Extrapyramidal Reactions Associated with Serotonergic Antidepressants

Exploring depression in Parkinson's disease: an Italian Delphi Consensus on phenomenology, diagnosis, and management

BACKGROUND

Depression is a prodromic and a frequent non-motor symptom of Parkinson's disease, associated to reduced quality of life and poor outcomes. The diagnosis of depression in parkinsonian patients represents a challenge due to the overlapping of symptoms typical of the two conditions.

METHODS

A Delphi panel survey was performed to reach a consensus amongst different Italian specialists on four main topics: the neuropathological correlates of depression, main clinical aspects, diagnosis, and management of depression in Parkinson's disease.

RESULTS AND CONCLUSION

Experts have recognized that depression is an established risk factor of PD and that its anatomic substrate is related to the neuropathological abnormalities typical of the disease. Multimodal and SSRI antidepressant have been confirmed as a valid therapeutic option in the treatment of depression in PD. Tolerability, safety profile, and potential efficacy on broad spectrum of symptoms of depression including cognitive symptoms and anhedonia should be considered when selecting an antidepressant and the choice should be tailored on the patients' characteristics.

Prevalence and causative drugs of drug-induced Parkinsonism in pediatric patients

Although several studies provided evidence on the epidemiology of drug-induced Parkinsonism (DIP) and its causative drugs, it is still limited in pediatrics. This study aimed to investigate the prevalence and risk of DIP in pediatrics. We used the Health Insurance Review and Assessment Service-Pediatric Patients Sample in Korea between 2010 and 2017 to estimate the annual prevalence of DIP and causative drug use using a cross-sectional design. The risk of DIP associated with causative drugs was evaluated using a case-crossover design. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated using a conditional logistic regression. A total of 2925 pediatric patients had diagnosed with DIP from 2010 to 2017. Most patients were aged between 12 and19 years old, and 99.8% had any diagnosis of mental health disorder (MHD). During the study period, the prevalence of DIP increased by 10.0-fold from 2010 to 2017. All causative drugs showed a corresponding increase in their use, with atypical antipsychotics being the most prominent (increase ratio, 2.07). For both in the prevalence of DIP and atypical antipsychotic use, the increment was much bigger in patients with non-psychotic MHD than that in patients with psychotic MHD. In the case-crossover study, antipsychotics showed the largest aOR with DIP. Risperidone among antipsychotics showed the highest risk for DIP (aOR = 7.09, 95% CI = 3.83-13.09), followed by aripiprazole (aOR = 5.03, 95% CI = 2.88-8.80). This study suggests that the increase in DIP prevalence in pediatric patients might be because of the increased use of atypical antipsychotics.

"Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies

Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.

Single-Nucleotide Polymorphisms as Biomarkers of Antipsychotic-Induced Akathisia: Systematic Review

Antipsychotic-induced akathisia (AIA) is a movement disorder characterized by a subjective feeling of inner restlessness or nervousness with an irresistible urge to move, resulting in repetitive movements of the limbs and torso, while taking antipsychotics (APs). In recent years, there have been some associative genetic studies of the predisposition to the development of AIA. Objective: The goal of our study was to review the results of associative genetic and genome-wide studies and to systematize and update the knowledge on the genetic predictors of AIA in patients with schizophrenia (Sch). Methods: We searched full-text publications in PubMed, Web of Science, Springer, Google Scholar, and e-Library databases from 1977 to 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) quality scale was used for the critical selection of the studies. Results: We identified 37 articles, of which 3 were included in the review. Thus, the C allele of rs1800498 (59414 C>T) and the A allele of rs1800497 (17316 G>A) (TaqIA) from the DRD2 gene as well as the TT genotype rs13212041 (77461407 C>T) from the HTR1B gene were found to be associated with AIA. Conclusions: Uncovering the genetic biomarkers of AIA may provide a key to developing a strategy for the personalized prevention and treatment of this adverse neurological drug reaction of APs in patients with Sch in real clinical practice.

Drug-Induced Movement Disorders

Drug-induced movement disorders (DIMDs) are most commonly associated with typical and atypical antipsychotics. However, other drugs such as antidepressants, antihistamines, antiepileptics, antiarrhythmics, and gastrointestinal drugs can also cause abnormal involuntary movements. Different types of movement disorders can also occur because of adverse drug reactions. Therefore, the important key to diagnosing DIMDs is a causal relationship between potential offending drugs and the occurrence of abnormal movements. The pathophysiology of DIMDs is not clearly understood; however, many cases of DIMDs are thought to exert adverse mechanisms of action in the basal ganglia. The treatment of some DIMDs is quite challenging, and removing the offending drugs may not be possible in some conditions such as withdrawing antipsychotics in the patient with partially or uncontrollable neuropsychiatric conditions. Future research is needed to understand the mechanism of DIMDs and the development of drugs with better side-effect profiles. This article reviews the phenomenology, diagnostic criteria, pathophysiology, and management of DIMDs.

