Early extrapyramidal side-effects as risk factors for later tardive dyskinesia: a prospective study

A new era in the diagnosis and treatment of tardive dyskinesia

Tardive dyskinesia (TD) is a heterogeneous, hyperkinetic movement disorder induced by dopamine-receptor blocking agents that presents a unique challenge in the treatment of psychosis. Although acceptance of TD as a serious consequence of antipsychotic treatment was resisted initially, subsequent research by many investigators in psychopharmacology contributed to a rich store of knowledge on many aspects of the disorder. While basic neuroscience investigations continue to deepen our understanding of underlying motor circuitry, past trials of potential treatments of TD focusing on a range of theoretical targets were often inconclusive. Development of newer antipsychotics promised to reduce the risk of TD compared to older drugs, but their improved tolerability unexpectedly enabled an expanding market that paradoxically both increased the absolute number of patients at risk and diminished attention to TD which was relegated to legacy status. Fortunately, development and approval of novel vesicular monoamine transporter inhibitors offered evidence-based symptomatic treatment of TD for the first time and rekindled interest in the disorder. Despite recent progress, many questions remain for future research including the mechanisms underlying TD, genetic predisposition, phenomenological diversity, whether new cases are reversible, how to implement best practices to prevent and treat TD, and whether the development of novel antipsychotics free of the risk of TD is attainable. We owe our patients the aspirational goal of striving for zero prevalence of persistent symptoms of TD in anyone treated for psychosis.

Comparative Tolerability of Dopamine D2/3 Receptor Partial Agonists for Schizophrenia

Aripiprazole, brexpiprazole and cariprazine differ from all other second-generation antipsychotics due to partial agonism at the dopamine D2 and D3 receptors. In contrast to aripiprazole, brexpiprazole has lower intrinsic dopamine D2 activity and higher affinity for the serotonin 5-HT1A and 5-HT2A receptors, while cariprazine has the highest affinity for the dopamine D3 receptor, and the longest half-life. The main adverse effect of dopamine receptor partial agonists (DRPAs) is akathisia of low-to-moderate severity, which occurs in a small proportion of patients, usually in the first few weeks of treatment. While definitive conclusions concerning differences between the DRPAs require head-to-head comparison studies, on the available evidence, akathisia is probably least likely to occur with brexpiprazole and most likely with cariprazine; the risk of akathisia with aripiprazole lies in between. Weight-gain risk is low with aripiprazole and cariprazine, but moderate with brexpiprazole. Risk of sedation is low with DRPAs, as is risk of insomnia and nausea. Partial dopamine agonism leads to a low risk for hyperprolactinaemia (and probably a low risk of sexual dysfunction). Prolactin concentrations fall in some patients (particularly those with elevated levels prior to initiating the drugs). Rates of discontinuation due to adverse effects in pivotal studies were low, and on the whole, DRPAs are well tolerated. Aripiprazole has been implicated in pathological gambling and other impulse control behaviours, likely due to partial dopamine agonist activity (there have been no reports with brexpiprazole and cariprazine). The risks for diabetes and tardive dyskinesia with DRPAs are unknown, but are likely to be low. On the basis of tolerability, DRPAs should be considered as first-line treatment options, particularly in patients with early schizophrenia.

Metabolism of risperidone by CYP2D6 and the presence of drug-induced dopamine supersensitivity psychosis in patients with schizophrenia

High-dose antipsychotic(s) can induce dopamine supersensitivity psychosis in schizophrenia patients. The precise relationship between a drug's blood concentration and the occurrence of dopamine supersensitivity psychosis has not been established. We divided 36 patients with schizophrenia who had undergone treatment mainly with risperidone into two groups: one with normal metabolizing activity of CYP2D6 (n = 15), and the other with lower activity of its variant, CYP2D6*10 (n = 21). The patients' blood concentrations of risperidone and 9-OH-risperidone were measured, and we compared the occurrence of dopamine supersensitivity psychosis episodes between the groups. There was no significant difference in any concentration of risperidone, 9-OH-risperidone, or active moiety between the groups although the with-CYP2D6*10 group had greater variabilities of these parameters compared to the without-CYP2D6*10 group. There was a lower rate of dopamine supersensitivity psychosis episodes in the without-CYP2D6*10 group (4/15, 26.7%) compared to the with-CYP2D6*10 group (11/21, 52.4%), but the difference was not significant. Although our findings were negative, largely because of the small sample size, these results suggest that (1) patients with an impaired functional allele of CYP2D6 may have higher concentrations of risperidone and its active metabolite and that (2) these patients may experience more frequent dopamine supersensitivity psychosis episodes.

