Pregabalin for generalized anxiety disorder: an updated systematic review and meta-analysis

GABAergic implications in anxiety and related disorders

Evidence indicates that anxiety disorders arise from an imbalance in the functioning of brain circuits that govern the modulation of emotional responses to possibly threatening stimuli. The circuits under consideration in this context include the amygdala's bottom-up activity, which signifies the existence of stimuli that may be seen as dangerous. Moreover, these circuits encompass top-down regulatory processes that originate in the prefrontal cortex, facilitating the communication of the emotional significance associated with the inputs. Diverse databases (e.g., Pubmed, ScienceDirect, Web of Science, Google Scholar) were searched for literature using a combination of different terms e.g., "anxiety", "stress", "neuroanatomy", and "neural circuits", etc. A decrease in GABAergic activity is present in both anxiety disorders and severe depression. Research on cerebral functional imaging in depressive individuals has shown reduced levels of GABA within the cortical regions. Additionally, animal studies demonstrated that a reduction in the expression of GABAA/B receptors results in a behavioral pattern resembling anxiety. The amygdala consists of inhibitory networks composed of GABAergic interneurons, responsible for modulating anxiety responses in both normal and pathological conditions. The GABAA receptor has allosteric sites (e.g., α/γ, γ/β, and α/β) which enable regulation of neuronal inhibition in the amygdala. These sites serve as molecular targets for anxiolytic medications such as benzodiazepine and barbiturates. Alterations in the levels of naturally occurring regulators of these allosteric sites, along with alterations to the composition of the GABAA receptor subunits, could potentially act as mechanisms via which the extent of neuronal inhibition is diminished in pathological anxiety disorders.

Genome-wide study of half a million individuals with major depression identifies 697 independent associations, infers causal neuronal subtypes and biological targets for novel pharmacotherapies

In a genome-wide association study (GWAS) of 685,808 individuals with major depression (MD) and 4,364,225 controls from 29 countries and across diverse and admixed ancestries, we identify 697 independent associations at 636 genetic loci, 293 of which are novel. Using fine-mapping and functional genomic datasets, we find 308 high-confidence gene associations and enrichment of postsynaptic density and receptor clustering. Leveraging new single-cell gene expression data, we conducted a causal neural cell type enrichment analysis that implicated excitatory and inhibitory midbrain and forebrain neurons, peptidergic neurons, and medium spiny neurons in MD. Critically, our findings are enriched for the targets of antidepressants and provide potential antidepressant repurposing opportunities (e.g., pregabalin and modafinil). Polygenic scores (PGS) from European ancestries explained up to 5.7% of the variance in liability to MD in European samples and PGS trained using either European or multi-ancestry data significantly predicted case control status across all four diverse ancestries. These findings represent a major advance in our understanding of MD across global populations. We provide evidence that MD GWAS reveals known and novel biological targets that may be used to target and develop pharmacotherapies addressing the considerable unmet need for effective treatment.

Evaluation of the effects of pregabalin and dexamethasone coadministration on preemptive multimodal analgesia and anxiety in third molar surgeries: a triple-blind randomized clinical trial

OBJECTIVE

To evaluate the efficacy of pregabalin and dexamethasone coadministration in preemptive analgesia and anxiety control in lower third molar surgery.

MATERIALS AND METHODS

A triple-blind, split-mouth clinical trial conducted with patients divided into two groups: control group, receiving placebo and dexamethasone, and test group, receiving pregabalin and dexamethasone preoperatively. The evaluated variables were pain, measured by the Visual Analog Scale (VAS), anxiety assessed through the State-Trait Anxiety Inventory (STAI) questionnaires, hemodynamic parameters [Blood Pressure (BP), Heart Rate (HR), Oxygen Saturation (SpO2)], and sedation assessed by the Ramsay scale.

RESULTS

A total of 31 patients were included. The test group exhibited a significant reduction in pain at 2,4,6,8,12,16,24, and 48 h after surgery and in the consumption of rescue analgesics. Anxiety, evaluated by STAI and VAS, showed a significant decrease in the test group (p < 0.001). Additionally, there was a significant decrease in BP at most of the assessed time points (p < 0.05) and a significant reduction in HR at two different time intervals (p = 0.003 and p = 0.009), indicating a positive effect in the test group. There was no significant difference in SpO2 between the groups. Sedation assessment revealed a significant difference at all time points favoring the test group (p < 0.05). There were no significant postoperative adverse effects.

CONCLUSIONS

Pregabalin coadministered with dexamethasone demonstrated significant efficacy in controlling postoperative pain and anxiety, as well as a sedative effect.

CLINICAL RELEVANCE

The coadministration of pregabalin with dexamethasone may presents potential advantages in both pain modulation and psychological well-being of individuals undergoing third molar surgeries.

TRIAL REGISTRATION

Brazilian Clinical Trials Registry (REBEC), No. RBR-378h6t6.

Prescription opioid use among people with opioid dependence and concurrent benzodiazepine and gabapentinoid exposure: An analysis of overdose and all-cause mortality

BACKGROUND

Studies investigating mortality risk associated with use of opioid analgesics, benzodiazepines, gabapentinoids, and opioid agonist treatment (OAT) among people with opioid dependence (PWOD) are lacking. This study addresses this gap using a cohort of 37,994 PWOD initiating opioid analgesics between July 2003 and July 2018 in New South Wales, Australia.

METHODS

Linked administrative records provided data on dispensings, sociodemographics, clinical characteristics, OAT, and mortality. Cox proportional hazards models assessed associations between time-varying measures of individual and concurrent medicine use and OAT with all-cause mortality, accidental opioid overdose, non-drug induced accidents, and non-drug-induced suicide. Opioid analgesic dose effects, expressed as oral morphine equivalents (OMEs) per day, were also examined.

OUTCOMES

During the study period, 3167 individuals died. Compared with no use, all medicines of interest were associated with increased accidental opioid overdose risk; hazard ratios (HR) ranged from 1.33 (95 % CI: 1.05-1.68) for opioid analgesic use to 6.10 (95 % CI: 4.11-9.06) for opioid analgesic, benzodiazepine and gabapentinoid use. Benzodiazepine use was associated with increased non-drug-induced accidents and non-drug-induced suicides. For all-cause mortality, all combinations of benzodiazepines and gabapentinoids with opioid analgesics were associated with increased risk (aHRs ranged from 1.35 to 2.73). For most medicines/medicine combinations, all-cause mortality risk was reduced when in OAT compared to out of OAT. Higher opioid analgesic doses were associated with increased all-cause mortality (e.g., 90-199 mg vs 1-49 mg OME per day: HR 1.90 [95 % CI: 1.52-2.40]).