Atypical dyskinesias under treatment with antipsychotic drugs: Report from the AMSP multicenter drug safety project

OBJECTIVES

The aim of this study was to describe atypical dyskinesias (AtypDs) occurring during treatment with antipsychotic drugs (APDs). AtypDs are dyskinesias showing either an unusual temporal relationship between onset of treatment and start of the adverse drug reaction (ADR) or an unusual presentation of clinical symptoms.

METHODS

Data on the utilisation of APDs and reports of severe APD-induced AtypDs were collected using data from the observational pharmacovigilance programme - 'Arzneimittelsicherheit in der Psychiatrie (English: drug safety in psychiatry)' (AMSP) - from 1993 to 2016.

RESULTS

A total of 495,615 patients were monitored, of which 333,175 were treated with APDs. Sixty-seven cases (0.020%) of severe AtypDs under treatment with APDs were registered. The diagnoses of schizophrenic disorders as well as organic mental disorders were related to significantly higher rates of AtypDs. Second-generation antipsychotic drugs (SGAs) showed slightly higher rates of AtypDs (0.024%) than high-potency (0.011%) or low-potency first-generation antipsychotic drugs (FGAs; 0.006%). In 41 cases (61.2%), two or more drugs were found to cause AtypDs.

CONCLUSIONS

Our study indicates that AtypDs are rare ADRs. SGAs may have a higher risk for the occurrence of AtypDs than FGAs. Clinicians should be aware of this ADR and patients should be monitored and examined carefully.

Comparison of pramipexole and citalopram in the treatment of depression in Parkinson's disease: A randomized parallel-group trial

Background:

Materials and Methods:

Results:

Conclusion:

Selective Serotonin Reuptake Inhibitors and Adverse Effects: A Narrative Review

Depression is the most prevalent psychiatric disorder in the world, affecting 4.4% of the global population. Despite an array of treatment modalities, depressive disorders remain difficult to manage due to many factors. Beginning with the introduction of fluoxetine to the United States in 1988, selective serotonin reuptake inhibitors (SSRIs) quickly became a mainstay of treatment for a variety of psychiatric disorders. The primary mechanism of action of SSRIs is to inhibit presynaptic reuptake of serotonin at the serotonin transporter, subsequently increasing serotonin at the postsynaptic membrane in the serotonergic synapse. The six major SSRIs that are marketed in the USA today, fluoxetine, citalopram, escitalopram, paroxetine, sertraline, and fluvoxamine, are a group of structurally unrelated molecules that share a similar mechanism of action. While their primary mechanism of action is similar, each SSRI has unique pharmacokinetics, pharmacodynamics, and side effect profile. One of the more controversial adverse effects of SSRIs is the black box warning for increased risk of suicidality in children and young adults aged 18–24. There is a lack of understanding of the complexities and interactions between SSRIs in the developing brain of a young person with depression. Adults, who do not have certain risk factors, which could be confounding factors, do not seem to carry this increased risk of suicidality. Ultimately, when prescribing SSRIs to any patient, a risk–benefit analysis must factor in the potential treatment effects, adverse effects, and dangers of the illness to be treated. The aim of this review is to educate clinicians on potential adverse effects of SSRIs.

Chronic serotonin syndrome: A retrospective study

BACKGROUND

Serotonin syndrome (SS) is an underdiagnosed drug-induced clinical syndrome resulting from the excess intrasynaptic concentration of serotonin. Very limited information is available about chronic SS.

AIM

To evaluate the epidemiological, clinical, and other aspects of the insidious onset SS.

METHODS

We retrospectively evaluated 14 consecutive adult patients (> 18 years) who had complaints for more than 6 wk at the time of consultation and met the Hunter criteria for SS.

