Стратегии потенцирования действия клозапина

Background. When schizophrenia patients have insufficient response to clozapine, pharmacological augmentation is often applied. This meta-analysis summarizes available evidence on efficacy of pharmacological augmentation of clozapine treatment in schizophrenia spectrum disorder.

Methods. Only double-blind randomized controlled studies were included. Primary outcome measure was total symptom severity, and secondary outcome measures were subscores for positive and negative symptoms. Effect sizes were calculated from individual studies and combined to standardized mean differences (Hedges's g). Results. Twenty-nine studies reporting on 15 different augmentations were included. Significant better efficacy than placebo on total symptom severity was observed for lamotrigine, citalopram, sulpiride, and CX516 (a glutamatergic agonist). The positive effect of lamotrigine disappeared after outlier removal. The other positive findings were based on single studies. Significantly better efficacy on positive symptom severity was observed for topiramate and sulpiride. The effect of topiramate disappeared after outlier removal.

Results for sulpiride were based on a single randomized controlled trial. Citalopram, sulpiride, and CX516 showed better efficacy for negative symptoms than placebo, all based on single studies.

Conclusions. Evidence for efficacy of clozapine augmentation is currently scarce. Efficacy of lamotrigine and topiramate were both dependent on single studies with deviating findings. The effect of citalopram, sulpiride, and CX516 were based on single studies. Thus, despite their popularity, pharmacological augmentations of clozapine are not (yet) demonstrated to be superior to placebo.

 Pharmacological Augmentation Strategies for Schizophrenia Patients With Insufficient Response to Clozapine: A Quantitative Literature Review

Антиконвульсанты при тревожных расстройствах

Can Anticonvulsants Help Patients With Anxiety Disorders?

Коррекция метаболических побочных эффектов антипсихотиков

This systematic review and meta-analysis included 32 randomized, open and double-blind, placebo-controlled studies (mean duration: 13.1 weeks, range: 6-16 weeks) with a total of 1482 subjects and which tested the following 15 medications: amantadine, dextroamphatamine, d-fenfluramine, famotidine, fluoxetine, fluvoxamine, metformin, nizatidine, orlistat, phenylpropanolamine, reboxetine, rosiglitazone, sibutramine, topiramate, and metformin plus sibutramine).
Five of the agents assessed lead to significantly greater weight loss than placebo. The greatest weight loss was achieved with metformin (N = 7, n = 334, -2.94 kg [CI, -4.89, -0.99]), followed by d-fenfluramine (N = 1, n = 16, -2.60 kg [CI,-5.14, -0.06]), sibutramine (N = 2, n = 55, -2.56 kg [CI, -3.91, -1.22]), topiramate (N = 2, n = 133, -2.52, [CI, -4.87, -0.16]) and reboxetine (N = 2, n = 79, -1.90 kg [CI, -3.07, -0.72]). Nausea rates did not differ between treatment and placebo groups. Results on the secondary outcome measures of waist circumference and weight gain, carbohydrate metabolism and blood lipids as well as sensitivity analysis regarding prevention vs intervention trials were largely heterogeneous. No significant differences between treatment and placebo groups were found for the secondary outcome measures of psychiatric symptoms and adverse events.

The Year in Psychosis and Bipolar Disorder: Treating Antipsychotic-related Metabolic Abnormalities

Evidence supporting antiepileptics for mood disorders and schizophrenia

Medication	Bipolar disorder			Major depressive disorder	Schizophrenia
	Mania	Depression	Maintenance
Carbamazepine					(aggression, impulsivity)
Lamotrigine					(adjunct to clozapine)
Valproate					(aggression, impulsivity)
Gabapentin
Levetiracetam
Oxcarbazepine
Tiagabine
Topiramate
Zonisamide
	: strong evidence supporting efficacy;
	: moderate evidence supporting efficacy;
	: weak evidence supporting efficacy
Source: For an extensive bibliography of studies that support these recommendations, see this article at CurrentPsychiatry.com

