidence for the effectiveness of memantine as a glutamatergic augmenting agent in severe OCD. Future randomized double-blind placebo-controlled trials are warranted.

The combined effects of memantine and fluoxetine on an animal model of obsessive compulsive disorder.

Obsessive Compulsive Disorder (OCD) is currently treated with behavioral modification and psychotropic medications, with varying degrees of success. The most popular drugs for the treatment of OCD are the selective serotonin reuptake inhibitors (SSRIs). Another drug, the N-methyl-d-aspartate antagonist memantine, has recently been tested in the treatment of OCD. The present study investigates the effect of fluoxetine and memantine alone and in combination in a mouse model of compulsive behavior. In this model, compulsive scratching is induced by a subcutaneous injection of serotonin or a serotonin releasing agent, compound 48-80, in the back of the neck. The effects of the memantine and fluoxetine combination were found to synergistic, specifically as defined by an isobologram. The results of the present investigation suggest the potential of a more effective management of the symptoms of OCD.

SAR of psilocybin analogs: discovery of a selective 5-HT 2C agonist.

An SAR study of psilocybin and psilocin derivatives reveals that 1-methylpsilocin is a selective agonist at the h5-HT(2C) receptor. The corresponding phosphate derivative, 1-methylpsilocybin, shows efficacy in an animal model for obsessive-compulsive disorder, as does 4-fluoro-N,N-dimethyltryptamine. These results suggest a new area for development of novel 5-HT(2C) agonists with applications for drug discovery.

Antihyperalgesic effect of simultaneously released hydromorphone and bupivacaine from polymer fibers in the rat chronic constriction injury model.

We aimed to evaluate the antihyperalgesic efficacy of a combination of hydromorphone (HM) and bupivacaine (BP) delivered via controlled release from a biodegradable cylindrical rod. In vivo studies were performed using a rat model of thermal hyperalgesia induced by chronic constriction injury (CCI) of the sciatic nerve with loose ligatures. Poly(lactic-co-glycolic acid) (PLGA) rods (10 mm length, 1 mm diameter) loaded with HM (5 mg per rod), BP (5 mg per rod) or no drug (placebo) were implanted subcutaneously, in single or dual pairs, adjacent to the constriction injury, immediately after nerve ligation. We evaluated the efficacy of two dose levels for each drug, alone or in combination, in attenuating thermal hyperesthesia over a period of 12 days according to a prevention protocol. Plasma levels of drugs released from the rods and also released in an in vitro simulation were evaluated. In vitro studies demonstrated that drug release is maintained for at least 10 days. HM (5 mg) alone and BP (5 mg) alone did not attenuate hyperalgesia. Their combination provided a significant increase in the paw withdrawal latency as compared to single agents or placebo. When the dose in each group was doubled, implanting four rods, significant attenuation of hyperalgesia was observed. Analyses of rods retrieved after termination of experiments (after 12 days) revealed 30% residual HM and 70% residual BP content. Prolonged delivery of HM and BP alone or in combination via locally applied PLGA rods may offer a feasible alternative to provide long-lasting analgesia.