RESULTS

The mean age was 41.1 years (range: 21-61 years), with a male preponderance (64%). Although tremors were observed in all patients, this was a presenting complaint in only 43% of patients. Generalized body pain, insomnia, and restlessness were common presenting features (50% each). Other common clinical features were stiffness of the limbs (43%), diaphoresis (43%), gait disturbances (36%), bowel disturbances (36%), dizziness (29%), sexual dysfunctions (21%), incoordination (14%), and fatigue (14%) The mean duration of symptoms before the diagnosis of SS was 13.5 ± 5.8 wk (range: 6-24 wk). Amitriptyline was the most common drug (n = 6, 43%), followed by tramadol (n = 5, 36%) and sodium valproate (n = 5, 36%). All patients received cyproheptadine, a 5- hydroxytryptamine2A antagonist, as treatment and noted an excellent response over the course of 4-14 d.

CONCLUSION

This study represents the largest study on chronic SS. We suggest that patients receiving serotonergic drugs should be physically examined for the presence of SS upon the development of new symptoms.

Acute dystonia following epileptic seizure after bupropion intoxication

Bupropion is an effective treatment for major depressive disorder and smoking cessation. In this paper, we present a case report about dystonia in the head and the neck after epileptic seizures due to 4200 mg of extended-release bupropion intake, and we aim to take attention to the rare neuropsychiatric side effects that may occur after the use of high doses of bupropion.

Focus on Depression in Parkinson's Disease: A Delphi Consensus of Experts in Psychiatry, Neurology, and Geriatrics

Major and minor forms of depression are significant contributors to Parkinson's disease morbidity and caregiver burden, affecting up to 50% of these patients. Nonetheless, symptoms of depression are still underrecognized and undertreated in this context due to scarcity of evidence and, consequently, consistent clinical guideline recommendations. Here, we carried out a prospective, multicentre, 2-round modified Delphi survey with 49 questions about the aetiopathological mechanisms of depression in Parkinson's disease (10), clinical features and connections with motor and nonmotor symptoms (10), diagnostic criteria (5), and therapeutic options (24). Items were assessed by a panel of 37 experts (neurologists, psychiatrists, and a geriatrist), and consensus was achieved in 81.6% of them. Depressive symptoms, enhanced by multiple patient circumstances, were considered Parkinson's disease risk factors but not clinical indicators of motor symptom and disease progression. These patients should be systematically screened for depression while ruling out both anhedonia and apathy symptoms as they are not necessarily linked to it. Clinical scales (mainly the Geriatric Depression Scale GDS-15) can help establishing the diagnosis of depression, the symptoms of which will require treatment regardless of severity. Efficacious and well-tolerated pharmacological options for Parkinson's comorbid depression were selective serotonin reuptake inhibitors (especially sertraline), dual-action serotonin and norepinephrine reuptake inhibitors (venlafaxine, desvenlafaxine, and duloxetine), multimodal (vortioxetine, bupropion, mirtazapine, and tianeptine), and anti-Parkinsonian dopamine agonists (pramipexole, ropinirole, and rotigotine). Tricyclic antidepressants and combining type B monoamine oxidase inhibitors with serotonergic drugs have serious side effects in these patients and therefore should not be prescribed. Electroconvulsive therapy was indicated for severe and drug-refractory cases. Cognitive behavioural therapy was recommended in cases of mild depression. Results presented here are useful diagnostic and patient management guidance for other physicians and important considerations to improve future drug trial design.

Atraumatic trismus induced by duloxetine: an uncommon presentation of acute dystonia

Atraumatic trismus can be one of the presentations of medication-induced acute dystonia, particularly by antipsychotics and less commonly antidepressants. A case of an unusual emergency presentation of atraumatic trismus on initiation of duloxetine is reported. The patient was a 40-year-old woman experiencing sudden difficulty in mouth opening and speaking due to a stiffened jaw after taking 5 days of duloxetine prescribed for her fibromyalgia-related chest pain. Assessment of vital signs is prudent to ensure there is no laryngeal involvement. Other physical examinations and her recent investigations were unremarkable. She was treated for acute dystonia and intravenous procyclidine was given together with oral diazepam. Her symptoms improved immediately and her duloxetine was suggested to be stopped. To our knowledge, this is the first case of isolated trismus induced by duloxetine. Clinicians should be aware of this risk, especially considering the limitation of important physiological functions (such as swallowing, eating, etc) associated with this condition.