Switching antipsychotic treatment to aripiprazole in psychotic patients with neuroleptic-induced tardive dyskinesia: a 24-week follow-up study

Aripiprazole is a second-generation antipsychotics, acting as a partial dopamine D2 receptor agonist. Previous studies on aripiprazole for tardive dyskinesia (TD) treatment were limited and inconclusive. This study was aimed to examine the effectiveness of aripiprazole in psychotic patients with a pre-existing TD. This was an open-label 24-week prospective cohort study conducted in a public mental hospital in Northern Taiwan from January 2009 to February 2010. Psychotic patients were cross-titrated of prior antipsychotics with aripiprazole, and the severity of TD was assessed at baseline and at weeks 2, 4, 8, 12, 16, 20, and 24. The primary study outcome was the change of TD severity, assessed by Abnormal Involuntary Movement Scale (AIMS) total score. Responder was defined as the reduction of AIMS total scores of no less than 50% from baseline to the study endpoint (24 weeks). Thirty psychotic patients with neuroleptic-induced TD were recruited. The AIMS total scores significantly decreased from baseline to the study endpoint (-7.17±5.55). The significant decrease of AIMS total scores started at week 2 (P<0.0001), and the change remained significant throughout the entire study period (P<0.0001). A greater severity of TD (adjusted odds ratio: 1.35, 95% confidence interval: 1.04-1.76, P=0.03) or a lower severity of parkinsonism (adjusted odds ratio: 0.78, 95% confidence interval: 0.61-0.99, P=0.04) at baseline was significantly associated with treatment responders. Our findings implicated that aripiprazole can be a promising treatment for clinicians considering drug switch in psychotic patients with TD. Further large randomized, controlled trials are warranted to confirm our findings.

Clinical risk factors for the development of tardive dyskinesia

BACKGROUND

Tardive dyskinesia (TD) is a severe condition that can affect almost 1 out of 4 patients on current or previous antipsychotic treatment, including both first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs). While two novel vesicular monoamine transporter inhibitors, deutetrabenazine and valbenazine, have shown acute efficacy for TD, the majority of patients do not remit, and TD appears to recur once treatment is withdrawn. Hence, prevention of TD remains a crucial goal.

METHODS

We provide a clinically oriented overview of risk factors for TD, dividing them into patient-, illness- and treatment-related variables, as well as nonmodifiable and modifiable factors.

RESULTS

Unmodifiable patient-related and illness-related risk factors for TD include older age, female sex, white and African descent, longer illness duration, intellectual disability and brain damage, negative symptoms in schizophrenia, mood disorders, cognitive symptoms in mood disorders, and gene polymorphisms involving antipsychotic metabolism and dopamine functioning. Modifiable comorbidity-related and treatment-related factors include diabetes, smoking, and alcohol and substance abuse, FGA vs SGA treatment, higher cumulative and current antipsychotic dose or antipsychotic plasma levels, early parkinsonian side effects, anticholinergic co-treatment, akathisia, and emergent dyskinesia.

DISCUSSION

Clinicians using dopamine antagonists need to consider risk factors for TD to minimize TD and its consequences.

Incidence of tardive dyskinesia in older adult patients treated with olanzapine or conventional antipsychotics

BACKGROUND

The risk of persistent tardive dyskinesia (TD) was compared in patients with acute psychosis or agitation aged 55 years or older who were treated with olanzapine (OLZ) or conventional antipsychotic (CNV) drug therapy.

METHODS

Patients without TD were randomized to treatment with OLZ (2.5-20 mg/d; n = 150) or CNV (dosed per label; n = 143). Following a 6-week drug tapering/initiation period, patients without TD were treated with OLZ or CNV for up to 1 year. The a priori defined primary outcome end point was persistent TD defined as Abnormal Involuntary Movement Scale (AIMS) scores = 2 on at least 2 items or ≥3 on at least 1 item (items 1-7) lasting at least for 1 month (Criterion A). Post hoc analyses assessed persistent TD meeting the criterion of moderate severity defined as AIMS score ≥3 on at least 1 item persisting for 1 month (Criterion B) and probable TD defined as elevated AIMS scores (Criterion A or B) not persisting for 1 month. Treatment groups were compared using Kaplan-Meier curve with log-rank exact test.