INTERPRETATION

The increased mortality risk associated with benzodiazepines and gabapentinoids among PWOD appear to be reduced when engaged in OAT. A greater focus on encouraging OAT engagement, providing overdose prevention education, and access and coverage of overdose antidotes is necessary to minimise the unintended consequences of medicines use in this population.

[Anxiety and substance abuse disorders-Focus on alcohol and cannabis]

Anxiety disorders are frequent, with a 12-month prevalence of 14%, tend to be chronic, and display a high comorbidity with substance abuse disorders. Anxiety and substance abuse disorders are associated with a pronounced individual as well as socioeconomic burden. This article reviews the epidemiological, etiological, and clinical aspects of the dual diagnosis of anxiety and substance abuse disorders, with a particular focus on alcohol and cannabis. The treatment comprises nonpharmacological strategies, mainly cognitive behavioral therapy combined with elements of motivational interviewing (MI) and pharmacological management with antidepressants; however, the use of selective serotonin reuptake inhibitors (SSRI)/serotonin and noradrenaline reuptake inhibitors (SNRI) is not unreservedly recommended. The use of gabapentinoids requires careful risk-benefit consideration because of their potential for abuse and dependence in substance abuse disorders. Benzodiazepines are reserved exclusively for crisis management. Rapid diagnosis and treatment initiation targeting both disorders are essential for successful treatment of comorbid anxiety and substance abuse disorders.

Long-term benzodiazepine prescription in treatment-resistant depression: A national FACE-TRD prospective study

BACKGROUND

Benzodiazepine long-term use (BLTU) is a public health challenge. We lack data on the consequences of LBTU on the trajectory of treatment-resistant depression (TRD).

OBJECTIVE

To determine the prevalence of BLTU in a nationwide non-selected population of patients with TRD, to determine the rate of patients succeeding at withdrawing benzodiazepines at one year and to determine if persistent BLTU is associated with poorer mental health outcomes.

METHOD

The FACE-TRD cohort is a national cohort of TRD patients recruited in 13 resistant depression expert centers between 2014 and 2021 and followed-up at one year. A standardized one-day long comprehensive battery was carried out, including trained-clinician and patient-reported outcomes, and patients were reevaluated at one year.

RESULTS

At baseline, 45.2% of the patients were classified in the BLTU group. In multivariate analysis, compared to patients without BLTU, patients with BLTU were more frequently classified in the "low physical activity" group (adjusted odds ratio (aOR) = 1.885, p = 0.036), and had higher primary healthcare consumption (B = 0.158, p = 0.031) independently of age, sex and antipsychotic consumption. We found no significant difference for personality traits, suicidal ideation, impulsivity, childhood trauma exposure, earlier age at first major depressive episode, anxiety and sleep disorders (all p > 0.05). Despite recommendations for withdrawal, <5% of BLTU patients withdraw benzodiazepines during the one-year follow-up. Persistent BLTU at one-year was associated with higher depression severity (B = 0.189, p = 0.029), higher clinical global severity (B = 0.210, p = 0.016), higher state-anxiety (B = 0.266, p = 0.003), impaired sleep quality (B = 0.249, p = 0.008), increased peripheral inflammation (B = 0.241, p = 0.027), lower functioning level (B = -0.240, p = 0.006), decreased processing speed (B = -0.195, p = 0.020) and verbal episodic memory (B = -0.178, p = 0.048), higher absenteeism and productivity loss (B = 0.595, p = 0.016) and lower subjective global health status (B = -0.198, p = 0.028).

CONCLUSION

Benzodiazepines are over-prescribed in TRD (in almost a half of the patients). Despite recommendations for withdrawal and psychiatric follow-up, <5% of patients successfully stopped taking benzodiazepines at one-year. Maintaining BLTU may contribute to the worsening of clinical and cognitive symptoms and of daily functioning in TRD patients. Progressive and planed withdrawal of benzodiazepines seems therefore strongly recommended in TRD patients with BLTU. Pharmacological and non-pharmacological alternatives should be promoted when possible.

Gabapentinoid Prescribing Practices at a Large Academic Medical Center

Objective

To evaluate indications for gabapentinoid prescription at an academic medical center.

Patients and Methods

We retrospectively reviewed patients aged 18 years or older who were prescribed gabapentinoids (gabapentin or pregabalin) during the 2019 calendar year at an academic medical center in the US Midwest. Patient demographic characteristics, indications for gabapentinoid prescription, and prescribing clinician specialities were abstracted from a random sample, and the findings were extrapolated to the overall cohort.

Results

A total of 6205 prescriptions for gabapentinoids were initially identified. In the random sample of prescriptions (n=721), 89.5% were for gabapentin and 10.5% were for pregabalin. More women than men were prescribed gabapentinoids, and the mean ± SD patient age was 58.6±16.9 years. The top 5 indications for gabapentinoid prescriptions were neuropathic pain, musculoskeletal pain, restless legs syndrome, anxiety, and headache. A majority (66.7%) of prescriptions had substantial-to-modest evidence, but 29.0% of prescriptions had conflicting or insufficient evidence.

Conclusion

To our knowledge, this study is one of the first to manually review clinical notes from multiple clinical specialities to ascertain indications for gabapentinoid prescriptions. Although most prescriptions had modest evidence to support their use, a high percentage of gabapentinoid prescriptions were issued for indications not supported by robust evidence. This suggests that prescribers are gravitating toward gabapentinoid use for reasons that are currently not fully understood. Clinician intent for off-label gabapentinoid prescriptions at the point of care should be further studied to understand the factors that lead to these clinical decisions.

Randomized clinical trial: the effects of pregabalin for centrally mediated abdominal pain syndrome

Background

Pregabalin is worldwidely licensed for the treatment of a variety of pain syndromes and supposed to be a potential candidate for the centrally mediated abdominal pain syndrome (CAPS).

Objectives

To investigate the efficacy of pregabalin on nociceptive and emotional symptoms in CAPS patients.

Design

This is an open-label randomized controlled trial.

