Эффективность использования высоких доз антидепрессантов

Higher doses than those currently used might be modestly more effective, but come with higher risks of adverse effects.

Before writing medications off as ineffective or only partially effective, clinicians strive to optimize dosing. To better identify optimal doses for six selective serotonin reuptake inhibitors (SSRIs), investigators applied meta-analytic techniques to 40 studies involving 10,039 patients with major depression in placebo-controlled randomized trials who were treated with fluoxetine, (N=2386), fluvoxamine (N=910), paroxetine (N=3424), sertraline (N=865), citalopram (N=1349), or escitalopram (N=1105).

Focusing on efficacy and tolerability, investigators calculated number needed to treat (NNT) and number needed to harm (NNH). They used published dose ranges to convert SSRI doses to imipramine equivalents, with 100 mg of imipramine equivalent to:

Sertraline, 120 mg

Fluvoxamine, 100 mg

Paroxetine, 20 mg

Fluoxetine, 20 mg

Citalopram, 33.3 mg

Escitalopram, 16.7 mg

Statistical modelling adjusted for lag times of medication-effect onsets and for doses used in the trials (100–400 mg of imipramine equivalents). In dose-by-time interaction analyses, higher doses yielded greater therapeutic responses. Greatest efficacy was seen for 200–250-mg imipramine equivalents, compared with higher and lower ranges (NNTs: compared with placebo, 3; in lower-dose comparisons, 14–16). Compared with low doses, higher dose was associated with greater likelihood of dropout due to adverse effects (NNHs, 45–48), but all-cause dropouts were fewer at higher doses, presumably due to efficacy. Fluvoxamine, approved for depression in other countries but not by the FDA, was excluded in some analyses, which yielded similar overall results.

Comment

These findings generally support the use of higher dose ranges for several SSRIs for major depression that did not respond or only partially responded to SSRIs. Most clinicians treating obsessive-compulsive disorder and bulimia nervosa are already comfortably using these higher doses. However, distinctions among SSRIs are warranted; for example, the FDA has issued warnings about QTc interval prolongation with higher doses of citalopram.

 Optimal Doses for SSRIs in Treating Depression: Meta-Analytic Results

Связь вариаций CYP2C19 с риском аритмий при приёме циталопрама и эсциталопрама

Recently, a FDA Safety Communication warned of a dose-dependent risk for QTc prolongation with citalopram, which is metabolized by CYP2C19 of the cytochrome P450 system. We investigate associations between citalopram and escitalopram dose, serum concentration, CYP2C19 phenotype, and QTc. We undertook a retrospective chart review of citalopram or escitalopram patients with the inclusion criteria of consistent medication dose, CYP2C19 phenotype (extensive metabolizers [EM], intermediate metabolizers [IM], poor metabolizers [PM]), and QTc interval on ECG. We further identified 42 citalopram users with citalopram serum concentration measurements and ECG. Regression and one-way ANOVA were used to examine the relationship between citalopram dose, citalopram serum concentration, CYP2C19 phenotype, and QTc interval. Of 75 citalopram patients, the EM group had significantly shorter QTc intervals than a combined IM+PM group (427.1±23.6 ms vs. 440.1±26.6 ms, one-tailed t-test, p=0.029). In the 80 escitalopram cohort, there was no significant difference in QTc between phenotype groups. There was no statistical correlation between citalopram (p=0.62) or escitalopram (p=0.30) dose and QTc. QTc was not associated with citalopram serum level (p=0.45). In contrast to the FDA warning, this study found no association between citalopram/escitalopram dose and QTc. However, PM of the drug tended to have longer QTc intervals. Our findings suggest cytochrome P450 genotyping in select patients may be helpful to guide medication optimization while limiting harmful effects.

CYP2C19 variation, not citalopram dose nor serum level, is associated with QTc prolongation

Антидепрессивный эффект стимуляции NMDA функции схож с эффектом кетамина

Philadelphia, PA, November 18, 2013– Thirteen years ago, an article in this journal first reported that the anesthetic medication, ketamine, showed evidence of producing rapid antidepressant effects in depressed patients who had not responded to prior treatments. Ketamine works by blocking one of the targets for the neurotransmitter glutamate in the brain, the N-methyl-D-aspartate (NMDA) glutamate receptor.