Movement disorders induced by psychiatric drugs that do not block dopamine receptors

Most movement disorders in psychiatric patients are induced by neuroleptic antipsychotic medications, all of which are dopamine D2 receptor blocking drugs. These include: acute onset disorders: dystonic reactions, akathisia and the neuroleptic malignant syndrome (NMS); non-acute onset parkinsonism; and the tardive syndromes. However, many other medications, when used at recommended doses, also induce movement disorders, with tremor being the most common. With the exception of serotonin syndrome, they are rarely as severe or disabling as the neuroleptic extrapyramidal syndromes may be. The serotonin reuptake inhibiting (SSRI) drugs are associated with the serotonin syndrome, a life-threatening disorder, but may also cause tremor and akathisia. While SSRI's have been thought to occasionally cause a tardive dyskinesia-like syndrome, this almost never occurs without prior or concurrent neuroleptic exposure as well. There also are few reliable data to support an association between antidepressants and parkinsonism. Valproic acid has been shown to cause parkinsonism, and lithium may as well, in addition to both having the well-known side effect of tremors. Myoclonus and asterixis are usually induced by toxic levels of medications but may appear with therapeutic levels, particularly with anticonvulsant mood stabilizers, and clozapine. Ataxia rarely occurs with non-toxic levels of drug, particularly anticonvulsants, benzodiazepines and lithium.

Antidepressants and movement disorders: a postmarketing study in the world pharmacovigilance database

BACKGROUND

Antidepressants-induced movement disorders are rare and imperfectly known adverse drug reactions. The risk may differ between different antidepressants and antidepressants' classes. The objective of this study was to assess the putative association of each antidepressant and antidepressants' classes with movement disorders.

METHODS

Using VigiBase®, the WHO Pharmacovigilance database, disproportionality of movement disorders' reporting was assessed among adverse drug reactions related to any antidepressant, from January 1967 to February 2017, through a case/non-case design. The association between nine subtypes of movement disorders (akathisia, bruxism, dystonia, myoclonus, parkinsonism, restless legs syndrome, tardive dyskinesia, tics, tremor) and antidepressants was estimated through the calculation first of crude Reporting Odds Ratio (ROR), then adjusted ROR on four potential confounding factors: age, sex, drugs described as able to induce movement disorders, and drugs used to treat movement disorders.

RESULTS

Out of the 14,270,446 reports included in VigiBase®, 1,027,405 (7.2%) contained at least one antidepressant, among whom 29,253 (2.8%) reported movement disorders. The female/male sex ratio was 2.15 and the mean age 50.9 ± 18.0 years. We found a significant increased ROR for antidepressants in general for all subtypes of movement disorders, with the highest association with bruxism (ROR 10.37, 95% CI 9.62-11.17) and the lowest with tics (ROR 1.49, 95% CI 1.38-1.60). When comparing each of the classes of antidepressants with the others, a significant association was observed for all subtypes of movement disorders except restless legs syndrome with serotonin reuptake inhibitors (SRIs) only. Among antidepressants, mirtazapine, vortioxetine, amoxapine, phenelzine, tryptophan and fluvoxamine were associated with the highest level to movement disorders and citalopram, paroxetine, duloxetine and mirtazapine were the most frequently associated with movement disorders. An association was also found with eight other antidepressants.

CONCLUSIONS

A potential harmful association was found between movement disorders and use of the antidepressants mirtazapine, vortioxetine, amoxapine, phenelzine, tryptophan, fluvoxamine, citalopram, paroxetine, duloxetine, bupropion, clomipramine, escitalopram, fluoxetine, mianserin, sertraline, venlafaxine and vilazodone. Clinicians should beware of these adverse effects and monitor early warning signs carefully. However, this observational study must be interpreted as an exploratory analysis, and these results should be refined by future epidemiological studies.

Iatrogenesis and neurological manifestations in the elderly

Older people are often exposed to polypharmacy in a multimorbidity context. Inappropriate polypharmacy is often harmful, increasing the risk of inappropriate prescriptions and therefore adverse drug events (ADEs). Five to 20% of all hospital admissions are related to ADE in older people, among which 40 to 70% could be prevented. However, identifying ADEs and drug-related admissions in the elderly is challenging because ADEs often present as common geriatric problems such as falls, delirium, which might be due to the aging process, underlying diseases, and/or medications. In the pharmacovigilance database of the World Health Organization, drug-related neurological manifestations are the third reported cause of ADEs in the elderly, and neurological drugs are the third leading class of medications involved in ADEs. We must therefore be particularly vigilant, both in our prescriptions but also in our diagnoses to avoid prescribing inappropriate treatments and detect ADEs. Even though multiple pharmacologic changes occur in the elderly (absorption, distribution, drug metabolism and excretion), most of medications are still often prescribed at the same daily dosage as in young adults. When prescribing any drug for old patients, we should remember that daily intake should be adapted to these specificities, keeping in mind the old well-known aphorism "start low, go slow". In this review, we describe the main drug-related neurological manifestations (drug-induced movement disorders, falls, seizures, delirium, hypoglycemia, stroke, hyponatremia, peripheral neuropathy and myopathy, and serotonin syndrome) and the main drugs associated with neurological manifestations (dopamine receptor blocking agents, antithrombotics, anticholinergics, beta-lactams, antidepressants, benzodiazepines, mood stabilizers).

