A Placebo-Controlled Trial of Dextromethorphan as an Adjunct in Opioid-Dependent Patients Undergoing Methadone Maintenance Treatment

Background:

Low-dose dextromethorphan (DM) might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. In a randomized, double-blind, controlled 12 week study, we investigated whether add-on dextromethorphan reduced cytokine levels and benefitted opioid-dependent patients undergoing methadone maintenance therapy (MMT).

Methods:

Patients were randomly assigned to a group: DM60 (60mg/day dextromethorphan; n = 65), DM120 (120mg/day dextromethorphan; n = 65), or placebo (n = 66). Primary outcomes were the methadone dose required, plasma morphine level, and retention in treatment. Plasma tumor necrosis factor (TNF)-α, C-reactive protein, interleukin (IL)-6, IL-8, transforming growth factor–β1, and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8, and 12. Multiple linear regressions with generalized estimating equation methods were used to examine the therapeutic effect.

Results:

After 12 weeks, the DM60 group had significantly longer treatment retention and lower plasma morphine levels than did the placebo group. Plasma TNF-α was significantly decreased in the DM60 group compared to the placebo group. However, changes in plasma cytokine levels, BDNF levels, and the methadone dose required in the three groups were not significantly different.

Conclusions:

We provide evidence—decreased concomitant heroin use—of low-dose add-on DM’s efficacy for treating opioid-dependent patients undergoing MMT.     

Oxytocin Reduces Cocaine Seeking and Reverses Chronic Cocaine-Induced Changes in Glutamate Receptor Function

Background:

Oxytocin, a neurohypophyseal neuropeptide, is a potential mediator and regulator of drug addiction. However, the cellular mechanisms of oxytocin in drug seeking remain unknown.

Methods:

In the present study, we used a self-administration/reinstatement model to study the effects of oxytocin on cocaine seeking and its potential interaction with glutamate function at the receptor level.

Results:

Systemic oxytocin dose-dependently reduced cocaine self-administration during various schedules of reinforcement, including fixed ratio 1, fixed ratio 5, and progressive ratio. Oxytocin also attenuated reinstatement to cocaine seeking induced by cocaine prime or conditioned cues. Western-blot analysis indicated that oxytocin increased phosphorylation of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptor GluA1 subunit at the Ser 845 site with or without accompanying increases in phosphorylation of extracellular signal-regulated kinase, in several brain regions, including the prefrontal cortex, bed nucleus of the stria terminalis, amygdala, and dorsal hippocampus. Immunoprecipitation of oxytocin receptor and GluA1 subunit receptors further demonstrated a physical interaction between these 2 receptors, although the interaction was not influenced by chronic cocaine or oxytocin treatment. Oxytocin also attenuated sucrose seeking in a GluA1- or extracellular-signal-regulated kinase-independent manner.

Conclusions:

These findings suggest that oxytocin mediates cocaine seeking through interacting with glutamate receptor systems via second messenger cascades in mesocorticolimbic regions.     

Etiology of nonresponsive celiac disease: results of a systematic approach

OBJECTIVES: Nonresponse or relapse of symptoms is common in patients with celiac disease treated with gluten free diet. Refractory sprue (RS) is defined as initial or subsequent failure of a strict gluten-free diet to restore normal intestinal architecture and function in patients who have celiac-like enteropathy. The aims of this study were: 1) to identify causes of persistent symptoms in patients referred with presumed diagnosis of nonresponsive celiac disease (NCD); and 2) to characterize patients with true RS. METHODS: Patients were identified who had been systematically evaluated for NCD between January 1997, and May 2001. Patient records and small bowel biopsy results were reviewed. RESULTS: A total of 55 patients were referred with a presumed diagnosis of NCD. Six did not have celiac disease and had other diseases responsible for their symptoms. Diarrhea, abdominal pain, and weight loss were the most common reasons for evaluation in cases of NCD, whereas weight loss, steatorrhea, and diarrhea were the most common presenting features of RS (nine patients). Of the 49 patients with celiac disease, 25 were identified as having gluten contamination. Additional diagnoses accounting for persistent symptoms included: pancreatic insufficiency, irritable bowel syndrome, bacterial overgrowth, lymphocytic colitis, collagenous colitis, ulcerative jejunitis, T-cell lymphoma, pancreatic cancer, fructose intolerance, protein losing enteropathy, cavitating lymphadenopathy syndrome, and tropical sprue. CONCLUSIONS: Based on this study, we conclude the following: 1) gluten contamination is the leading reason for NCD; 2) of NCD cases, 18% are due to RS; and 3) alternative diseases or those coexistent with celiac disease and gluten contamination should be ruled out before a diagnosis of RS is made.     