Methods

CAPS patients were randomized to receive pregabalin 75 mg (P group), pinaverium bromide 50 mg (PB group), or pregabalin combined pinaverium bromide regimen (P + PB group) three times daily for 4 weeks. Questionnaires were completed biweekly. The primary outcomes were defined as the average abdominal pain scores of severity and frequency at weeks 2 and 4. Secondary outcomes included the reduction in abdominal pain scores, Somatic Self-rating Scale (SSS), Patient Health Questionnaire-15 (PHQ-15), and Generalized Anxiety Disorder Scale 7 (GAD-7) scales obtained at the end of trial to the baseline.

Results

Totally, 102 eligible patients were recruited and randomized. The mean severity scores of abdominal pain were 1.39 ± 1.28, 0.97 ± 1.43 versus 2.91 ± 1.44 (p < 0.0001) in P or PB + P group versus PB group at week 2 and were 0.90 ± 1.21, 1.28 ± 1.87 versus 2.74 ± 1.75 (p < 0.0001) at week 4. The mean frequency scores were 2.55 ± 2.55, 2.03 ± 2.80 versus 5.12 ± 2.09(p < 0.0001) in P or PB + P group versus PB group at week 2 and were 1.72 ± 2.46, 2.00 ± 2.90 versus 4.55 ± 2.55 (p < 0.0001) at week 4. When comparing the changes in SSS, PHQ-15, and GAD-7 scores, patients accepting pregabalin or pregabalin combination regimen reported a more decrease than pinaverium bromide recipients (p = 0.0002, p = 0.0002, and p = 0.0033).

Conclusion

This trial suggests that pregabalin may be beneficial for CAPS abdominal pain and concomitant somatic or anxiety symptoms.

Registration

www.chictr.org.cn (ChiCTR1900028026).

Ketamine Treatment for Refractory Anxiety: A systematic review

There is a growing interest in the psychiatric properties of the dissociative anaesthetic ketamine, as single doses have been shown to have fast‐acting mood‐enhancing and anxiolytic effects, which persist for up to a week after the main psychoactive symptoms have diminished. Therefore, ketamine poses potential beneficial effects in patients with refractory anxiety disorders, where other conventional anxiolytics have been ineffective. Ketamine is a noncompetitive antagonist of the N‐methyl‐d‐aspartate (NMDA) glutamate receptor, which underlies its induction of pain relief and anaesthesia. However, the role of NMDA receptors in anxiety reduction is still relatively unknown. To fill this paucity in the literature, this systematic review assesses the evidence that ketamine significantly reduces refractory anxiety and discusses to what extent this may be mediated by NMDA receptor antagonism and other receptors. We highlight the temporary nature of the anxiolytic effects and discuss the high discrepancy among the study designs regarding many fundamental factors such as administration routes, complementary treatments and other treatments.

Association Between Mild Neurocognitive Disorder Due to Alzheimer's Disease and Possible Attention-deficit/Hyperactivity Disorder: A Case Report

Recent literature concerning attention-deficit/hyperactivity disorder (ADHD) underlines the persistence of this neurodevelopmental illness in older patients. Comorbidity with a neurodegenerative disease is thus possible. However, few studies have investigated this topic. To our knowledge, this is the first case report of such a possible association, which raises important questions about clinical presentation, symptoms, diagnosis, and treatment. A 72-year-old man, without any psychiatric history, presented with depression, subjective memory loss, and attention deficit and anxious symptoms, and was diagnosed with mild neurocognitive disorder due to Alzheimer's disease. However, the patient's attentional symptoms appeared to have been present since childhood. A formalized diagnostic interview assessing for ADHD did not allow for a clear diagnosis, possibly due to recall bias. The patient's anxiety symptoms also did not respond well to cognitive behavioral therapy coupled with different antidepressants. We hypothesized the presence of ADHD, with the symptoms balanced until now by the patient's high cognitive capacities, and we postulated that the onset of a neurogenerative process may have disrupted this balance. In this case report, we discuss symptom dimensionality, the interplay between neurodegenerative and neurodevelopmental diseases, and various treatment options. Attentional deficits and anxiety symptoms are frequent in mild neurocognitive disorders due to neurodegenerative illnesses. It is important to explore the time of onset of such symptoms since neurodegenerative processes can worsen neurodevelopmental conditions. Moreover, identification of a pre-existing neurodevelopmental condition can lead to alternative care and treatment options. In addition, the unexplained worsening of ADHD symptoms should prompt clinicians to assess for a neurodegenerative process.

Clinical management of withdrawal from benzodiazepine anxiolytic and hypnotic medications

Benzodiazepines continue to be prescribed widely in the management of patients with insomnia or anxiety disorders, despite the availability and acceptability of alternative pharmacological and psychological treatments. Many patients will experience adverse effects during treatment and considerable distress when the dosage is reduced and stopped. Management of benzodiazepine withdrawal includes measures to prevent the development of dependence, careful attention to underlying medical conditions, medication consolidation and gradual dosage reduction, accompanying psychological interventions, occasional prescription of concomitant medication, and relapse prevention with on-going support to address psychosocial stressors. There are needs for easier patient access to services with refined expertise and for further research to optimise strategies for preventing dependence and facilitating withdrawal.

A Review of Ocular Complications Associated with Medications Used for Anxiety, Depression, and Stress

This review of commonly prescribed psychotropic drugs aims to update the clinician on possible ophthalmic side effects that may include dry eye, diplopia, mydriasis, and cataracts. This review summarizes our current knowledge of known ocular side effects of psychotropic drugs based on reviews, case reports, case-control studies, a case series, and cross-sectional observational studies reported in the recent literature. The review covers disorders related to depression, anxiety, and stress which are commonly encountered within society and can have debilitating impacts on an individual's quality of life that may require chronic therapeutic management. The main medications used in the treatment and management of these conditions typically target receptors, metabolic enzymes, or transport pumps that alter the pre- and/or post-synaptic levels of neurotransmitters such as serotonin, norepinephrine, dopamine, gamma-aminobutyric acid, and opioids to improve mood and/or relieve pain and anxiety. Novel non-therapeutic options are undergoing clinical trials, and some patients may seek alternative therapies or have associated substance abuse issues to alleviate their symptoms. This review summarizes some of the clinical signs of depression and the main therapeutic options and their reported ocular side effects which may be pertinent today given the rise in use of psychotropic medications used to manage depression, anxiety, and stress.