Extrapyramidal reactions following treatment with antidepressants: Results of the AMSP multinational drug surveillance programme

Objectives: Extrapyramidal symptoms (EPS) are a common adverse effect of antipsychotics. However, there are case reports describing EPS following treatment with antidepressants. It is not fully understood how antidepressants cause EPS, but a serotonergic input to dopaminergic pathways is a probable mechanism of action.Methods: Data from a multicenter drug-surveillance programme (AMSP, 'drug safety in psychiatry') which systemically documents severe drug reactions during psychiatric inpatient admissions, were reviewed to assess for EPS associated with antidepressant treatment. We identified 15 such cases, which were studied to detect similarities and to characterise risk factors.Results: We report on 15 patients with EPS following antidepressant-therapy between 1994 and 2016. EPS frequently occurred with selective serotonin reuptake inhibitor (SSRI) treatment alone (7/15 cases) or concomitant SSRI treatment (6/15 cases). EPS were most frequent with escitalopram-treatment (5 cases). The most common EPS was atypical dyskinesia (6/15 cases) followed by akathisia (4/15 cases). The mean age of onset for EPS was 54.93 years (SD 17.9). EPS occurred at any dosage and equally often in men and women.Conclusions: Our results highlight the possibility of EPS as an important, although uncommon, adverse effect of antidepressants. Clinicians should beware of this adverse effect and monitor early warning signs carefully.

HTR1A, HTR1B, HTR2A, HTR2C and HTR6 Gene Polymorphisms and Extrapyramidal Side Effects in Haloperidol-Treated Patients with Schizophrenia

Schizophrenia is a serious, chronic psychiatric disorder requiring lifelong treatment. Extrapyramidal side effects (EPS) are common adverse reactions to antipsychotic medications. In addition to the dopaminergic system, serotonergic mechanisms, including serotonin (5-HT) receptors, might be involved in EPS development. This study aimed to examine molecular associations of HTR1A, HTR1B, HTR2A, HTR2C and HTR6 gene polymorphisms with acute EPS in 229 male schizophrenia patients, following two weeks of haloperidol monotherapy. The Simpson-Angus Rating Scale for Extrapyramidal Side Effects (SAS), Barnes Akathisia Rating Scale (BARS) and Extrapyramidal Symptom Rating Scale (ESRS) were used to evaluate EPS severity. Genotyping was performed using real-time PCR, following extraction of blood DNA. Significant acute EPS appeared in 48.03% of schizophrenia patients. For the rs13212041 HTR1B gene polymorphism, affecting microRNA regulation of HTR1B gene expression, a higher frequency of TT carriers was found among haloperidol-treated patients with akathisia when compared to the group without akathisia symptoms. In comparison to C-allele carriers, patients carrying the TT genotype had higher akathisia severity, as determined by the SAS, BARS and ESRS scales. These molecular findings suggest potential involvement of 5-HT_1B receptors in akathisia development following haloperidol treatment, as well as possible epigenetic mechanisms of serotonergic modulation associated with antipsychotic-induced EPS.

5-HT2C receptor blockade reverses SSRI-associated basal ganglia dysfunction and potentiates therapeutic efficacy

Serotonin (5-HT) selective reuptake inhibitors (SSRIs) are widely used in the treatment of depression and anxiety disorders, but responsiveness is uncertain and side effects often lead to discontinuation. Side effect profiles suggest that SSRIs reduce dopaminergic (DAergic) activity, but specific mechanistic insight is missing. Here we show in mice that SSRIs impair motor function by acting on 5-HT2C receptors in the substantia nigra pars reticulata (SNr), which in turn inhibits nigra pars compacta (SNc) DAergic neurons. SSRI-induced motor deficits can be reversed by systemic or SNr-localized 5-HT2C receptor antagonism. SSRIs induce SNr hyperactivity and SNc hypoactivity that can also be reversed by systemic 5-HT2C receptor antagonism. Optogenetic inhibition of SNc DAergic neurons mimics the motor deficits due to chronic SSRI treatment, whereas local SNr 5-HT2C receptor antagonism or optogenetic activation of SNc DAergic neurons reverse SSRI-induced motor deficits. Lastly, we find that 5-HT2C receptor antagonism potentiates the antidepressant and anxiolytic effects of SSRIs. Together our findings demonstrate opposing roles for 5-HT2C receptors in the effects of SSRIs on motor function and affective behavior, highlighting the potential benefits of 5-HT2C receptor antagonists for both reduction of motor side effects of SSRIs and augmentation of therapeutic antidepressant and anxiolytic effects.

