Factors potentiating the risk of mirtazapine-associated restless legs syndrome

From parasomnia to agrypnia excitata - An illustrative case on diagnostic approach

The diagnostic approach to sleep-related movements disorders is seldom discussed. We report a case of fatal familial insomnia who initially presented with persistent limb movements in sleep, which later progressed to a state of agrypnia excitata. Here, the evaluation of abnormal movements in sleep is discussed using a step-by-step diagnostic approach. Although no cure is available for fatal familial insomnia, prompt recognition of this condition is important to facilitate proper management, including the involvement of interdisciplinary neuropalliative care.

Relative frequency of drug-induced sleep disorders for 32 antidepressants in a large set of Internet user reviews

STUDY OBJECTIVES

It is known that antidepressant drugs can induce sleep disorders in patients, but little data exist about high or low-risk molecules. The aim was to study the frequency of antidepressant drugs-induced sleep disorders (DISD) by molecule.

METHODS

77,391 patient comments for 32 antidepressant drugs were collected from drug review websites and screened for DISD. Association between drugs and nightmare disorder, restless legs syndrome, sleep paralysis, sleep terrors, sleep-related hallucinations or sleep walking was expressed as relative proportion [proportional reporting ratio (PRR)]. A detailed analysis of the dreams content was also carried out.

RESULTS

Amitriptyline, doxepin, fluvoxamine, mirtazapine, nortriptyline, trazodone, venlafaxine and vilazodone were associated with a greater frequency of DISD compared to other antidepressants. Vilazodone heavily increased the probability of developing 5 of the 6 studied DISD (PRR 3.3 to 19.3) and mirtazapine increased the probability for developing 4 DISD (PRR 2.4 to 6.4). Bupropion and citalopram were associated with lower probabilities for 5 DISD (PRR 0.2 to 0.7). Sentiment analysis showed that patients described disturbing dreams for vilazodone or mirtazapine and strange but less negative dreams for bupropion, citalopram or duloxetine.

CONCLUSIONS

Relative frequencies of sleep disorders were obtained for a vast panel of antidepressant drugs through an original analysis of user's drug reviews on drug rating websites. Our results could guide clinicians in appropriate choice of antidepressant drug for high DISD-risk patients in need of such treatment. These results may however be cautiously taken, considering the uncertain reliability and generalisability of web-based data.

Mirtazapine-associated movement disorders: A literature review

Mirtazapine (MTZ) is an atypical antidepressant approved by the FDA, which mechanism of action involves the antagonism of alpha-2, H1, 5-HT2A, 5-HT2C, and 5-HT3 receptors. In this context, the aim of this literature review is to evaluate the clinical epidemiological profile, pathological mechanisms, and management of MTZ-associated movement disorders (MDs). Relevant reports of six databases were identified and assessed by two reviewers without language restriction. Fifty-two reports containing 179 cases from 20 countries were assessed. The mean age was 57 year (range, 17-85). The majority of the individuals were female (60%) and of European origin. The mean time from MTZ start to symptom onset was 7.54 days; the time from management to MD improvement was within one week in 82.60% of the individuals. The MDs associated with MTZ were 69 restless legs syndrome (RLS), 35 tremors, 10 akathisia (AKT), 9 periodic limb MD, 6 dystonia, 4 rapid eye movement sleep behavior disorders, 3 dyskinesia, 2 parkinsonism, and 1 tic, and in the group not clearly identified, 18 restlessness, 15 hyperkinesis, and 1 extrapyramidal symptom. In the literature, the majority of the reports lack important information about the neurological examination. The management should be the MTZ withdrawal, except in RLS that other options are possible. In AKT, the MTZ should not be rechallenge, and if available, the prescription of a benzodiazepine may reduce recovery time.

Latent Iron Deficiency as a Marker of Negative Symptoms in Patients with First-Episode Schizophrenia Spectrum Disorder

Iron deficiency may alter dopaminergic transmission in the brain. This study investigated whether iron metabolism is associated with negative symptoms in patients with first-episode psychosis. The study enrolled 121 patients with first-episode schizophrenia spectrum disorder, whose duration of treatment was 2 months or less. Negative symptoms were measured using the Positive and Negative Syndrome Scale (PANSS) and Clinician-Rated Dimensions of Psychosis Symptom Severity (Dimensional) scale of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Prominent negative symptoms were defined as moderate or severe negative symptoms on the Dimensional scale of the DSM-5. Iron deficiency was defined as a serum ferritin ≤ 20 ng/mL. Patients with iron deficiency were significantly more likely to have prominent negative symptoms (45.2 vs. 22.2%; p = 0.014) and a higher PANSS negative symptoms score (p = 0.046) than those with normal ferritin levels. Patients with prominent negative symptoms had significantly lower ferritin levels (p = 0.025). The significance of these results remained after controlling for the duration of illness and other confounding variables. Our finding of an independent association between iron deficiency and negative symptoms in patients at the very early stage of illness implies that iron dysregulation has an effect on negative symptoms in patients with schizophrenia. The possibility of therapeutic intervention with iron should be further investigated.