RESULTS

On average, patients were 78 years of age; the predominant diagnosis was dementia (76.7% in the OLZ group and 82.5% in the CNV group). Approximately, 40.6% of patients in the CNV group received haloperidol. No significant difference in time to developing persistent TD was observed during treatment with OLZ or CNV (cumulative incidence: OLZ, 2.5% [95% confidence interval [95% CI]: 0.5-7.0]; CNV, 5.5% [95% CI: 2.1-11.6], P = .193). The exposure-adjusted event rates per 100 person-years were not significantly different between treatment groups: OLZ (2.7) and CNV (6.3; ratio: 0.420; 95% CI: 0.068-1.969). Post hoc analyses revealed a significantly lower risk of at least moderately severe persistent TD persisting for 1 month (P = .012) and probable TD not persisting for 1 month (Criterion A, P = .030; Criterion B, P = .048) in OLZ-treated patients. For those patients without significant extrapyramidal symptoms at baseline, significantly more patients in the CNV treatment group developed treatment-emergent parkinsonism than for patients in the OLZ treatment group (CNV: 70%, 35 of 50 patients; OLZ 44%, 25 of 57 patients; P = .011). No significant difference between the groups was observed for treatment-emergent akathisia (CNV: 6%, 7 of 117 patients; OLZ: 10%, 13 of 130 patients; P = .351).

CONCLUSION

The cumulative incidence of persistent TD was low and the risk of persistent TD did not differ significantly among predominantly older adult patients having dementia with acute psychosis or agitation treated with OLZ or CNV.

Prevalence and risk factors associated with tardive dyskinesia among Indian patients with schizophrenia

BACKGROUND

Tardive dyskinesia (TD) is one of the most distressing side effects of antipsychotic treatment. As prevalence studies of TD in Asian population are scarce, a cross-sectional study was performed to assess the frequency of TD in Indian patients with schizophrenia and risk factors of TD.

METHOD

Cross-sectional study of 160 Indian patients fulfilling the DSM-IV TR criteria for schizophrenia and who received antipsychotics for at least one year, were examined with two validated scales for TD. Logistic regression analyses were used to examine the relationship between TD and clinical risk factors.

RESULTS

The frequency of probable TD in the total sample was 26.4%. The logistic regression yielded significant odds ratios between TD and age, intermittent treatment, and total cumulative antipsychotic dose. The difference of TD between SGA and FGA disappeared after adjusting for important co-variables in regression analysis.

CONCLUSION

Indian patients with schizophrenia and long-term antipsychotic treatment have a high risk of TD, and TD is associated with older age, intermittent antipsychotic treatment, and a high total cumulative antipsychotic dose. Our study findings suggest that there is no significant difference between SGAs with regards to the risk of causing TD as compared to FGAs.

DRD2/ANKK1 Taq1A (rs 1800497 C>T) genotypes are associated with susceptibility to second generation antipsychotic-induced akathisia

Although the advent of atypical, second-generation antipsychotics (SGAs) has resulted in reduced likelihood of akathisia, this adverse effect remains a problem. It is known that extrapyramidal adverse effects are associated with increased drug occupancy of the dopamine 2 receptors (DRD2). The A1 allele of the DRD2/ANKK1, rs1800497, is associated with decreased striatal DRD2 density. The aim of this study was to identify whether the A1(T) allele of DRD2/ANKK1 was associated with akathisia (as measured by Barnes Akathisia Rating Scale) in a clinical sample of 234 patients who were treated with antipsychotic drugs. Definite akathisia (a score ≥ 2 in the global clinical assessment of akathisia) was significantly less common in subjects who were prescribed SGAs (16.8%) than those prescribed FGAs (47.6%), p < 0.0001. Overall, 24.1% of A1+ patients (A1A2/A1A1) who were treated with SGAs had akathisia, compared to 10.8% of A1- (thus, A2A2) patients. A1+ patients who were administered SGAs also had higher global clinical assessment of akathisia scores than the A1- subjects (p = 0.01). SGAs maintained their advantage over FGAs regarding akathisia, even in A1+ patients who were treated with SGAs. These results strongly suggested that A1+ variants of the DRD2/ANKK1 Taq1A allele do confer an associated risk for akathisia in patients who were treated with SGAs, and these variants may explain inconsistencies found across prior studies, when comparing FGAs and SGAs.