22q11.2 Deletion Syndrome-Associated Parkinson's Disease

BACKGROUND

22q11.2 deletion syndrome (22q11.2DS) is a multisystem condition associated with an increased risk of early-onset Parkinson's disease (PD).

METHODS

We review the clinical, neuroimaging, and neuropathological observations, as well as diagnostic challenges, of PD in 22q11.2DS. We conducted a search of PubMed up until June 1, 2018 and personal files to identify relevant publications.

RESULTS

22q11.2DS-associated PD is responsible for approximately 0.5% of early-onset PD. The hallmark motor symptoms and neuropathology of PD, and typical findings of reduced striatal dopamine transporter binding with molecular imaging, are present in 22q11.2DS-associated PD. Mean age at PD onset in 22q11.2DS is relatively young (∼40 years). Patients with 22q11.2DS-associated PD show a good response to levodopa.

CONCLUSIONS

Further recognition of 22q11.2DS and study of PD in people with 22q11.2DS could provide insights into the mechanisms that cause PD in the general population. 22q11.2DS may serve as an identifiable PD model to study prodromal PD and disease-modifying treatments.

Tardive Dyskinesia-like Syndrome Due to Drugs that do not Block Dopamine Receptors: Rare or Non-existent: Literature Review

Background

Although tardive dyskinesia (TD) is most commonly defined as a movement disorder caused by chronic exposure to dopamine‐receptor‐blocking drugs (DRBDs), it has also been thought to result from exposure to some non‐DRBDs.

Methods

We critiqued many reviews making the association between non‐DRBDs and a TD‐like syndrome and almost all case reports. We checked whether cases met criteria for the diagnosis of TD‐like syndrome and whether DRBDs had been excluded.

Results

We found that both tricyclic antidepressants and selective serotonin reuptake inhibitor antidepressants may unmask or exacerbate TD after prior exposure to or with concurrent use of DRBDs. We found support for its existence outside of this context to be extremely weak.

Discussion

There is little evidence that drugs other than DRBDs by themselves cause a TD syndrome; most reported cases appear to occur as a result of a “priming” effect induced by a DRBD, which is later unmasked.

Association of Antidepressant Use With Drug-Related Extrapyramidal Symptoms: A Pharmacoepidemiological Study

BACKGROUND

Antidepressants are one of the most prescribed classes of medications. A number of case reports have linked these drugs to extrapyramidal symptoms (EPSs), but no large epidemiologic study to date has examined this association. We sought to quantify the association of EPSs with different antidepressants by undertaking a large pharmacoepidemiologic study.

METHODS

A nested case-control study was conducted using a large health claims database in the United States from June 2006 to December 2015. Subjects with a diagnosis of primary Parkinson disease and those who received prescriptions of levodopa, ropinirole, pramipexole, domperidone, metoclopramide, entacapone, benztropine, selegiline, rasagiline, diphenhydramine, trihexyphenidyl, typical and atypical antipsychotics, and tricyclic antidepressants were excluded. Cases were followed to the first billing code for an extrapyramidal event or last date of enrollment in the cohort. For each case, 10 control subjects were matched by follow-up time, calendar time, and age through density-based sampling. Rate ratios were computed using conditional logistic regression adjusting for other covariates.

RESULTS

We identified 3,838 subjects with EPSs compared with 38,380 age-matched control subjects. Rate ratios with respect to EPSs were as follows: duloxetine, 5.68 (95% confidence interval [CI], 4.29-7.53); mirtazapine, 3.78 (95% CI, 1.71-8.32); citalopram, 3.47 (95% CI, 2.68-4.50); escitalopram, 3.23 (95% CI, 2.44-4.26); paroxetine, 3.07 (95% CI, 2.15-4.40); sertraline, 2.57 (95% CI, 2.02-3.28); venlafaxine, 2.37 (95% CI, 1.71-3.29); bupropion, 2.31 (95% CI, 1.67-3.21); and fluoxetine, 2.03 (95% CI, 1.48-2.78).