Drug-Induced Restless Legs Syndrome

OBJECTIVE

To review the literature on drug-induced restless legs syndrome (DI-RLS).

DATA SOURCES

The review included a search for English-language literature from 1966 to December 2017 in the MEDLINE, PubMed, and Ovid databases using the following search terms: restless legs syndrome (RLS), periodic limb movement, adverse effects, and drug-induced. In addition, background articles on the pathophysiology, etiology, and epidemiology of RLS were retrieved. Bibliographies of relevant articles were reviewed for additional citations.

STUDY SELECTION AND DATA EXTRACTION

All case reports, case series, and review articles of DI-RLS were identified and analyzed. There were only a small number of controlled clinical trials, and most data were from case reports and case series.

RESULTS

Several drugs and drug classes have been implicated in DI-RLS, with antidepressants, antipsychotics, and antiepileptics having the most evidence. In addition, RLS may be linked with a number of disorders or underlying predisposing factors as well.

CONCLUSIONS

The prevalence of RLS is variable and ranges from 3% to 19% in the general population. There are many predisposing factors to RLS, but an emerging body of evidence suggests that there is an association between numerous drugs and RLS.

Medications associated with restless legs syndrome: a case-control study in the US Renal Data System (USRDS)

OBJECTIVE

The objective of this study was to determine the association between the usage of four classes of "at-risk" medications (antidepressants, neuroleptics, antihistamines, and antiemetics with dopamine blockade) and restless legs syndrome (RLS) in dialysis patients within the United States Renal Data System (USRDS).

METHODS

This was a case-control design within a national (United States) patient registry of all patients with end-stage renal disease (ESRD) in the USRDS anytime during the period of 1 October 2006 to 31 December 2010, inclusive. A total of 16,165 ESRD patients (3234 cases; 12,931 age-, sex-, and race-matched controls) were studied.

RESULTS

All four classes of "at-risk" medications see widespread use among patients in the USRDS. All were associated with increased odds of an RLS diagnosis (range of odds ratios, 1.47-2.28; all p < 0.0001) during the period of observation. Results were unchanged when controlling for time on hemodialysis. Usage of more than one class of medication increased the odds for having RLS.

CONCLUSIONS

ESRD patients often receive medication intended for relief of conditions associated with their disease, such as depression and psychological issues, pruritus, and gastroparesis; however, such medications may increase the risk of RLS. Given the high prevalence of RLS in ESRD patients, these medications should only be used when their benefits clearly outweigh the risk of development of the troubling and distressing symptoms of RLS.

Sleep disorders in pregnancy

Sleep disturbances are common in pregnancy and may be influenced by a multitude of factors. Pregnancy physiology may predispose to sleep disruption but may also result in worsening of some underlying sleep disorders, and the de novo development of others. Apart from sleep disordered breathing, the impact of sleep disorders on pregnancy, fetal, and neonatal outcomes is poorly understood. In this article, we review the literature and discuss available data pertaining to the most common sleep disorders in perinatal women. These include restless legs syndrome, insomnia, circadian pattern disturbances, narcolepsy, and sleep-disordered breathing.

Restless legs syndrome induced by quetiapine: report of seven cases and review of the literature

We report on seven cases of restless legs syndrome (RLS) in patients treated with quetiapine. Small doses (50-250 mg at bedtime) provoked RLS in a dose-dependent way. Most patients suffered from an affective disorder and all were treated concomitantly with antidepressants. A search of the literature revealed a further nine cases of RLS concerning quetiapine, also afflicting only patients with affective disorders. Quetiapine seems to carry a special risk for RLS in this sort of patient. Possible causes for this concurrence are discussed.

Mirtazapine provokes periodic leg movements during sleep in young healthy men

STUDY OBJECTIVES

Recent evidence suggests that certain antidepressants are associated with an increase of periodic leg movements (PLMS) that may disturb sleep. So far, this has been shown in patients clinically treated for depression and in cross-sectional studies for various substances, but not mirtazapine. It is unclear whether antidepressants induce the new onset of PLMS or only increase preexisting PLMS, and whether this is a general property of the antidepressant or only seen in depressed patients. We report here the effect of mirtazapine on PLMS in young healthy men.

DESIGN

Open-labeled clinical trial (NCT00878540) including a 3-week preparatory phase with standardized food, physical activity, and sleep-wake behavior, and a 10-day experimental inpatient phase with an adaptation day, 2 baseline days, and 7 days with mirtazapine.