Early Optimized Pharmacological Treatment in Patients With Depression and Chronic Pain

Major depressive disorder (MDD) is the leading cause of disability worldwide. Patients with MDD have high rates of comorbidity with mental and physical conditions, one of which is chronic pain. Chronic pain conditions themselves are also associated with significant disability, and the large number of patients with MDD who have chronic pain drives high levels of disability and compounds healthcare burden. The management of depression in patients who also have chronic pain can be particularly challenging due to underlying mechanisms that are common to both conditions, and because many patients with these conditions are already taking multiple medications. For these reasons, healthcare providers may be reluctant to treat such patients. The Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines provide evidence-based recommendations for the management of MDD and comorbid psychiatric and medical conditions such as anxiety, substance use disorder, and cardiovascular disease; however, comorbid chronic pain is not addressed. In this article, we provide an overview of the pathophysiological and clinical overlap between depression and chronic pain and review evidence-based pharmacological recommendations in current treatment guidelines for MDD and for chronic pain. Based on clinical experience with MDD patients with comorbid pain, we recommend rapidly and aggressively treating depression according to CANMAT treatment guidelines, using antidepressant medications with analgesic properties, while addressing pain with first-line pharmacotherapy as treatment for depression is optimized. We review options for treating pain symptoms that remain after response to antidepressant treatment is achieved.

Pregabalin vs placebo to prevent chronic pain after whiplash injury in at-risk individuals: results of a feasibility study for a large randomised controlled trial

ABSTRACT

There are few effective treatments for acute whiplash-associated disorders (WADs). Early features of central sensitisation predict poor recovery. The effect of pregabalin on central sensitisation might prevent chronic pain after acute whiplash injury. This double blind, placebo-controlled randomised controlled trial examined feasibility and potential effectiveness of pregabalin compared with placebo for people with acute WAD. Twenty-four participants with acute WAD (<48 hours) and at risk of poor recovery (pain ≥5/10) were recruited from hospital emergency departments in Queensland, Australia, and randomly assigned by concealed allocation to either pregabalin (n = 10) or placebo (n = 14). Pregabalin was commenced at 75 mg bd, titrated to 300 mg bd for 4 weeks, and then weaned over 1 week. Participants were assessed at 5 weeks and 3, 6, and 12 months. Feasibility issues included recruitment difficulties and greater attrition in the placebo group. For the primary clinical outcome of neck pain intensity, attrition at 5 weeks was pregabalin: 10% and placebo: 36% and at 12 months was pregabalin: 10% and placebo: 43%. Pregabalin may be more effective than placebo for the primary clinical outcome of neck pain intensity at 3 months (mean difference: -4.0 [95% confidence interval -6.2 to -1.7]) on an 11-point Numerical Rating Scale. Effects were maintained at 6 months but not 12 months. There were no serious adverse events. Minor adverse events were more common in the pregabalin group. A definitive large randomised controlled trial of pregabalin for acute whiplash injury is warranted. Feasibility issues would need to be addressed with modifications to the protocol.

Anxiety Presentations and Treatments in Populations With Kidney Disease

Anxiety is common in patients with chronic kidney disease, but in its extreme expressions, anxiety can also be a complicating comorbid psychiatric illness. There is only a small literature base on anxiety disorders in patients with renal disease, and many of the studies are not sufficiently specific about which anxiety disorders are being studied. Larger epidemiological studies are required to delineate the incidence, prevalence, and outcomes associated with the varied anxiety disorders. In addition, the impact of the co-occurrence of anxiety with other chronic psychiatric or medical problems, needs further study. Anxiety is a clinical condition that warrants treatment, primarily due to its association with mortality in end-stage renal disease patients, and its negative impact on perceived quality of life. Therapeutic options for patients with anxiety and kidney disease include both pharmacologic and nonpharmacologic approaches. Current treatment strategies for anxiety specific to patients with renal disease are provided.

Managing the misuse potential and risk of psychological harm from gabapentinoids in primary care in New Zealand

Gabapentinoid prescribing is increasing in New Zealand. International evidence suggests that this prescribing trend is followed by increasing harms, including misuse, dependence, overdose, and psychological harms including suicidal thoughts or behaviours. However, there is limited guidance for prescribers on how to manage these potential harms. Here, we summarise the current international literature and identify three main risk factors that can be used for screening purposes when considering prescribing a gabapentinoid, to identify patients that may be at greater risk of harm. Based on current knowledge of harms, we provide guidance to prescribers on monitoring patients taking gabapentinoids. Finally, we summarise the evidence regarding tapering, and highlight key knowledge gaps including other interventions, referral, and data from primary care populations.

A Retrospective Analysis of Gabapentinoid and Opioids to Opioid Monotherapy for Pain Relief in Patients with Chronic Neck and Low Back Pain

OBJECTIVE

We compared the reduction in pain and opioid consumption in patients with chronic spinal pain on concomitant gabapentinoids and opioids with patients using opioids only.

DESIGN

This was a retrospective chart review of patients with chronic neck or low back pain who were on opioids with at least a 24-month follow-up.

SETTING

Single-center pain clinic in an urban setting.

SUBJECTS

167 patients with chronic spinal pain lasting at least six months.

METHODS

Patients on gabapentin or pregabalin were included in the gabapentinoid group, while the other patients were included in the non-gabapentinoid group. Primary outcome was assessment of pain scores measured via a numeric rating scale (NRS), and secondary outcomes were response to the treatment (>2 point reduction on NRS) and daily opioid use measured in morphine milliequivalents.

RESULTS

Pain scores were reduced in the first six months and plateaued after that in both groups. At the end of 24 months, the average pain score was 6.71 in the gabapentinoid group, while the average pain score was 7.18 in the non-gabapentinoid group. There was no statistical significance between the groups (p = 0.28). There was no difference in response to treatment in gabapentinoid group (33.3%) when compared with non-gabapentinoid group (32.7%). We also failed to find any significant difference in daily opioid usage between the two groups.

CONCLUSION

Gabapentinoids may not lead to reduction in pain or opioid consumption in patients with chronic spinal pain. A careful approach must be adopted while prescribing gabapentinoids in the chronic spinal pain patient population.

Pregabalin poisoning: Evaluation of dose-toxicity relationship

Context

Pregabalin poisoning is mostly benign, although coma and convulsions occasionally occur.