Efficacy and tolerability of extended release quetiapine fumarate (quetiapine XR) monotherapy in patients with generalised anxiety disorder: an analysis of pooled data from three 8-week placebo-controlled studies

OBJECTIVE

Prospectively planned pooled analysis evaluating efficacy and tolerability of acute quetiapine XR monotherapy in generalised anxiety disorder.

METHODS

Data from three 10-week, randomised, double-blind, placebo-controlled studies of similar design were analysed.

RESULTS

At Week 8, Hamilton Anxiety Rating Scale (HAM-A) total score significantly improved with quetiapine XR: least squares means change -13.31, p < 0.001 (50 mg/day, n = 452), -14.39, p < 0.001 (150 mg/day, n = 673) and -12.50, p < 0.05 (300 mg/day, n = 444) versus -11.30 placebo; significant (p < 0.001, n = 665) improvements versus placebo were observed with each dose at Week 1. Significant improvements versus placebo at Week 8 are as follows: HAM-A psychic symptom subscale, Montgomery-Åsberg Depression Rating Scale total, Pittsburgh Sleep Quality Index global scores for all quetiapine XR doses; HAM-A response and remission rates, HAM-A somatic symptom subscale score, Clinical Global Impression-Severity of Illness total score, % patients with Clinical Global Impression-Improvement score ≤2 with quetiapine XR 50 and 150 mg/day; and Quality of Life Enjoyment and Satisfaction Questionnaire short form % maximum total score with quetiapine XR 150 mg/day. In the quetiapine XR 50, 150 and 300 mg/day and placebo groups, 13.2%, 16.5%, 24.0% and 5.4% of patients discontinued because of an adverse event, and 1.9%, 1.4%, 3.7% and 1.8% of patients experienced clinically significant changes in glucose. The most common adverse events with quetiapine XR included dry mouth, somnolence, sedation and constipation.

CONCLUSION

Quetiapine XR monotherapy reduced the symptoms of generalised anxiety disorder, with improvement from Week 1. Adverse events were consistent with the known tolerability profile of quetiapine.

A randomized, double-blind study of once-daily extended release quetiapine fumarate (quetiapine XR) monotherapy in patients with generalized anxiety disorder

This study evaluated once-daily, extended-release quetiapine fumarate (quetiapine XR) monotherapy in generalized anxiety disorder (GAD). This was a 10-week (8-week active treatment/2-week posttreatment drug-discontinuation/tapering phase), double-blind, randomized, placebo-controlled study (D1448C00009). Primary end point was change from randomization at week 8 in Hamilton Anxiety Rating Scale (HAM-A) total score. Overall, 951 patients with GAD were randomized (quetiapine XR: 50 mg/d, n = 234; 150 mg/d, n = 241; 300 mg/d, n = 241; placebo, n = 235). At week 8, HAM-A total scores significantly (P < 0.001) improved versus placebo (-11.10) with quetiapine XR 50 mg/d (-13.31) and 150 mg/d (-13.54), but not 300 mg/d (-11.87; P = 0.240). At week 1, HAM-A total scores significantly improved versus placebo (-5.94) with quetiapine XR 50 mg/d (-7.47; P < 0.01), 150 mg/d (-8.19; P < 0.001), and 300 mg/d (-7.23; P < 0.01). Versus placebo at week 8, quetiapine XR 50 and 150 mg/d significantly improved HAM-A psychic (P < 0.01 and P < 0.001, respectively) and somatic (P < 0.001; P < 0.01, respectively) cluster scores, HAM-A response (≥ 50% total score reduction; P < 0.05), and Clinical Global Impression-Improvement categorical changes (P < 0.05). For quetiapine XR 150 mg/d, significant (P < 0.05) improvements were seen for HAM-A remission (total score, ≤ 7) and Clinical Global Impression-Severity of Illness scores. For quetiapine XR 300 mg/d, improvements in these secondary variables were not significantly different versus placebo. Pittsburgh Sleep Quality Index global scores improved with all 3 doses (quetiapine: XR 50 mg/d, -4.07 [P < 0.05]; 150 mg/d, -4.38 [P < 0.05]; 300 mg/d, -3.97 [P < 0.05], versus -3.31 with placebo). Adverse events (>10% with quetiapine XR) were dry mouth, somnolence, sedation, dizziness, headache, and fatigue. Quetiapine XR (50/150 mg/d) monotherapy was effective at week 8 in patients with GAD; symptom improvement was seen at week 1 for all doses (50/150/300 mg/d). Safety and tolerability were consistent with the known profile of quetiapine.