Left atrial thrombus two years after placement of a left atrial appendage closure device: Unexplored area of the Watchman

A 72‐year‐old man who underwent a left atrial appendage (LAA) closure device 2 years ago presented with atrial flutter with rapid ventricular rate and was referred for cardioversion. Precardioversion transesophageal echocardiogram showed left atrial thrombus and therefore the procedure was aborted. Currently, there is no guideline on imaging surveillance or anticoagulation in patients with LAA closure device who develop intracardiac thrombus after the initial 6‐month surveillance period.     

Dietary factors associated with hyperuricemia in adults

OBJECTIVES: Although diet has long been assumed to be associated with hyperuricemia, the association between diet and hyperuricemia remains to be verified. METHODS: The Nutrition and Health Survey in Taiwan (NAHSIT) implemented between 1993 and 1996 was a nationwide survey using a stratified multistage sampling design. A food frequency questionnaire (FFQ), 24-hour diet recall, and blood samples were utilized. Hyperuricemia was defined as serum urate >7.7 mg/dL for men and >6.6 mg/dL for women. RESULTS: In total, 2176 adults, 987 (45%) men and 1189 (55%) women, were recruited. Mean serum urate was 6.81 +/- 1.66 mg/dL (range, 2.5-16.8 mg/dL) and 5.47 +/- 1.55 mg/dL (range, 1.4-11.5 mg/dL) for men and women, respectively. Multiple logistic regression analysis indicated that beer consumption in both the FFQ and the 24-hour diet recall were significantly associated with hyperuricemia in men after adjusting for age, total caloric intake, body mass index, and geographic area. In FFQ, the adjusted odds ratio was 1.49 for men who imbibed 0.1 to 11.6 g ethanol (<1 standard drink) daily and 1.56 for men who imbibed > or =11.7 g ethanol (> or =1 standard drink) daily, when compared with that for men who did not drink beer (P = 0.035). In the 24-hour diet recall, the adjusted odds ratio for men who drank <5 cans of beer daily was 1.13, and for men who drank > or =5 cans daily was 1.28 when compared with that for men who did not drink beer (P = 0.003). CONCLUSIONS: This cross-sectional survey demonstrated that beer intake is independently associated with increased risk of hyperuricemia in men. Restricted beer intake may help prevent hyperuricemia in the population. The finding of elevated mean serum urate levels over recent decades warrants further study.     

The change of insulin levels after six weeks antidepressant use in drug-naïve major depressive patients

Background

A reciprocal relationship between diabetes risk and depression has been reported. There are few studies investigating glucose–insulin homeostasis before and after short-term antidepressant treatment in drug-naïve major depressive disorder (MDD) patients.

Methods

This study included 104 healthy controls and 50 drug-naïve MDD patients diagnosed according to the DSM-IV criteria. These MDD patients were randomly assigned to receive fluoxetine or venlafaxine for six weeks. Depressive symptoms, body mass index, fasting plasma levels of glucose and insulin were measured.

Results

Compared to the healthy controls, the fasting plasma insulin and the homeostasis model of assessment for pancreatic β-cell secretory function (HOMA-β) was significantly lower in the MDD patients before antidepressant treatment (7.7±4.8 μIU/mL vs. 5.1±4.2 μIU/mL, p=0.006; 114.2±72.3% vs. 74.8±52.0%, p=0.005, respectively). However, these indices were not correlated with depression severity. After 6 weeks of fluoxetine or venlafaxine treatment, the level of HOMA-β borderline significantly increased (108.1±75.5%, p=0.059).

Limitations

The study was limited by the follow-up duration and lack of a placebo group.

Conclusions

Antidepressants might affect insulin secretion independently of the therapeutic effects on MDD. Further studies are needed to investigate the long-term effects of antidepressants on insulin regulation in MDD patients.