Now, a new study in Biological Psychiatry reports that enhancing, instead of blocking, that same target – the NMDA glutamate receptor – also causes antidepressant-like effects.

Scientists theorize that NMDA receptor activity plays an important role in the pathophysiology of depression, and that normalizing its functioning can, potentially, restore mood to normal levels.

Prior studies have already shown that the underlying biology is quite complex, indicating that both hyperfunction and hypofunction of the NMDA receptor is somehow involved. But, most studies have focused on antagonizing, or blocking, the receptor, and until now, studies investigating NMDA enhancement have been in the early phases.

Sarcosine is one such compound that acts by enhancing NMDA function. Collaborators from China Medical University Hospital in Taiwan and the University of California in Los Angeles studied sarcosine in an animal model of depression and, separately, in a clinical trial of depressed patients.

“We found that enhancing NMDA function can improve depression-like behaviors in rodent models and in human depression,” said Dr. Hsien-Yuan Lane, the corresponding author on the article.

In the clinical portion of the study, they conducted a 6-week trial where 40 depressed patients were randomly assigned to receive sarcosine or citalopram (Celexa), an antidepressant already on the market that was used as a comparison drug. Neither the patients nor their doctors knew which one they were receiving.

Compared to citalopram, patients receiving sarcosine reported significantly improved mood scores, were more likely to experience relief of their depression symptoms, and were more likely to continue in the study. There were no major side effects in either group, but patients receiving citalopram reported more relatively minor side effects than the patients being treated with sarcosine.

“It will be important to understand how sarcosine, which enhances NMDA receptor function, produces the interesting effects reported in this study. There are ways that its effects, paradoxically, might converge with those of ketamine, a drug that blocks NMDA receptors,” commented Dr. John Krystal, Editor of Biological Psychiatry. “For example, both compounds may enhance neuroplasticity, the capacity to remodel brain networks through experience. Also, both potentially attenuate signaling through NMDA receptors, ketamine with single doses and sarcosine, with long-term administration, by evoking an adaptive down regulation of NMDA receptors.”

Would an “Anti-Ketamine” Also Treat Depression? 

Скополамин и циталопрам в терапии депрессии

Evidence is accumulating that cholinergic pathways in the brain help to regulate mood, and researchers have shown that intravenous scopolamine (an anticholinergic) is effective for moderate-to-severe depression (JW Psychiatry Mar 29 2010). This 6-week, Iranian, double-blind study tested whether oral scopolamine (0.5 mg twice daily), added to citalopram as an initial treatment produces greater antidepressant effects than citalopram plus placebo. Participants were 40 patients with moderate-to-severe major depression (baseline score on the 17-item Hamilton Rating Scale for Depression, 22).
At days 4, 28, and 42, patients receiving scopolamine augmentation had significantly greater reduction in symptoms than patients taking add-on placebo, with an overall large effect size (0.9). Response rates were higher with scopolamine than placebo at week 4 (65% vs. 30%) but not at week 6. Remission rates for scopolamine-treated patients were higher at week 6 (65% vs. 20%). Dry mouth, dizziness, and blurred vision were each noted by at least 40% of scopolamine recipients.
Comment: This study shows that scopolamine given orally (a much preferable route of administration for routine clinical practice) adds significantly to the effect of a selective serotonin reuptake inhibitor for initial treatment of moderate-to-severe depression, although whether it is worth the side effect burden is unclear. Unfortunately, we also do not know whether scopolamine would benefit patients with treatment-resistant depression, although this study's effects in relatively severe depression suggest that such a trial might be pursued. The study's high rate of placebo response (but not remission) and the absence of formal cognitive testing compromise the generalizability of the findings.