A randomised controlled study of risperidone and olanzapine for schizophrenic patients with neuroleptic-induced acute dystonia or parkinsonism

The objective of this study was to compare the effects of risperidone and olanzapine in schizophrenic patients with intolerant extrapyramidal side effects (EPS) on first generation antipsychotics. We conducted an 8-week, rater-blinded, flexible dose study. Seventy patients with schizophrenia, who met the DSM-IV research criteria of having neuroleptic-induced acute dystonia or parkinsonism, were randomly assigned to risperidone or olanzapine group. The primary outcome was a comparison of the incidence of concomitant anticholinergic drugs usage between the groups to manage their acute dystonia and parkinsonism. The average doses of risperidone and olanzapine from baseline to study end point were 1.8-3.5 mg/day and 7.7-11.7 mg/day, respectively. There were no significant differences in demographic data, severity of EPS or psychotic symptoms between the groups at baseline assessment. Patients taking risperidone had significantly higher incidence of using anticholinergic drugs to manage acute dystonia or parkinsonism overall during the study (OR = 5.17, 95%CI = 1.49-17.88, P = 0.013). There was no significant between-group difference in the changing of rating scales of EPS and psychotic symptoms. The results of our study favour olanzapine as a better choice in schizophrenic patients with intolerant EPS. Double-blinded, fixed dose and different ethnical study for EPS-intolerant schizophrenic patients is needed to confirm the results of our study.

Incidence of extrapyramidal symptoms and tardive dyskinesia in schizophrenia: thirty-six-month results from the European schizophrenia outpatient health outcomes study

The incidence of treatment-emergent extrapyramidal symptoms (EPSs) and tardive dyskinesia (TD) in schizophrenic patients, and the clinical characteristics associated with an increased risk of developing EPSs and TD were examined. Patients (N = 7728) in the 3-year, prospective, observational Schizophrenia Outpatient Health Outcomes study were examined according to baseline antipsychotic drug exposure. At baseline, 4893 patients (63.3%) had no EPS, and 6921 (89.6%) had no TD. Extrapyramidal symptoms and TD were assessed separately during follow-up: frequency and time to appearance from Kaplan-Meier survival curves and factors associated with time to appearance using Cox proportional hazard regression models. The cumulative incidence of EPS ranged from 7.7% (olanzapine) to 32.8% (depot typical drugs). Compared with olanzapine, patients taking depot typical drugs, oral typical drugs, risperidone, and amisulpride had a significantly higher risk of developing EPS. Differences from clozapine were marginally significant. High baseline clinical severity was associated with a significantly higher risk of developing EPS. The incidence of TD ranged from 2.8% (olanzapine) to 11.1% (depot typical agent). Compared with olanzapine, patients taking depot typical agents, oral typical agents, and risperidone had a significantly higher risk of developing TD. Baseline factors associated with a significantly higher risk of developing TD were age, EPS, a higher negative Clinical Global Impression score, and presence of gynecomastia. In summary, patients treated with typical antipsychotic agents (oral and depot) and risperidone had a higher risk of developing EPS and TD than patients treated with olanzapine. Higher baseline clinical severity was associated with EPS development, whereas age, presence of EPS, a higher negative Clinical Global Impression score, and presence of gynecomastia were associated with TD development.