Aim

To determine the dose‐toxicity relationship of pregabalin.

Methods

Dose‐toxicity data of isolated pregabalin poisonings were collected from (1) a prospective study performed by the Dutch Poisons Information Centre (4 April 2014 to 4 October 2016) and from (2) case reports and case series reported in literature. Poisonings were graded using the Poisoning Severity Score (PSS) and the relationship between dose (mg kg⁻¹) and PSS was evaluated.

Results

In our study (n = 21 patients), the most commonly observed symptoms were drowsiness (62%), confusion (29%) and apathy (24%). PSS was none in three (14%), minor in 15 (71%), and moderate in three patients (14%). Most case series also reported a PSS of none to minor in the majority of poisonings (69‐100%). For 34 individual patients (21 from our study and 13 from literature), detailed data on dose and clinical course were available to examine the dose‐toxicity relationship.

The median dose was significantly lower in the PSS none‐minor group (“benign”) (8.6 mg kg⁻¹, interquartile range (IQ25‐75) 5.0‐17.6 mg kg⁻¹) than in the PSS moderate‐severe group (“significant toxicity”) (46.7 mg kg⁻¹, IQ25‐75 21.3‐64.3 mg kg⁻¹); estimate of the median difference = 27.3 mg kg⁻¹ (95% confidence interval (CI): 10‐48.6).

Conclusions

In general, higher pregabalin doses result in more severe poisonings. Below 20 mg kg⁻¹ the majority of patients (83%) only suffer from mild poisoning. However, large interindividual differences exist in pregabalin‐induced toxicity. Therefore, pre‐hospital triage should not only include pregabalin dose, but also underlying illnesses, co‐exposures and reported symptoms.

Evidence-Based Pharmacotherapy of Generalised Anxiety Disorder: Focus on Agomelatine

Recent network meta-analyses support the use of pharmacotherapy in patients with generalised anxiety disorder (GAD). Compared with placebo, drug treatment can improve symptoms and quality of life, and is more effective in preventing relapse. Selective serotonin reuptake inhibitors and serotonin–norepinephrine reuptake inhibitors are generally considered the first-line agents of choice in GAD, but in some patients, an alternative evidence-based treatment with a different mechanism of action may also be considered (e.g. those with severe GAD, inadequate response, adverse effects and/or contraindications). One example is agomelatine, a melatonin receptor agonist and serotonin 2C (5-HT_2C) receptor antagonist, which has been shown to have efficacy that is greater than placebo in patients with GAD, and to have a tolerability profile that compares favourably with that of escitalopram. Both agomelatine and escitalopram are efficacious in treating patients with GAD, including those with severe symptoms.

A novel index to assess low energy fracture risks in patients prescribed antiepileptic drugs

Objective

To develop an index assessing the risks of low energy fractures (LEF) in patients prescribed antiepileptic drugs (AED) by exploring five previously suggested risk factors; age, gender, AED-type, epilepsy diagnosis and BMI.

Methods

In a population-based retrospective open cohort study we used real world data from the Electronic Health Register (EHR) in Region Kalmar County, Sweden. 23 209 patients prescribed AEDs at any time from January 2008 to November 2018 and 23 281 matching controls were followed from first registration in the EHR until the first documented LEF, disenrollment (or death) or until the end of the study period, whichever came first. Risks of LEF measured as hazard rate ratios in relation to the suggested risk factors and in comparison to matched controls were analyzed using Cox regression. The index was developed using a linear combination of the statistically significant variables multiplied by the corresponding regression coefficients.

Results

Data from 23 209 patients prescribed AEDs and 2084 documented LEFs during a follow-up time of more than 10 years resulted in the Kalmar Epilepsy Fracture Risk Index (KEFRI). KEFRI = Age-category x (1.18) + Gender x (-0.51) + AED-type x (0.29) + Epilepsy diagnosis-category x (0.31) + BMI-category x (-0.35). All five previously suggested risk factors were confirmed. Women aged 75 years and older treated with an inducing AED against epilepsy and BMIs of 25 kg/m² or below had 48 times higher LEF rates compared to men aged 50 years or younger, treated with a non-inducing AED for a condition other than epilepsy and BMIs above 25 kg/m².

Conclusion

The KEFRI is the first weighted multifactorial assessment tool estimating risks of LEF in patients prescribed AEDs and could serve as a feasible guide within clinical practice.

Pregabalin withdrawal in patients without psychiatric disorders taking a regular dose of pregabalin: A case series and literature review

Pregabalin is a drug that can cause psychiatric symptoms via pregabalin withdrawal. Prior reports on pregabalin withdrawal have mainly focused on cases with pregabalin dependence or abuse, and little attention has been paid to patients who are prescribed regular doses of pregabalin. Herein, we report three cases of pregabalin withdrawal in patients without psychiatric disorders, taking regular doses of pregabalin, who developed psychiatric symptoms such as insomnia and anxiety after abrupt discontinuation of pregabalin. In addition, we conducted a systematic review of six case reports (previous studies) of pregabalin withdrawal under regular doses of pregabalin. Among the six cases, three patients had no comorbid mental or substance use disorders, the dose of pregabalin ranged from 150 to 600 mg/d, and the duration of pregabalin use ranged from a few weeks to many years. Of these six cases of pregabalin withdrawal, five had psychopathological symptoms, three had vegetative symptoms, and three had neurologic and physical complications. We concluded that since pregabalin withdrawal can occur even with regular doses and short‐term use, clinicians must carefully reduce pregabalin doses when reducing or discontinuing treatment, paying close attention to withdrawal symptoms. Our case series sheds light on the scant evidence from previous research on physical dependence in patients who are taking regular doses of pregabalin. Furthermore, our cases were also valuable in demonstrating that pregabalin withdrawal can occur even after a relatively short period of 2 months.

This case series shows pregabalin withdrawal in patients without psychiatric disorders taking a regular dose of pregabalin. Our cases demonstrated that pregabalin withdrawal can occur even after a relatively short period of 2 months following regular doses of pregabalin.