SETTING

Research institute.

PARTICIPANTS

Twelve healthy young (20-25 years) men.

INTERVENTIONS

Seven days of nightly intake (22:00) of 30 mg mirtazapine.

MEASUREMENTS AND RESULTS

Sleep was recorded on 2 drug-free baseline nights, the first 2 drug nights, and the last 2 drug nights. Eight of the 12 subjects showed increased PLMS after the first dose of mirtazapine. Frequency of PLMS was highest on the first drug night and attenuated over the course of the next 6 days. Three subjects reported transient restless legs symptoms.

CONCLUSIONS

Mirtazapine provoked PLMS in 67% of young healthy males. The effect was most pronounced in the first days. The possible role of serotonergic, noradrenergic and histaminergic mechanisms in mirtazapine-induced PLMS is discussed.

Drugs associated with restless legs syndrome: a case/noncase study in the French Pharmacovigilance Database

BACKGROUND

Several case reports have suggested that drugs could induce restless legs syndrome. However, no systematic review of this adverse drug reaction (ADR) in a pharmacovigilance database has been published.

OBJECTIVE

To assess the frequency of restless legs syndrome in the French Pharmacovigilance Database.

METHODS

We selected all ADR reports from January 1, 1984 to December 31, 2009 coded as restless legs syndrome. Restless legs syndrome diagnosis was validated from case descriptions. Using a case/noncase approach, reporting odds ratio and 95% confidence interval were calculated for "suspected'' drugs with 2 or more observations.

RESULTS

Twenty-six ADR reports were found. Four cases were excluded because of alternative diagnosis. Fourteen cases were women (64%). Median age was 57. Most frequently suspected drugs were antidepressants (reporting odds ratio, 15.9 [6.4-39.7]; amitriptyline, escitalopram, mianserine, mirtazapine, duloxetine), neuroleptics (17.8 [6.1-51.7]; thioridazine, loxapine, risperidone, aripiprazole) or tramadol (18.2 [6.3-52.8]).

CONCLUSIONS

Restless legs syndrome is a very rare ADR that was more frequently reported in association with antidepressants, neuroleptics, or tramadol.

The treatment of restless legs syndrome and periodic limb movement disorder in adults--an update for 2012: practice parameters with an evidence-based systematic review and meta-analyses: an American Academy of Sleep Medicine Clinical Practice Guideline

A systematic literature review and meta-analyses (where appropriate) were performed to update the previous AASM practice parameters on the treatments, both dopaminergic and other, of RLS and PLMD. A considerable amount of literature has been published since these previous reviews were performed, necessitating an update of the corresponding practice parameters. Therapies with a STANDARD level of recommendation include pramipexole and ropinirole. Therapies with a GUIDELINE level of recommendation include levodopa with dopa decarboxylase inhibitor, opioids, gabapentin enacarbil, and cabergoline (which has additional caveats for use). Therapies with an OPTION level of recommendation include carbamazepine, gabapentin, pregabalin, clonidine, and for patients with low ferritin levels, iron supplementation. The committee recommends a STANDARD AGAINST the use of pergolide because of the risks of heart valve damage. Therapies for RLS secondary to ESRD, neuropathy, and superficial venous insufficiency are discussed. Lastly, therapies for PLMD are reviewed. However, it should be mentioned that because PLMD therapy typically mimics RLS therapy, the primary focus of this review is therapy for idiopathic RLS.

The psychopharmacological management of RLS in psychiatric conditions: a review of the literature

BACKGROUND

Restless legs syndrome (RLS) is a movement disorder treated with dopamine agonists. RLS is often diagnosed as a comorbid condition with psychiatric disorders, which are treated with dopamine antagonists or antidepressants resulting in onset or exacerbation of RLS symptoms.

OBJECTIVES

The objectives of this article are to provide a review of the literature to (a) describe the comorbidity of psychiatric disorders associated with RLS, (b) identify the treatment of psychiatric disorders that cause or exacerbate symptoms of RLS, and (c) provide clinical recommendations for psychiatric health care providers.

DESIGN

A review of the literature of English articles included the databases of Medline, Pubmed, PsychINFO, and CINAHL for "Restless Legs Syndrome" with major psychiatric disorders including mood disorders (depression and bipolar), schizophrenia, and anxiety disorders (anxiety, panic disorder, obsessive compulsive disorder). The PRISMA guidelines were used to improve the reporting of the review of the literature.

RESULTS

There were 61 articles that met the inclusion and exclusion criteria identified for the review of the literature, including RLS with mood disorders (n = 36), schizophrenia (n = 9), and anxiety disorders (n = 16).