CONCLUSIONS

This observational study demonstrates a harmful association between the incidence of Parkinson disease or associated EPSs and use of the antidepressants duloxetine, mirtazapine, citalopram, escitalopram, paroxetine, sertraline, venlafaxine, bupropion, and fluoxetine.

A randomised controlled trial of the monoaminergic stabiliser (-)-OSU6162 in treatment of myalgic encephalomyelitis/chronic fatigue syndrome

OBJECTIVE

The monoaminergic stabiliser (-)-OSU6162 has in previous studies shown promising effects on mental fatigue after stroke and traumatic brain injury. This study investigated the safety and effectiveness of (-)-OSU6162 in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

METHODS

A total of 62 patients were randomly assigned to placebo or (-)-OSU6162. Primary outcomes were assessment on the mental fatigue scale (MFS) and the clinical global impression of change (CGI-C) scale. Secondary outcomes were results on the FibroFatigue scale (FF), the Beck Depression Inventory (BDI), the pain visual analogue scale and neuropsychological tests. Assessments were performed at baseline, after 1 and 2 weeks of treatment and at follow-up after 6 weeks.

RESULTS

MFS and CGI-C showed significant improvements for both treatment groups after treatment but not at follow-up; a similar pattern was seen for FF and BDI. However, significant differences between groups could not be demonstrated. On the other hand, correlation analyses showed a significant correlation between (-)-OSU6162 concentration and change in MFS, FF, and BDI score within the concentration interval 0.1-0.7 µM. Exploratory subgroup analyses showed a larger treatment effect with (-)-OSU6162 in improving MFS and FF symptoms in patients on antidepressant therapy compared to those without antidepressant treatment.

CONCLUSION

(-)-OSU6162 was found to be safe and well tolerated. When analysing the entire material (-)-OSU6162 was not found to differ significantly from placebo in alleviating fatigue in ME patients but was superior to placebo in counteracting fatigue in a subgroup of ME patients who received concomitant pharmacological treatment for depression.

The Safety, Tolerability and Risks Associated with the Use of Newer Generation Antidepressant Drugs: A Critical Review of the Literature

Newer generation antidepressant drugs (ADs) are widely used as the first line of treatment for major depressive disorders and are considered to be safer than tricyclic agents. In this critical review, we evaluated the literature on adverse events, tolerability and safety of selective serotonin reuptake inhibitors, serotonin noradrenaline reuptake inhibitors, bupropion, mirtazapine, trazodone, agomelatine, vilazodone, levomilnacipran and vortioxetine. Several side effects are transient and may disappear after a few weeks following treatment initiation, but potentially serious adverse events may persist or ensue later. They encompass gastrointestinal symptoms (nausea, diarrhea, gastric bleeding, dyspepsia), hepatotoxicity, weight gain and metabolic abnormalities, cardiovascular disturbances (heart rate, QT interval prolongation, hypertension, orthostatic hypotension), genitourinary symptoms (urinary retention, incontinence), sexual dysfunction, hyponatremia, osteoporosis and risk of fractures, bleeding, central nervous system disturbances (lowering of seizure threshold, extrapyramidal side effects, cognitive disturbances), sweating, sleep disturbances, affective disturbances (apathy, switches, paradoxical effects), ophthalmic manifestations (glaucoma, cataract) and hyperprolactinemia. At times, such adverse events may persist after drug discontinuation, yielding iatrogenic comorbidity. Other areas of concern involve suicidality, safety in overdose, discontinuation syndromes, risks during pregnancy and breast feeding, as well as risk of malignancies. Thus, the rational selection of ADs should consider the potential benefits and risks, likelihood of responsiveness to the treatment option and vulnerability to adverse events. The findings of this review should alert the physician to carefully review the appropriateness of AD prescription on an individual basis and to consider alternative treatments if available.

Revisiting Antipsychotic-induced Akathisia: Current Issues and Prospective Challenges

BACKGROUND

Akathisia continues to be a significant challenge in current neurological and psychiatric practice. Prompt and accurate detection is often difficult and there is a lack of consensus concerning the neurobiological basis of akathisia. No definitive treatment has been established for akathisia despite numerous preclinical and clinical studies.] Method: We reviewed antipsychotic-induced akathisia including its clinical presentation, proposed underlying pathophysiology, current and under investigation therapeutic strategies.

CONCLUSION

Despite the initial promise that second generation antipsychotics would be devoid of akathisia effects, this has not been confirmed. Currently, there are limited therapeutic options for the clinical practice and the evidence supporting the most widely used treatments (beta blockers, anticholinergic drugs) is still absent or inconsistent.