Pharmacotherapy for Anxiety Disorders: From First-Line Options to Treatment Resistance

In this review, the author examines the evidence for psychopharmacologic treatments among adults for generalized anxiety disorder, panic disorder, and social anxiety disorder derived from clinical trials. For each disorder, major categories of drugs are reviewed, and then the evidence-based medications in each category are discussed. The author reviews key safety and tolerability considerations for each of the medications or classes. Evidence-based dosing for most specific agents is displayed in a comprehensive reference table. Subsequently, the author synthesizes the available information to suggest a pragmatic stepwise approach to treatment that accounts for patient-specific factors. To inform the guidance, the author incorporates and refines perspectives from treatment guidelines already written by clinical professional organizations. The author also briefly reviews the relatively new quantitative systematic review methodology of network meta-analysis (NMA) and discusses how NMA may help guide pharmacologic treatment sequencing decisions in the future by way of ranking treatments according to effect size and the relative amount of study to which treatments have been subject. Caveats of NMA studies are briefly discussed, as are results of recent NMAs regarding the pharmacologic treatment of anxiety disorders.

Pharmacotherapy of Anxiety Disorders: Current and Emerging Treatment Options

(Appeared originally in Frontiers in Psychiatry 2020 Dec 23; 11:595584)

Anxiety disorders

Anxiety disorders form the most common group of mental disorders and generally start before or in early adulthood. Core features include excessive fear and anxiety or avoidance of perceived threats that are persistent and impairing. Anxiety disorders involve dysfunction in brain circuits that respond to danger. Risk for anxiety disorders is influenced by genetic factors, environmental factors, and their epigenetic relations. Anxiety disorders are often comorbid with one another and with other mental disorders, especially depression, as well as with somatic disorders. Such comorbidity generally signifies more severe symptoms, greater clinical burden, and greater treatment difficulty. Reducing the large burden of disease from anxiety disorders in individuals and worldwide can be best achieved by timely, accurate disease detection and adequate treatment administration, scaling up of treatments when needed. Evidence-based psychotherapy (particularly cognitive behavioural therapy) and psychoactive medications (particularly serotonergic compounds) are both effective, facilitating patients' choices in therapeutic decisions. Although promising, no enduring preventive measures are available, and, along with frequent therapy resistance, clinical needs remain unaddressed. Ongoing research efforts tackle these problems, and future efforts should seek individualised, more effective approaches for treatment with precision medicine.

Efficacy of Agomelatine 25-50 mg for the Treatment of Anxious Symptoms and Functional Impairment in Generalized Anxiety Disorder: A Meta-Analysis of Three Placebo-Controlled Studies

Introduction

The purpose of this study is to investigate the effects of agomelatine on anxious symptoms and functional impairment in a pooled dataset from randomized placebo-controlled trials for generalized anxiety disorder (GAD).

Methods

Data from three randomized, placebo-controlled trials that evaluated the efficacy of agomelatine 25–50 mg were pooled. The short-term (12 weeks) efficacy of agomelatine was assessed in regards to (1) anxious symptoms using the Hamilton Anxiety Scale (HAM-A), and (2) functional impairment using the Sheehan Disability Scale (SDS). Meta-analysis using a random effect model was used to assess differences between groups. Remission and response rates for the HAM-A and SDS were calculated, and analyses were repeated in participants with more severe anxiety symptoms.

Results

In total, 669 patients (340 on agomelatine; 329 on placebo) were included in the analyses. Compared to placebo, the agomelatine group had a significant reduction in HAM-A total score at week 12 (between group difference: 6.30 ± 2.51, p = 0.012). Significant effects were also found for symptom response on the HAM-A (67.1% of patients on agomelatine vs. 32.5% on placebo) and symptom remission (38.8% of patients on agomelatine vs. 17.3% on placebo). Compared to placebo, there was a significant difference in favour of the agomelatine group at week 12 on the SDS total score (5.11 ± 1.81, p = 0.005). Significant effects were also found for functional response on the SDS (79.1% of patients on agomelatine vs. 43.2% of placebo) and functional remission (55.2% of patients on agomelatine vs. 25.4% on placebo). All findings for anxious symptoms and functional impairment were confirmed in the subset of more severely anxious patients. Agomelatine was well tolerated by patients.

Conclusion

This meta-analysis confirms that agomelatine reduces anxiety symptoms and improves the global functioning of GAD patients.

Supplementary Information

The online version of this article (10.1007/s12325-020-01583-9) contains supplementary material, which is available to authorized users.

[Anxiety in neurological practice]

Anxiety and related disorders are the most common type of mental disorders in both the general population and the neurological clinic. A current typology of anxiety disorders includes panic disorder, agoraphobia, simple (specific) phobias, social anxiety disorder, and generalized anxiety disorder. Anxiety disorders often accompany diseases of the nervous system, worsen their course and impede treatment, and the degree of anxiety usually corresponds to the severity of neurological symptoms. Anxiety may precede brain diseases, but the answer to the question of whether it contributes to these diseases or predicts them or can be an early manifestation of these diseases requires further studies. Modern approaches to the treatment of anxiety involve the use of benzodiazepines, antidepressants, some mood stabilizers, antipsychotics, as well as psychological interventions.

Pharmacotherapy of Anxiety Disorders: Current and Emerging Treatment Options

Anxiety disorders are the most prevalent psychiatric disorders and a leading cause of disability. While there continues to be expansive research in posttraumatic stress disorder (PTSD), depression and schizophrenia, there is a relative dearth of novel medications under investigation for anxiety disorders. This review's first aim is to summarize current pharmacological treatments (both approved and off-label) for panic disorder (PD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), and specific phobias (SP), including selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), azapirones (e.g., buspirone), mixed antidepressants (e.g., mirtazapine), antipsychotics, antihistamines (e.g., hydroxyzine), alpha- and beta-adrenergic medications (e.g., propranolol, clonidine), and GABAergic medications (benzodiazepines, pregabalin, and gabapentin). Posttraumatic stress disorder and obsessive-compulsive disorder are excluded from this review. Second, we will review novel pharmacotherapeutic agents under investigation for the treatment of anxiety disorders in adults. The pathways and neurotransmitters reviewed include serotonergic agents, glutamate modulators, GABAergic medications, neuropeptides, neurosteroids, alpha- and beta-adrenergic agents, cannabinoids, and natural remedies. The outcome of the review reveals a lack of randomized double-blind placebo- controlled trials for anxiety disorders and few studies comparing novel treatments to existing anxiolytic agents. Although there are some recent randomized controlled trials for novel agents including neuropeptides, glutamatergic agents (such as ketamine and d-cycloserine), and cannabinoids (including cannabidiol) primarily in GAD or SAD, these trials have largely been negative, with only some promise for kava and PH94B (an inhaled neurosteroid). Overall, the progression of current and future psychopharmacology research in anxiety disorders suggests that there needs to be further expansion in research of these novel pathways and larger-scale studies of promising agents with positive results from smaller trials.