CONCLUSIONS

Clinical trials are lacking on the best treatment for persons with RLS and psychiatric disorders; the most rigorous research found in the literature related to depression and anxiety. Studies lack evidence to document the best practice for persons with RLS and comorbid psychiatric disorders. Psychiatric health care providers should be aware of RLS, which is influenced by psychiatric medications.

Clinically significant drug interactions with newer antidepressants

After the introduction of selective serotonin reuptake inhibitors (SSRIs), other newer antidepressants with different mechanisms of action have been introduced in clinical practice. Because antidepressants are commonly prescribed in combination with other medications used to treat co-morbid psychiatric or somatic disorders, they are likely to be involved in clinically significant drug interactions. This review examines the drug interaction profiles of the following newer antidepressants: escitalopram, venlafaxine, desvenlafaxine, duloxetine, milnacipran, mirtazapine, reboxetine, bupropion, agomelatine and vilazodone. In general, by virtue of a more selective mechanism of action and receptor profile, newer antidepressants carry a relatively low risk for pharmacodynamic drug interactions, at least as compared with first-generation antidepressants, i.e. monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs). On the other hand, they are susceptible to pharmacokinetic drug interactions. All new antidepressants are extensively metabolized in the liver by cytochrome P450 (CYP) isoenzymes, and therefore may be the target of metabolically based drug interactions. Concomitant administration of inhibitors or inducers of the CYP isoenzymes involved in the biotransformation of specific antidepressants may cause changes in their plasma concentrations. However, due to their relatively wide margin of safety, the consequences of such kinetic modifications are usually not clinically relevant. Conversely, some newer antidepressants may cause pharmacokinetic interactions through their ability to inhibit specific CYPs. With regard to this, duloxetine and bupropion are moderate inhibitors of CYP2D6. Therefore, potentially harmful drug interactions may occur when they are coadministered with substrates of these isoforms, especially compounds with a narrow therapeutic index. The other new antidepressants are only weak inhibitors or are not inhibitors of CYP isoforms at usual therapeutic concentrations and are not expected to affect the disposition of concomitantly administered medications. Although drug interactions with newer antidepressants are potentially, but rarely, clinically significant, the use of antidepressants with a more favourable drug interaction profile is advisable. Knowledge of the interaction potential of individual antidepressants is essential for safe prescribing and may help clinicians to predict and eventually avoid certain drug combinations.

Prevalence and clinical correlates of restless legs syndrome among psychogeriatric patients

OBJECTIVE

To evaluate the prevalence, clinical features, and comorbidities of restless legs syndrome (RLS) among psychogeriatric patients in an out-patient clinical setting.

METHODS

Cross-sectional study of a sample of 100 non-demented psychogeriatric outpatients that were assessed for the presence of RLS using the Revised International Restless Legs Syndrome Study Group criteria and other support criteria. Medical and psychiatric illnesses, drug treatments, and other risk factors for RLS were documented.

RESULTS

Prevalence of definite RLS in our sample was 11.11% with an additional prevalence of 10.10% of possible RLS. None of these patients had received a diagnosis of RLS previously. RLS was associated with major depressive disorder and with hypertension, but not with other previously described risk factors as female gender, some medical conditions, or psychoactive drug treatments.

CONCLUSIONS

RLS is a frequent condition in psychogeriatric patients, especially among those with depression, and is commonly underdiagnosed and undertreated. Clinicians should routinely ask for RLS symptoms when assessing their patients in their regular clinical practice.

Management of schizophrenia with obsessive-compulsive features

Although obsessive-compulsive symptoms (OCS) in schizophrenia have been conceptually controversial and clinically challenging, recent evidence suggests that schizophrenia with OCS may constitute a distinct schizophrenic subgroup. Recent epidemiological and clinical findings have shown that the subgroup obsessive-compulsive (OC) schizophrenia is associated with poor outcome and is more frequent than previously realized. Emerging biological evidence suggests that OCS in schizophrenia has more than one pathogenesis, with distinct mechanisms that may require different treatment interventions. Therefore, the management of OCS in patients with schizophrenia requires an individualized treatment approach based on the pathogenesis and clinical status of the patient. For example, the atypical antipsychotics that are potent serotonin antagonists sometimes induce de novo or exacerbate preexisting OCS, which resolves if the patient is switched to an antipsychotic with a different profile or if adjunctive treatment with serotonin reuptake inhibitors (SSRIs) is undergone. Regarding OC schizophrenia, SSRIs are often a necessary part of treatment, with knowledge of potential pharmacokinetic interactions with antipsychotic drugs essential. In this article, recent progress and current knowledge of OC schizophrenia is reviewed and treatment guidelines are offered for this complex and challenging subgroup of schizophrenic patients.