Table 2
Off-label use of antiepileptics for various psychiatric disorders

Condition/disorder	Possible medication(s)*
Alcohol withdrawal/relapse prevention	Carbamazepine, topiramate, valproate
Benzodiazepine withdrawal	Carbamazepine, valproate
Binge eating disorder	Topiramate, zonisamide
Bulimia nervosa	Topiramate
Drug dependence/abstinence	Carbamazepine, lamotrigine, topiramate, tiagabine
Generalized anxiety disorder	Pregabalin, tiagabine
Obesity	Lamotrigine, topiramate, zonisamide
Panic disorder	Valproate
Posttraumatic stress disorder	Lamotrigine
Social phobia	Gabapentin, pregabalin
* Based on small randomized controlled trials, open-label trials, or case reports. Further investigation in large systematic trials is needed

Explain to patients taking topiramate or zonisamide that increasing their fluid intake will significantly reduce kidney stone risk

The FDA recently announced a warning of a risk of aseptic meningitis with lamotrigine.11 In 40 reported cases, symptoms—headache, fever, nausea, vomiting, nuchal rigidity, rash, photophobia, and myalgias—occurred between 1 and 42 days of treatment and typically resolved after lamotrigine was withdrawn. In 15 patients in whom lamotrigine was re-initiated, meningitis symptoms returned quickly and with greater severity.

Antiepileptics for psychiatric illness: Find the right match

Потенциирование клозапина: сульпирид, амисульприд, ламотриджин

A frequent treatment strategy for clozapine-resistant patients with schizophrenia is the use of specific augmentors that are suitable for adjunctive therapy. Clozapine is a polyvalent drug but it lacks high-potency dopamine receptor blockade (Kerwin & Osborne, 2000). Therefore, there has been interest in using as augmentors substituted benzamides with highly selective dopamine receptor blocking profiles (Kerwin, 2000). Augmentation strategies incorporating sulpiride are well documented. The authors of one study of sulpiride augmentation in 28 patients partially responsive to clozapine (Shiloh et al, 1997) noted a mean reduction of about 40–50% in various clinical response scores (Brief Psychiatric Rating Scale and Scale for the Assessment of Positive Symptoms).

Several groups have been interested in mimicking this study with amisulpride, a relative of sulpiride that is even more selective at the dopamine D2 receptor. A case series by Zink et al(2004) showed improvement in previously treatment-resistant symptoms following a combined treatment strategy of clozapine and amisulpride. In addition, our group performed an open trial of amisulpride augmentation in a long-term (52 weeks) study. Significant improvement was observed in half of the patients, with no additional side-effects. Moreover, this study monitored plasma levels to determine whether this was a pharmacokinetic interaction. Clozapine levels did not change throughout the duration of the trial, suggesting a pharmacodynamic interaction (Munro et al, 2004).

Augmentation with anti-epileptics
A glutamate hyperfunction hypothesis of schizophrenia has generated interest in the role of glutamate release inhibitors as clozapine augmentors. In a study of 26 treatment-resistant patients receiving lamotrigine (17) or topirimate (9) in addition to their existing antipsychotic treatment (a variety of antipsychotics), a significant improvement was observed when lamotrigine was added to risperidone, haloperidol, olanzapine or flupenthixol. However, no significant effect was observed in patients receiving topirimate augmentation in addition to clozapine, olanzapine, haloperidol or flupenthixol (Dursun & Deakin, 2001). The therapeutic effects of lamotrigine augmentation were also assessed in a rigorous randomised placebo-controlled cross-over study of 34 clozapine-resistant patients (Tiihonen et al, 2003). In this 14-week study, lamotrigine treatment significantly improved positive symptoms and general psychopathological symptoms, but had no effect on negative symptoms. The authors suggested that this was the first time a non-dopamine antagonist had proven efficacy in schizophrenia, giving further credence to the hyperglutamate neurotransmission hypothesis for the generation of positive symptoms in the disorder.

Management of clozapine-resistant schizophrenia

Глутаматергические механизмы ОКР

Glutamatergic Dysfunction in Obsessive-Compulsive Disorder and the Potential Clinical Utility of Glutamate-Modulating Agents

Прегабалин при ГТР

"These results indicate that pregabalin is an effective, rapidly acting, and safe treatment for generalized anxiety disorder. In short-term treatment, pregabalin does not appear to have the withdrawal symptoms associated with the benzodiazepines."