Glutamate Systems in DSM-5 Anxiety Disorders: Their Role and a Review of Glutamate and GABA Psychopharmacology

Serotonin reuptake inhibitors and benzodiazepines are evidence-based pharmacological treatments for Anxiety Disorders targeting serotonin and GABAergic systems, respectively. Although clearly effective, these medications fail to improve anxiety symptoms in a significant proportion of patients. New insights into the glutamate system have directed attention toward drugs that modulate glutamate as potential alternative treatments for anxiety disorders. Here we summarize the current understanding of the potential role of glutamate neurotransmission in anxiety disorders and highlight specific glutamate receptors that are potential targets for novel anxiety disorder treatments. We also review clinical trials of medications targeting the glutamate system in DSM-5 anxiety disorders. Understanding the role of the glutamate system in the pathophysiology of anxiety disorder may aid in developing novel pharmacological agents that are effective in treating anxiety disorders.

Novel pharmacological targets in drug development for the treatment of anxiety and anxiety-related disorders

Current medication for anxiety disorders is suboptimal in terms of efficiency and tolerability, highlighting the need for improved drug treatments. In this review an overview of drugs being studied in different phases of clinical trials for their potential in the treatment of fear-, anxiety- and trauma-related disorders is presented. One strategy followed in drug development is refining and improving compounds interacting with existing anxiolytic drug targets, such as serotonergic and prototypical GABAergic benzodiazepines. A more innovative approach involves the search for compounds with novel mechanisms of anxiolytic action using the growing knowledge base concerning the relevant neurocircuitries and neurobiological mechanisms underlying pathological fear and anxiety. The target systems evaluated in clinical trials include glutamate, endocannabinoid and neuropeptide systems, as well as ion channels and targets derived from phytochemicals. Examples of promising novel candidates currently in clinical development for generalised anxiety disorder, social anxiety disorder, panic disorder, obsessive compulsive disorder or post-traumatic stress disorder include ketamine, riluzole, xenon with one common pharmacological action of modulation of glutamatergic neurotransmission, as well as the neurosteroid aloradine. Finally, compounds such as D-cycloserine, MDMA, L-DOPA and cannabinoids have shown efficacy in enhancing fear-extinction learning in humans. They are thus investigated in clinical trials as an augmentative strategy for speeding up and enhancing the long-term effectiveness of exposure-based psychotherapy, which could render chronic anxiolytic drug treatment dispensable for many patients. These efforts are indicative of a rekindled interest and renewed optimism in the anxiety drug discovery field, after decades of relative stagnation.

Description of the Treatment Course by Pregabalin for Anxiety in Patients With a Major Neurocognitive Disorder

BACKGROUND

Anxiety symptoms frequently experienced by patients with a major neurocognitive disorder (NCD) are often treated with long-term benzodiazepines despite known adverse effects. Pregabalin has shown efficacy in generalized anxiety disorders but has not been studied in patients with a major NCD. The objective of this study was to describe the use of pregabalin for anxiety in patient with a major NCD and the impact of its use on the pharmacological treatment change.

METHODS

A retrospective study was conducted using data of hospitalized patients in a cognitive-behavioral specialized unit between January 2015 and December 2017. Patients with a major NCD treated by pregabalin were included in this study. Data about the use of pregabalin (initiation and effective dosage, titration duration) and the use of other psychotropics were collected from the patients' medical records.

RESULTS

Thirty-three patients were included (mean age, 79.6 ± 11.7 years; 66.7% women). The mean duration of pregabalin titration was 18.6 ± 1.4 days, and the mean effective dosage was 200.0 ± 130.8 mg/d (range, 50-700 mg/d). At admission (before pregabalin use), 78.8% of patients were treated with a systematic prescription of benzodiazepine. At discharge (with pregabalin use), a significant decrease in patients with systematic prescription of benzodiazepine was observed (78.8% vs 33.3%, P = 0.001). During hospitalizations, no pregabalin treatment has been discontinued for lack of efficacy or for tolerance.

CONCLUSIONS

Larger controlled studies are needed to confirm the efficacy and the safety of pregabalin to treat anxiety symptoms associated with neurocognitive disorders.

Low-dose preoperative pregabalin improves postoperative pain management in septorhinoplasty surgery: a double-blind randomized clinical trial

PURPOSE

To evaluate the efficacy of single low dose (75 mg) preoperative pregabalin in reducing post-operative pain of septorhinoplasty.

METHODS

A double blind single center Randomized controlled trial based on block randomization. In the pregabalin group (PG) 34 participants received 75 mg pregabalin orally one hour before anesthesia induction while in control group (CG) 34 participants received a placebo. Pain and sedation were repeatedly measured with Visual Analouge Scale (VAS) and Riker Sedation-Agitation Scale (RSAS) respectively, 0.5, 1, 2, 6, 24 hours postextubation. Cumulative doses of fentanyl and ibuprofen received in both groups were compared.

RESULTS

Thirty-two of the participants in PG and 33 of the participants in CG completed the study. The Mean VAS pain score was less in PG versus CG 30 min postoperatively (2.30 ± 1.30 vs. 4.85 ± 1.17), one hour (2.28 ± 0.92 vs. 4.27 ± 0.78), two hours (2.11 ± 0.88 vs. 3.60 ± 0.61) and six hours (1.47 0.62 vs. 2.76 ± 0.91) but not 24-hours postoperatively (0.84 ± 0.62 vs. 1.09 ± 0.92). Participants in the PG were less agitated during early post-extubation period (at 10 min: RSAS 3.93 ± 0.43 vs. 4.42 ± 0.50) and more alert during the first hour post-extubation (at 60 min: RSAS 3.90 ± 0.29 vs. 3.36 ± 0.69). The total dose of rescue fentanyl and ibuprofen was lower in the PG compared to the CG.

CONCLUSIONS

A single dose of 75 mg pregabalin is very effective for pain control after septorhinoplasty procedure when administered one hour before anesthesia induction. Side effects are rare and opioid sparing was noted.