Oral Scopolamine Augmentation for Major Depression

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

Генетические вариации эндоканнабиноидной системы и ответ на терапию циталопрамом

First line treatment of major depression is based on selective serotonin re-uptake inhibitors (SSRIs) that enhance serotonergic neurotransmission by blocking the serotonin transporter. However, clinical response is a complex phenomenon in which other systems such as the endocannabinoid system could be involved. Given the evidence for the role of the endocannabinoid system in the pathogenesis of depression as well as in the mediation of antidepressant drug effects, the aim of this study was to analyze genetic variability in the endocannabinoid system genes (CNR1, CNR2 and FAAH genes) and their role in clinical response (at week 4) and remission (at week 12) in SSRI (citalopram) treatment in a sample of 154 depressive outpatients, all of Spanish origin. All patients were treated with citalopram and followed over 12 weeks. Severity of depressive symptomatology was evaluated by means of the 21-item Hamilton Depression Rating Score (HDRS). No differences were found in any of the genotype distributions according to response or remission. The longitudinal study showed that (i) the CNR1 rs1049353-GG genotype conferred a better response to citalopram treatment in the subgroup of male patients and (ii) G allele carriers (CNR2 rs2501431) presented higher HDRS scores in the follow-up than AA homozygous allele carriers. Our results seem to suggest the involvement of CNR1 and CNR2 genes in clinical responses to citalopram treatment.

 Genetic variability in the endocannabinoid system and 12-week clinical response to citalopram treatment: the role of the CNR1, CNR2 and FAAH genes

Потенцирование антидепрессивного действия циталопрама пиоглитазоном

Thiazolidinediones have shown antidepressant effect in animal studies, as well as in some uncontrolled studies evaluating human subjects with concurrent major depressive disorder (MDD) and metabolic syndrome. Although these drugs are insulin sensitizers, they also have important anti-inflammatory, neuroprotective, and anti-excitotoxic properties. Thus, we hypothesized that they would show antidepressant effect in patients with MDD even if it was not accompanied by metabolic disturbances. In this double-blind placebo-controlled study, 40 patients with MDD (DSM-IV-TR) and Hamilton depression rating scale-17 (Ham-D) score 22 were randomized to citalopram plus pioglitazone (15 mg every 12 h) (n=20) or citalopram plus placebo (n=20) for 6 weeks. Patients were evaluated using Ham-D (weeks 0, 2, 4, 6). Repeated-measure analysis of variance (ANOVA) and analysis of covariance were used for comparison of scores between the two groups. Treatment response (50% reduction in Ham-D score), remission (Ham-D score7), and early improvement (20% reduction in Ham-D score within the first 2 weeks) were compared between the two groups using Fisher's exact test. Pioglitazone showed superiority over placebo during the course of the trial (F(1, 38)=9.483, p=0.004). Patients in the pioglitazone group had significantly lower scores at all time points than the placebo group (P<0.01). Frequency of early improvement, response (week 6), and remission was significantly higher in the pioglitazone group (95%, 95%, 45%, respectively) than in the placebo (30%, 40%, 15% respectively) group (P<0.001, <0.001, 0.04, respectively). Frequency of side effects was similar between the two groups. Pioglitazone is a safe and effective adjunctive short-term treatment in patients with moderate-to-severe MDD even in the absence of metabolic syndrome and diabetes.

Pioglitazone Adjunctive Therapy for Moderate-to-Severe Major Depressive Disorder: Randomized Double-Blind Placebo-Controlled Trial.

Психостимуляторы для пожилых больных

Psychostimulants are recognized for their role in managing attention-deficit/hyperactivity disorder
(ADHD), but also have found a treatment niche in conditions such as apathy, fatigue, and depression.

Psychostimulants for older adult

Фармакогенетика СИОЗС, ассоциации между полиморфизмом CYP2D6 и CYP2C19 и ответом на терапию антидепрессантом

An investigation of MEDLINE and other database resources was carried out to summarize the research conducted between 1970 and 2003 in the role of CYP2D6 genetics on SSRI dose exposure.^[2] Area-under-the-concentration curve (AUC) values of 5 SSRIs in poor metabolizers, intermediate metabolizers, and extensive metabolizers as a measure of bioavailability were collected. Dose adjustments were then calculated to compensate for variability in CYP2D6 metabolizer status in white patients. On the basis of metabolizer phenotype, the following dose adjustments were extrapolated for extensive vs poor metabolizers: 33%-129% for fluvoxamine, 66%-114% for paroxetine, 56%-119% for fluoxetine (including the AUC of its active metabolite), 98%-101% for citalopram, and 99-100% for sertraline. A dose adjustment of 130% for paroxetine was extrapolated for ultrarapid metabolizers.

However, the study authors concluded that dose adjustments that are based on CYP2D6 could not be recommended for SSRIs for various reasons. They noted the limited data from multiple dosing, which more accurately reflects the clinical situation; the unknown effect of saturation kinetics of some SSRIs (eg, paroxetine and fluvoxamine); and the long-term effect of inhibition of CYP2D6 by some SSRIs (eg, fluoxetine, fluvoxamine, and paroxetine) when given in chronic treatment regimens. Thus, basic human pharmacokinetic data do not strongly support routine clinical use of CYP2D6 testing.