Incidence and persistence of tardive dyskinesia and extrapyramidal symptoms in schizophrenia

Although it has been suggested that second-generation antipsychotics (SGA) may reduce the rate of prevalent tardive dyskinesia (TD), little is known about the incidence and outcome of TD in those exposed exclusively to SGA. The incidence and subsequent persistence of TD and extrapyramidal symptoms (EPS) was calculated in a cohort of patients with schizophrenia treated predominantly with SGA. This cohort of more than 10,000 patients with schizophrenia was seen six times over a period of two years. Dichotomous measures of EPS and TD were used to calculate the yearly incidence rates of TD and EPS as well as their subsequent cumulative persistence rate in a subset of 9104 and 6285 patients at risk for TD and EPS, respectively. Of 9104 individuals who did not present with TD at baseline, 138 developed TD, yielding a TD incidence rate of 0.74% (95% CI: 0.62, 0.87) and a subsequent cumulative persistence rate of 80%. Of 6285 individuals without EPS at baseline, 464 developed EPS yielding an incidence rate of 3.7% (95% CI: 3.4, 4.0) and a subsequent cumulative persistence rate of 82%. Incidence rates of TD and EPS may be low in the SGA era. However, once emerged, these disorders prove persistent, suggesting strong moderators effects of underlying predisposing factors.

Incidence of tardive dyskinesia with atypical versus conventional antipsychotic medications: a prospective cohort study

OBJECTIVE

Most previous studies of the incidence of tardive dyskinesia with atypical antipsychotics compared with conventional antipsychotics have not had tardive dyskinesia as their primary focus. The current study aimed to compare the incidence of tardive dyskinesia with atypical vs conventional antipsychotics using methods similar to those from a previous prospective cohort study at our site in the 1980s.

METHOD

Three hundred fifty-two initially tardive dyskinesia-free psychiatric outpatients (diagnosed at baseline using the Structured Clinical Interview for DSM-IV) were examined for a new diagnosis of tardive dyskinesia (using the Abnormal Involuntary Movement Scale and Glazer-Morgenstern criteria) every 6 months for up to 4 years at a community mental health center. At baseline, subjects were receiving conventional antipsychotics only (23%), atypicals only (64%), or both (14%). Only 26 subjects had never received conventional antipsychotics. Baseline evaluations were conducted from November 2000 through May 2003. Follow-ups were conducted through February 2005.

RESULTS

Compared with subjects treated with conventional antipsychotics alone since the previous visit, the adjusted tardive dyskinesia incidence rate-ratio for subjects treated with atypical antipsychotics alone was 0.68 (95% CI, 0.29-1.64). The incidence and prevalence of tardive dyskinesia was similar to previous findings at this site in the 1980s.

CONCLUSIONS

The incidence of tardive dyskinesia with recent exposure to atypical antipsychotics alone was more similar to that for conventional antipsychotics than in most previous studies. Despite high penetration of atypical antipsychotics into clinical practice, the incidence and prevalence of tardive dyskinesia appeared relatively unchanged since the 1980s. Clinicians should continue to monitor for tardive dyskinesia, and researchers should continue to pursue efforts to treat or prevent it.

NonParkinsonism Movement Disorders in the Elderly

OBJECTIVE

The primary objective of this article is to review the clinical presentation and pharmacologic management of essential tremor and tardive dyskinesia.

DATA SOURCES

The MEDLINE (1966-August 2005), Cochrane Database of Systematic Reviews, and International Pharmaceutical Abstracts (1970-August 2005) databases were searched for original research and review articles published in English. The search terms were essential tremor and tardive dyskinesia. Reference lists from articles were also consulted.

DATA SYNTHESIS

Essential tremor is most commonly manifested as a postural or action tremor of the upper extremities. Midline regions such as the head and voice are also commonly affected. Based on review of the literature, propranolol and primidone are the current pharmacologic mainstays for treating essential tremor of the upper extremities. The choice of agent depends on patient-specific factors such as underlying medical conditions. Other agents with demonstrated efficacy include gabapentin and topiramate. Benzodiazepines are effective adjunctive agents, but should be utilized judiciously in the elderly. Botulinum toxin is effective for essential tremor of the voice and head. Surgery is very effective, but may not be appropriate in the frail elderly and should be avoided in the presence of cognitive impairment. Tardive dyskinesia is characterized by involuntary choreoathetoid movements of the orofacial region. For the management of tardive dyskinesia, emphasis is placed on primary prevention and early recognition of signs and symptoms. In some cases, discontinuation of the offending agent can result in reversal of symptoms. If a conventional neuroleptic is the causative agent, switching to an atypical antipsychotic may be helpful. Overall, few treatments have proven to be consistently useful. Other agents that may be helpful include acetylcholinesterase inhibitors, amantadine, baclofen, benzodiazepines, branched chain amino acids, gabapentin, levetiracetam, pyridoxine, verapamil, and vitamin E.