TRIAL REGISTRATION

Clinical trial number: IRCT2017043033706N1.

An 8-Week, Randomized, Phase 2, Double-Blind, Sequential Parallel-Group Comparison Study of Two Dose Levels of the GABAA Positive Allosteric Modulator PF-06372865 Compared With Placebo as an Adjunctive Treatment in Outpatients With Inadequate Response to Standard of Care for Generalized Anxiety Disorder

BACKGROUND

Generalized anxiety disorder (GAD) is a common psychiatric disorder, but many patients experience only partial relief of symptoms with existing therapies. Benzodiazepines are effective in many cases but are limited by a number of significant adverse effects. PF-06372865 is a subtype-selective gamma-aminobutyric acid A (GABAA)-positive allosteric modulator lacking in functional activity at alpha 1-containing receptors that are believed to mediate many of these adverse effects.

METHODS

PF-06372865 was evaluated as an adjunct to current GAD treatment in a double-blind, placebo-controlled, sequential parallel comparison study in patients with GAD who showed an incomplete response to current standard-of-care pharmacotherapy. A total of 90 subjects (of the planned 384) were randomized into the study before the decision to terminate the study. Two doses of PF-06372865 (2.5 mg twice daily and 7.5 mg twice daily) were compared with placebo.

RESULTS

Neither dose of PF-06372865 differentiated from placebo on week 4 Hamilton Anxiety Inventory total (primary end point) or on the Sheehan Disability Scale total score (secondary end point). Adverse events including dizziness, headache, and somnolence were observed, and the 7.5 mg dose demonstrated some impairment on the Digit Symbol Substitution test and the Epworth Sleepiness Scale relative to placebo and the 2.5 mg dose.

CONCLUSIONS

Factors contributing to the negative results include the limited sample size and failure to explore a broader range of doses.

Pharmacological treatments for generalised anxiety disorder: a systematic review and network meta-analysis

BACKGROUND

Generalised anxiety disorder is a disease that can be associated with substantial dysfunction. Pharmacological treatment is often the first choice for clinicians because of the cost and resource constraints of psychological alternatives, but there is a paucity of comparative information for the multiple available drug choices.

METHODS

A systematic review and network meta-analysis was performed on randomised trials in adult outpatients with generalised anxiety disorder identified from MEDLINE, Web of Science, Cochrane Library, ClinicalTrials.gov, Chinese National Knowledge Infrastructure (CNKI), Wanfang data, Drugs@FDA and commercial pharmaceutical registries. Placebo and active control trials were included. Data were extracted from all manuscripts and reports. Primary outcomes were efficacy (mean difference [MD] in change in Hamilton Anxiety Scale Score) and acceptability (study discontinuations for any cause). We estimated summary mean treatment differences and odds ratios using network meta-analyses with random effects. This study is registered with PROSPERO, number CRD42018087106.

FINDINGS

Studies were published between Jan 1, 1994 and Aug 1, 2017, in which 1992 potential studies were screened for inclusion. This analysis is based on 89 trials, which included 25 441 patients randomly assigned to 22 different active drugs or placebo. Duloxetine (MD -3·13, 95% credible interval [CrI] -4·13 to -2·13), pregabalin (MD -2·79, 95% CrI -3·69 to -1·91), venlafaxine (MD -2·69, 95% CrI -3·50 to -1·89), and escitalopram (MD -2·45, 95% CrI -3·27 to -1·63) were more efficacious than placebo with relatively good acceptability. Mirtazapine, sertraline, fluoxetine, buspirone, and agomelatine were also found to be efficacious and well tolerated but these findings were limited by small sample sizes. Quetiapine (MD -3·60 95% CrI -4·83 to -2·39) had the largest effect on HAM-A but it was poorly tolerated (odds ratio 1·44, 95% CrI 1·16-1·80) when compared with placebo. Likewise, paroxetine and benzodiazepines were effective but also poorly tolerated when compared with placebo. Risk of reporting bias was considered low, and when possible all completed studies were included to avoid publication bias.

INTERPRETATION

To our knowledge, this is the largest contemporary review of pharmacological agents for the treatment of generalised anxiety disorder by use of network analysis. There are several effective treatment choices for generalised anxiety disorder across classes of medication. The failure of initial pharmacological therapy might not be a reason to abandon a pharmacological treatment strategy.

FUNDING

No funding was received for this research.

Pharmacological Evaluation of Mentha spicata L. and Plantago major L., Medicinal Plants Used to Treat Anxiety and Insomnia in Colombian Caribbean Coast

Anxiety disorders are highly prevalent, chronic, and disabling conditions that impose enormous health and economic costs both on individuals and on society. Medicinal plants are an invaluable source of bioactive metabolites that can be useful as new pharmacological treatment. Teas from Mentha spicata and Plantago major are employed by Colombian populations to treat stress and insomnia. This work was conducted to evaluate their anxiolytic and hypnotic properties. For this, we employed the Elevated Plus-Maze test and the sodium pentobarbital-induced hypnosis method using Wistar rats. Oral administration of M. spicata extract (1000 mg/Kg) significantly increased the exploration and time spent in the open arms, which indicates its anxiolytic activity. On the other hand, both M. spicata and P. major extracts (1000 mg/Kg) remarkably augmented the sleeping time induced by pentobarbital, suggesting a sedative and hypnotic effect of the plants extracts. In addition, the acute toxicological study demonstrated that the doses used did not induce mortality or toxicity effects at hepatic or renal level. The bioactivity seems to be related to several kinds of constituents, mainly phenolic compounds such as flavonoids and tannins. In conclusion, these results reinforce the potential use of these species in the therapy of anxiety.

[Anxiety associated with substance abuse]

Substance abuse and anxiety is a common comorbid dyad and an example of so-called dual diagnosis in psychiatry. Comorbidity of anxiety and addictive disorders may be due to interdependence of these states as well as common predisposing factors and pathogenic mechanisms. There are various medicines in the treatment of anxiety associated with substance abuse, including benzodiazepines, calcium channel modulators, non-benzodiazepine anxiolytics, antidepressants and antipsychotics. One of the best approaches to the treatment of chronic anxiety disorders in drug treatment clinic is a long course of treatment with antidepressants, primarily with selective serotonin reuptake inhibitors as first line preparations. Such medications as pregabalin, buspirone, etifoxine and alimemazine are also of interest for the treatment of dual diagnosis patients.