Diagnosis and Management of Dystonia

PURPOSE OF REVIEW

This article highlights the clinical and diagnostic tools used to assess and classify dystonia and provides an overview of the treatment approach.

RECENT FINDINGS

In the past 4 years, the definition and classification of dystonia have been revised, and new genes have been identified in patients with isolated hereditary dystonia (DYT23, DYT24, and DYT25). Expanded phenotypes were reported in patients with combined dystonia, such as those with mutations in ATP1A3. Treatment offerings have expanded as there are more neurotoxins, and deep brain stimulation has been employed successfully in diverse populations of patients with dystonia.

SUMMARY

Diagnosis of dystonia rests upon a clinical assessment that requires the examiner to understand the characteristic disease features that are elicited through a careful history and physical examination. The revised classification system uses two distinct nonoverlapping axes: clinical features and etiology. A growing understanding exists of both isolated and combined dystonia as new genes are identified and our knowledge of the phenotypic presentation of previously reported genes has expanded. Genetic testing is commercially available for some of these conditions. Treatment options for dystonia include pharmacologic therapy, chemodenervation, and surgical intervention. Deep brain stimulation benefits many patients with various types of dystonia.

Neurologic Complications of Commonly Used Drugs in the Hospital Setting

This chapter reviews the neurologic complications of medications administered in the hospital setting, by class, introducing both common and less common side effects. Detail is devoted to the interaction between pain, analgesia, sedation, and their residual consequences. Antimicrobials are given in nearly every hospital setting, and we review their capacity to produce neurologic sequelae with special devotion to cefepime and the antiviral treatment of human immunodeficiency virus. The management of hemorrhagic stroke has become more complex with the introduction of novel oral anticoagulants, and we provide an update on what is known about reversal of the new oral anticoagulants. Both central and peripheral nervous system complications of immunosuppressants and chemotherapies are reviewed. Because diagnosis is generally based on clinical acumen, alone, neurotoxic syndromes resulting from psychotropic medications may be easily overlooked until severe dysautonomia develops. We include a practical approach to the diagnosis of serotonin syndrome and neuroleptic malignant syndrome.

Antidepressants in Parkinson's disease. Recommendations by the movement disorder study group of the Neurological Association of Madrid

INTRODUCTION

Although antidepressants are widely used in Parkinson's disease (PD), few well-designed studies to support their efficacy have been conducted.

DEVELOPMENT

These clinical guidelines are based on a review of the literature and the results of an AMN movement disorder study group survey.

CONCLUSIONS

Evidence suggests that nortriptyline, venlafaxine, paroxetine, and citalopram may be useful in treating depression in PD, although studies on paroxetine and citalopram yield conflicting results. In clinical practice, however, selective serotonin reuptake inhibitors are usually considered the treatment of choice. Duloxetine may be an alternative to venlafaxine, although the evidence for this is less, and venlafaxine plus mirtazapine may be useful in drug-resistant cases. Furthermore, citalopram may be indicated for the treatment of anxiety, atomoxetine for hypersomnia, trazodone and mirtazapine for insomnia and psychosis, and bupropion for apathy. In general, antidepressants are well tolerated in PD. However, clinicians should consider the anticholinergic effect of tricyclic antidepressants, the impact of serotonin-norepinephrine reuptake inhibitors on blood pressure, the extrapyramidal effects of antidepressants, and any potential interactions between monoamine oxidase B inhibitors and other antidepressants.

The clinical challenges of akathisia

Akathisia is one of the most vexing problems in neuropsychiatry. Although it is one of the most common side effects of antipsychotic medications, it is often difficult to describe by patients, and is difficult to diagnose and treat by practitioners. Akathisia is usually grouped with extrapyramidal movement disorders (ie, movement disorders that originate outside the pyramidal or corticospinal tracts and generally involve the basal ganglia). Yet, it can present as a purely subjective clinical complaint, without overt movement abnormalities. It has been subtyped into acute, subacute, chronic, tardive, withdrawal-related, and "pseudo" forms, although the distinction between many of these is unclear. It is therefore not surprising that akathisia is generally either underdiagnosed or misdiagnosed, which is a serious problem because it can lead to such adverse outcomes as poor adherence to medications, exacerbation of psychiatric symptoms, and, in some cases, aggression, violence, and suicide. In this article, we will attempt to address some of the confusion surrounding the condition, its relationship to other disorders, and differential diagnosis, as well as treatment alternatives.