Pregabalin in Generalized Anxiety Disorder: A Placebo-Controlled Trial

"The dose of 150 mg pregabalin over the four weeks of the trials was found insufficient for the treatment of GAD. In the dose range of 200-450 mg daily, a clinically significant effect was obtained, although with a plateau-like curve which was not increased for the maximum dose of 600 mg daily."

Dose-response relationship of pregabalin in patients with generalized anxiety disorder. A pooled analysis of four placebo-controlled trials.

"The efficacy of pregabalin in treating GAD is not surprising as a number of other antiepileptic drugs have also been shown to have anxiolytic properties and to be effective in treating patients with anxiety disorders. Valproate has been shown to have efficacy in the treatment of panic disorder (Primeau et al 1990; Woodman and Noyes 1994; Baetz and Bowen 1998) and blocks lactate-induced panic attacks (Keck et al 1993). The antiepileptic drug carbamazepine has efficacy in the treatment of panic disorder (Tondo et al 1989), post-traumatic stress disorder (PTSD) (Lipper et al 1986), and obsessive compulsive disorder (OCD) (Joffe and Swinson 1987). Lamotrigine is potentially effective in the treatment of PTSD (Hertzberg et al 1999) and may have an adjunctive role in the treatment of refractive OCD (Kumar and Khanna 2000). Topiramate has been shown to be efficacious in open-label trials for PTSD (Berlant and van Kammen 2002; Berlant 2004), social phobia disorder (Van Ameringen et al 2004) and may have an adjunctive role in treatment-resistant OCD (Van Ameringen et al 2006). However, unlike previous antiepileptic drugs which primarily block sodium and potassium channels or increase cerebral GABA concentrations, pregabalin decreases presynaptic calcium currents and in doing so decreases the release of several neurotransmitters, including glutamate (Dooley et al 2000a), substance P (Fehenbacher et al 2003), calcitonin-gene-related peptide (Fehenbacher et al 2003), and norepinephrine (Dooley et al 2002). Interestingly, many of these neurotransmitters have been implicated in the pathogenesis GAD or other anxiety disorders (Erikkson et al 1991; Geracioti et al 2001; Olsson et al 2004; Geracioti et al 2006). As might be expected, agents that pharmacologically dampen these systems have therapeutic roles in a number of anxiety disorders (Peet and Ali 1986; Furmark et al 2005; Strawn and Geracioti 2006). Also, decreases in the activity of these or related “fear circuits” that underlie the pathophysiology of certain anxiety disorders (Stahl 2004) could explain the efficacy of pregabalin in patients with GAD. It will be of interest to examine the effects of pregabalin in other anxiety disorders such as PTSD, panic disorder, or even meal-related anxiety in anorexia nervosa (wherein additional benefit may be conferred by pregabalin-associated weight gain)."

The treatment of generalized anxiety disorder with pregabalin, an atypical anxiolytic

Влияние современных антиконвульсантов на когнитивные функции

"BACKGROUND: Antiepileptic drugs (AEDs) can be associated with neurotoxic side effects including cognitive dysfunction, a problem of considerable importance given the usual long-term course of treatment. Pregabalin is a relatively new AED widely used for the treatment of seizures and some types of chronic pain including fibromyalgia. We measured the cognitive effects of 12 weeks of pregabalin in healthy volunteers. METHODS: Thirty-two healthy volunteers were randomized in a double-blind parallel study to receive pregabalin or placebo (1:1). Pregabalin was titrated over 8 weeks to 600 mg/d. At baseline, and after 12 weeks of treatment, all subjects underwent cognitive testing. Test-retest changes in all cognitive and subjective measures were Z scored against test-retest regressions previously developed from 90 healthy volunteers. Z scores from the placebo and pregabalin groups were compared using Wilcoxon tests. RESULTS: Thirty subjects completed the study (94%). Three of 6 target cognitive measures (Digit Symbol, Stroop, Controlled Oral Word Association) revealed significant test-retest differences between the pregabalin and placebo groups, all showing negative effects with pregabalin (p < 0.05). These cognitive effects were paralleled by complaints on the Portland Neurotoxicity Scale, a subjective measure of neurotoxicity (p < 0.01). CONCLUSION: At conventional doses and titration, pregabalin induced mild negative cognitive effects and neurotoxicity complaints in healthy volunteers. These effects are one factor to be considered in the selection and monitoring of chronic AED therapy. Class of Evidence: This study provides Class I evidence that pregabalin 300 mg BID negatively impacts cognition on some tasks in healthy volunteers."

