Adjunctive pregabalin in partial responders with major depressive disorder and residual anxiety

Exploring the Therapeutic Potential of Gamma-Aminobutyric Acid in Stress and Depressive Disorders through the Gut-Brain Axis

Research conducted on individuals with depression reveals that major depressive disorders (MDDs) coincide with diminished levels of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) in the brain, as well as modifications in the subunit composition of the primary receptors (GABAA receptors) responsible for mediating GABAergic inhibition. Furthermore, there is substantial evidence supporting the significant role of GABA in regulating stress within the brain, which is a pivotal vulnerability factor in mood disorders. GABA is readily available and approved as a food supplement in many countries. Although there is substantial evidence indicating that orally ingested GABA may affect GABA receptors in peripheral tissues, there is comparatively less evidence supporting its direct action within the brain. Emerging evidence highlights that oral GABA intake may exert beneficial effects on the brain and psyche through the gut-brain axis. While GABA enjoys wide consumer acceptance in Eastern Asian markets, with many consumers reporting favorable effects on stress regulation, mood, and sleep, rigorous independent research is still largely lacking. Basic research, coupled with initial clinical findings, makes GABA an intriguing neuro-nutritional compound deserving of clinical studies in individuals with depression and other psychological problems.

Using genetic drug-target networks to develop new drug hypotheses for major depressive disorder

The major depressive disorder (MDD) working group of the Psychiatric Genomics Consortium (PGC) has published a genome-wide association study (GWAS) for MDD in 130,664 cases, identifying 44 risk variants. We used these results to investigate potential drug targets and repurposing opportunities. We built easily interpretable bipartite drug-target networks integrating interactions between drugs and their targets, genome-wide association statistics, and genetically predicted expression levels in different tissues, using the online tool Drug Targetor ( drugtargetor.com ). We also investigated drug-target relationships that could be impacting MDD. MAGMA was used to perform pathway analyses and S-PrediXcan to investigate the directionality of tissue-specific expression levels in patients vs. controls. Outside the major histocompatibility complex (MHC) region, 153 protein-coding genes are significantly associated with MDD in MAGMA after multiple testing correction; among these, five are predicted to be down or upregulated in brain regions and 24 are known druggable genes. Several drug classes were significantly enriched, including monoamine reuptake inhibitors, sex hormones, antipsychotics, and antihistamines, indicating an effect on MDD and potential repurposing opportunities. These findings not only require validation in model systems and clinical examination, but also show that GWAS may become a rich source of new therapeutic hypotheses for MDD and other psychiatric disorders that need new-and better-treatment options.

Use and safety of antiepileptic drugs in psychiatric inpatients-data from the AMSP study

The psychiatric utilization patterns and risks of antiepileptic drugs (AEDs) were assessed by using data from the drug safety programme Arzneimittelsicherheit in der Psychiatrie over the time period 1993-2013. In a total of 432,215 patients, the main indications for AED use were acute mania, schizoaffective disorder, and schizophrenic and organic psychoses. Valproic acid (VPA) was the most common substance across all of those groups, reaching administration rates of up to 50% since 2005, at which time carbamazepine (CBZ) administration consistently dropped below a rate of 10%. Lamotrigine (LTG) and pregabalin (PGB) increased in relevance after 2005 and 2010, respectively (with administration rates of up to 9%), whereas oxcarbazepine (OXC) was least prevalent (<3%). The mean rates of severe adverse drug reactions (ADRs) ranged from 6 cases per 1000 patients treated (VPA) to 19/1000 (OXC) and were significantly lower with treatment with VPA compared to OXC and CBZ. Hyponatremia was the leading ADR during treatment with OXC; severe allergic skin reactions were most often observed during treatment with CBZ and LTG, and severe oedema was most common during treatment with PGB. Severe hyponatremia induced by OXC was observed significantly more often in female patients than in male patients.

Pregabalin for the treatment of patients with generalized anxiety disorder with inadequate treatment response to antidepressants and severe depressive symptoms

To evaluate the effectiveness of pregabalin in patients with resistant generalized anxiety disorder (GAD) and severe depressive symptoms, we carried out a post-hoc analysis of a multicenter, prospective, and observational 6-month study. We included patients who were at least 18 years old, fulfilled the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria for GAD, showed inadequate responses to previous courses of antidepressant treatment, had Montgomery-Asberg Rating Scale scores of at least 35, had not received pregabalin previously, and were prescribed pregabalin upon entry into this study. We included 1815 patients fulfilling the DSM-IV criteria for GAD, and 133 (7.3%) fulfilled the selection criteria for these analyses. Ninety-seven percent of the patients received pregabalin (mean dose: 222 mg/day) in combination with other psychotropics. The Hamilton Anxiety Scale total score was reduced by a mean of 20.3 points (95% confidence interval, 22.1-18.4) (57.2% reduction) at month 6. Pregabalin also ameliorated comorbid depressive symptoms, with a reduction in the mean score of the Montgomery-Asberg Rating Scale of 22.3 points (95% confidence interval, 24.2-20.4) (56.6% reduction). Our results suggest that pregabalin, as part of a combination regimen with antidepressants and/or benzodiazepines, might be effective for the treatment of patients with GAD who have shown inadequate response to previous antidepressants and have severe depressive symptoms.

Pharmacokinetic and pharmacodynamic interactions between antiepileptics and antidepressants

INTRODUCTION

Antiepileptic-antidepressant combinations are frequently used by clinicians; their pharmacokinetic (PK) and pharmacodynamic (PD) drug interactions (DIs) have not been well studied but are frequently likely to be clinically relevant.

AREAS COVERED

This article provides a comprehensive review of PK DIs between antiepileptics and antidepressants. In the absence of PD DI studies, PD information on pharmacological mechanisms and studies on efficacy and safety of individual drugs are reviewed.

EXPERT OPINION

The clinical relevance of the inductive properties of carbamazepine, phenytoin, phenobarbital and primidone and the inhibitory properties of valproic acid and some antidepressants are well understood; correction factors are provided if appropriate DI studies have been completed. More PK studies are needed for: i) antiepileptics with potent inductive effects for all recently approved antidepressants; ii) high doses of mild CYP3A4 inducers, such as clobazam, eslicarbazepine, oxcarbazepine, rufinamide and topiramate for reboxetine and vilazodone; iii) valproate as a possible inhibitor, mild inducer or both a mild inducer and competitive inhibitor of some antidepressants; and iv) inhibitory effects of long-term fluoxetine use on clobazam, lacosamide, phenobarbital, primidone, carbamazepine, felbamate, tiagabine and zonisamide. Possible synergistic or additive beneficial PD DIs in generalized anxiety disorder, chronic pain, migraine prophylaxis, weight control and menopausal symptoms need study.

Pregabalin-induced self-harm behavior

Antiepileptic Drugs (AEDs) such as lamotrigine, gabapentin, and oxcarbazepine may have the potential to increase the risk of self-harm or suicidal behavior. We report a case of pregabalin-induced self-inflicted multiple injuries on forearm after its continuous use. This is an interesting adverse drug reaction (ADR) that is rare, unusual, and potentially serious.

Pregabalin in acute treatment of anxious depression: a case series

Symptoms of anxiety are common in patients with depression. In this retrospective case series we investigated the effect of Pregabalin as an add-on medication in unipolar depressed patients with high levels of anxiety. The therapeutic effect of Pregabalin showed a fast onset and was comparable to the anxiolytic effect of benzodiazepines.