Another study scanning 1200 Web-based articles between 1966 and 2006 for treatment of major depression found no consistent association between CYP2D6 genotype and SSRI metabolism, efficacy, or risk for side effects.^[3]Although 2 studies showed greater nonresponse to SSRIs among ultrarapid metabolizers relative to the general population, the data were inconsistent across other studies. The study authors concluded that there is no established association between plasma drug concentration and SSRI drug response at standard doses.

Finally, a study of SSRI drug response and tolerability in 1953 patients enrolled in the Sequenced Treatment of Alternatives to Relieve Depression (STAR*D) study also showed no significant association between CYP2D6 variants and citalopram response, remission, or tolerability when comparing extensive metabolizers with poor metabolizers. However, the study design included numerous concomitant medications with unknown confounding effects.^[4]

The complexity derived from interaction between multiple CYP enzymes was highlighted in a study of the impact of extensive and poor metabolizer status for CYP2D6 and CYP2C19 on the SSRI citalopram. Researchers showed that the AUC for citalopram correlated with the combined CYP2D6/CYP2C19 metabolizer status.^[5] For example, individuals with CYP2D6 extensive metabolizer/CYP2C19 poor metabolizer status showed significantly higher citalopram AUC compared with extensive/extensive metabolizer or poor/extensive metabolizer carriers. Because citalopram metabolism is preferentially catalyzed by CYP2C19 over CYP2D6, consideration of more than 1 genetic variant may be necessary to guide medication dosing decisions.

Pharmacogenomics of SSRIs: Clinical Implications

Влияние нестероидных противовоспалительных средств на антидепрессивное действие СИОЗС

Cytokines may be important in depression. These immunomodulators are produced by glial cells, regulate brain serotonin and noradrenergic systems, and activate the hypothalamic-pituitary-adrenal axis. Antidepressants increase levels of p11, a specific protein that regulates depression in rodent models and interacts with the serotonin receptor. To learn about possible interactions of antidepressants, cytokines, p11, and anti-inflammatory drugs (NSAIDs), researchers conducted experiments in mice and reanalyzed data from the large STAR*D study.

The selective serotonin reuptake inhibitors citalopram and fluoxetine increased p11 levels in mouse frontal cortex, but coadministered ibuprofen (IBU) or acetylsalicylic acid (ASA) blocked this increase. IBU lowered plasma citalopram levels. The tricyclic desipramine produced a small p11 increase, which was not affected by IBU or ASA. Antidepressant-related p11 increases were dependent on signaling by two cytokines (interferon-gamma and tumor necrosis factor-alpha). In a mouse model of depression, IBU, ASA, and acetaminophen prevented the behavioral response to SSRIs but not to antidepressants of other types.

Of STAR*D patients who took citalopram for 12 weeks, significantly fewer achieved remission if taking NSAIDs than if not taking NSAIDs (45% vs. 55%). Findings were similar in a comparison of other analgesic use with nonuse (37% vs. 54%).

Do Analgesics Interfere with Efficacy of Selective Serotonin Reuptake Inhibitors?

Профилактика депрессий при лечении гепатита C, неэффективность циталопрама

BACKGROUND: Approximately one-third of patients undergoing interferon-{alpha} (IFN-{alpha}) therapy for treatment of the hepatitis C virus (HCV) develop major depression, which decreases functioning and may lead to the reduction or discontinuation of treatment. OBJECTIVE: The authors examined the efficacy of citalopram in preventing IFN-{alpha}-induced depression in HCV patients. METHOD: This was a randomized, controlled trial comparing citalopram with placebo in 39 HCV patients. RESULTS: The rate of IFN-{alpha}-induced depression in the sample was 15.4% (6/39). Randomization to citalopram did not decrease the statistical likelihood of developing IFN-{alpha}-induced depression (10.5% for citalopram vs. 20.0% for placebo). CONCLUSION: Citalopram does not prevent depression onset; however, an empirically-supported treatment recommendation for IFN-{alpha}-induced depression includes monitoring depressive symptoms throughout antiviral therapy and initiating psychiatric treatment at the initial signs of depression.