Cognitive effects of pregabalin in healthy volunteers: a double-blind, placebo-controlled trial.

"OBJECTIVE: To evaluate the cognitive effects of topiramate (TPM) and gabapentin (GBP). METHODS: Forty healthy volunteers were randomized to a 12-week course of TPM, GBP, or placebo. Doses were gradually escalated over 10 weeks to a maximum of 400 mg/day of TPM or 3,600 mg/day of GBP or to the highest tolerated dose. Subjects were interviewed and examined biweekly. Cognitive testing was performed prior to initiating the drug and again 12 weeks later, at least 2 weeks after achieving plateau dosing. For each subject and cognitive measure, test-retest Z scores were calculated based on regression equations derived from 73 healthy volunteers. Group comparisons utilized the Wilcoxon test. RESULTS: There were significant TPM vs GBP and TPM vs placebo differences in test-retest Z scores for four of six target cognitive measures (Digit Symbol, Story Recall, Selective Reminding, Controlled Oral Word Association), always indicating worse retest performance for subjects receiving TPM. Overall, 12 of 24 cognitive measures were similarly affected. TPM effects were large, and several target measures averaged >2 SD of negative change. One measure was significantly affected by GBP. CONCLUSIONS: Topiramate (TPM) impaired cognitive test performance, whereas gabapentin had minimal effects. The effects of TPM were of sufficient magnitude potentially to affect daily and occupational function."

Effects of topiramate and gabapentin on cognitive abilities in healthy volunteers.

Эффективность метформина и топирамата в снижении набора веса вызванного терапией атипичными антипсихотиками

OBJECTIVE: To review the literature describing the efficacy of metformin and topiramate for the treatment of second-generation antipsychotic–induced weight gain.

DATA SOURCES: Articles were identified by searching the MEDLINE database (from 1949 through January 2010) using the key words metformin, topiramate, antipsychotic, weight, weight gain, and obesity.

STUDY SELECTION AND DATA EXTRACTION: All randomized, placebo-controlled trials of metformin and topiramate were selected for review.

DATA SYNTHESIS: Weight gain due to second-generation antipsychotic use is a concern due to the risk of long-term metabolic and cardiovascular effects with these agents. These effects include obesity, hyperglycemia, and insulin resistance, all of which may contribute to diabetes and cardiovascular disease. Second-generation antipsychotics vary in the degree to which they cause weight gain, and dietary and lifestyle changes may not be feasible or sufficient in counter-acting this weight gain. Although other pharmacologic agents may be beneficial to prevent and treat antipsychotic-induced weight gain, metformin and topiramate have been the most extensively studied in this setting. Metformin acts peripherally to cause weight loss, while topiramate acts centrally. Review of 11 randomized, controlled trials demonstrates beneficial effects of metformin and topiramate in prevention and treatment of weight gain. Metformin is generally well tolerated and has been studied in pediatric patients, while topiramate is associated with more drug interactions and may possibly interfere with control of schizophrenia.

CONCLUSIONS: Data for the use of metformin and topiramate in the treatment and prevention of second-generation antipsychotic–induced weight gain are limited. Both may be effective in helping patients lose weight via mechanisms that have yet to be clearly defined. The use of metformin results in greater weight loss than topiramate, and topiramate is associated with more risks and may compromise the treatment of schizophrenia. Treatment of antipsychotic-induced weight gain with metformin may be an option after lifestyle and dietary changes have failed.

Efficacy of Metformin and Topiramate in Prevention and Treatment of Second-Generation Antipsychotic–Induced Weight Gain