Prophylactic Antidepressant Treatment in Patients With Hepatitis C on Antiviral Therapy: A Double-Blind, Placebo-Controlled Trial

STAR*D

The Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial was a longitudinal, multi-center, 5-year study of common strategies for treating depression. To date, it is the United States’ largest National Institute of Mental Health funded study including over 4,000 patients. This four level trial compared traditional augmentation strategies with switching agents (Slide 2).30-34 Unlike most depression studies, in STAR*D the outcome measure was full remission.
In Level 1, the initial monotherapy phase, citalopram (mean dose of 41.8 mg) was effective at achieving remission for only ~30% of subjects. This finding has been accepted as an accurate reflection of clinical experience with any initial monotherapy. The remaining 70% were randomized to either receive bupropion or buspirone augmentation, or switched to one of three antidepressants as monotherapy—bupropion, venlafaxine, or sertraline. Augmentation resulted in a 30% response, while switching antidepressants resulted in ~20% of patients achieving remission. Level 3 included those non-remitters from Level 2 who were then randomized to either T3 or lithium augmentation, resulting in remission rates of 25% and 16% respectively. A Level 3 switch to nortriptyline (NTP) or mirtazapine (MTZ) was in general less successful than Level 3 augmentation, with 20% of NTP patients and 12% of MTZ patients remitting. Level 4 treatment options (monoamine oxidase inhibitors [MAOIs] or venlafaxine–mirtazapine-combination therapy) were provided to patients who had not responded satisfactorily to previous levels of the treatment protocol, and very few experienced full remission (14% and 7% respectively).12,35


An overall analysis of STAR*D results indicates that the chances of achieving and maintaining remission in patients with difficult-to-treat depression diminishes with every additional strategy needed. Those who fully remit early in the course of treatment have a better chance of remaining well than those who experience only symptomatic improvement. STAR*D does not tell us which treatment works better as a first or second adjunct, simply that the greatest chance of recovery appears to lie with the first two sequential treatments.

The Role of L-methylfolate in Depressive Disorders

Резистентные к лечению депрессии

Antidepressants can be grouped into 6 major categories: tricyclic antidepressants (TCAs), SSRIs, serotonin norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), serotonin neurotransmitter (5-HT2)-receptor antagonists (eg, nefazodone, trazodone), and novel agents (eg, mirtazapine, bupropion). If a patient fails to respond to one antidepressant class, it makes sense (at least conceptually) to switch to another, although most guidelines acknowledge that 2 failed trials of SSRIs may be justifiable before switching classes.
For example, in a study by Thase and colleagues,10 58 patients failed a trial of fluoxetine; however, there was a 76% response rate to citalopram among completers. Although this study was not blinded, it is interesting that citalopram (which is believed to be the most selective of the SSRIs) was effective when another SSRI was not.
Antidepressants that are associated with discontinuation symptoms (eg, paroxetine, venlafaxine, duloxetine) may produce discontinuation syndromes when stopped that can be erroneously attributed to adverse effects of the new drug, particularly if the new drug does not possess a significant degree of serotonin reuptake inhibition.
In a study by Zarate and colleagues,21 the onset of the antidepressant effect of ketamine occurred within 2 hours. Unfortunately, the drug must be given by intravenous infusion, but because the effect persisted for 7 days, ketamine treatment may be useful if given as a series.
Another NMDA-receptor antagonist now available in the United States is memantine (FDA-approved for Alzheimer disease). Memantine was shown to be effective in an open-label study in major depression. In a double-blind, randomized trial it showed comparable effects to escitalopram in patients with major depression and alcohol dependence.
Randomized controlled trials have supported the superior efficacy of a TCA/SSRI combination, as well as a mirtazapine/SSRI combination; open studies have done the same for TCA/MAOI and SSRI/bupropion combinations.
As with lithium, a recent review concluded that the trial data that support the efficacy of T3 augmentation are of better quality with TCAs than with SSRIs

Treatment-Resistant Depression

Genetic and Clinical Predictors of Sexual Dysfunction in Citalopram-Treated Depressed Patients

These hypothesis-generating analyses suggest the potential for glutamatergic treatment targets for sexual dysfunction during major depressive episodes.

http://www.nature.com/npp/journal/v34/n7/abs/npp20094a.html