CONCLUSION

Current pharmacologic agents for essential tremor can be expected to provide partial benefit. However, agents for the symptomatic management of tardive dyskinesia are limited, and additional research is warranted in this area.

Pharmacogenetic testing in schizophrenia and posttraumatic stress disorder

Genotyping patients prior to beginning psychiatric pharmacological therapy can serve to inform practitioners as to each patient's likelihood of therapeutic response and their relative risk of experiencing toxicity and other adverse side effects from certain drugs. Such information could arm physicians with the knowledge they need to make appropriate drug and dosing decisions and avoid the lengthy trial-and-error process with which they are faced today. This article describes the current state of pharmacogenetic testing in schizophrenia and posttraumatic stress disorder.

Worsening of psychosis in schizophrenia is longitudinally associated with tardive dyskinesia in the European Schizophrenia Outpatient Health Outcomes study

OBJECTIVE

The objective of the study was to examine if worsening of psychosis predicts the emergence of tardive dyskinesia (TD).

METHOD

Global measures of TD and Clinical Global Impression (CGI) overall symptom severity score were rated in 4 assessments in 12 months. In a risk set free of TD at baseline, associations between TD onset and change in CGI scores were assessed using Cox proportional hazard regression.

RESULTS

A total of 8,620 patients yielded 23,565 follow-up observations, 8.8% of which represented a worsening in CGI overall symptom severity relative to the previous observation, yielding an incidence of TD of 5.2%, compared with 2.7% in observations without worsening of psychopathology (rate ratio, 1.9; 95% confidence interval, 1.3-2.7). Incidence of TD was longitudinally associated with a worsening of the CGI overall symptom severity in the months preceding TD onset (adjusted hazard ratio over 6 levels of CGI score, 1.3; 95% confidence interval, 1.1-1.4).

CONCLUSION

Worsening in overall psychopathology in schizophrenia is longitudinally associated with the emergence of TD as measured by CGI overall symptom severity.

Predictors of neuroleptic-induced dyskinesia and parkinsonism: the influence of measurement methods and definitions

The accurate and objective measurement of abnormal, involuntary movements remains highly desirable, whether the movements are secondary to pharmacotherapy or an expression of the primary illness. In a previous study, we found that the prevalence of tardive dyskinesia in a sample of 100 subjects ranged from 28% when using the Abnormal Involuntary Movement Scale (AIMS) or the Dyskinesia Identification Scale, Condensed User Version (DISCUS) to 62% using an instrumental measurement (IM) of peripheral dyskinesia. The goal of this study was to examine the relationship between various risk factors for tardive dyskinesia as predictor variables, and the AIMS, DISCUS, and IMs of dyskinesia, tremor, and velocity of motor movement as dependent variables. The sample consisted of 100, mostly patients with schizophrenia. Poor performance on the Mini-Mental State Examination (MMSE) and increasing age were the most consistent predictors of dyskinetic and parkinsonian movements. Various predictors were associated with specific abnormal movements. Head injury was related to slower speed of motor movements and the total DISCUS score. A history of smoking was associated with less IM dyskinesia. For those with coexisting parkinsonism and dyskinesia, significant associations were found with head injury, diabetes mellitus, and an AIMS score of 2 or greater in 2 body areas. Various classes of psychotropic agents seemed to have little influence on the MMSE or the development of dyskinesia and parkinsonism. Increasing age and a lower score on the MMSE seem to be particularly helpful in gauging the risk for parkinsonian and dyskinetic movements.

Risperidone for pre-existing severe tardive dyskinesia: a 48-week prospective follow-up study

Atypical antipsychotics can alleviate the severity of tardive dyskinesia, but few studies have monitored their long-term effects. The present study investigated the effect of risperidone on pre-existing severe tardive dyskinesia among 40 patients with chronic schizophrenia over 48 weeks. The total Abnormal Involuntary Movement Scale (AIMS) score decreased in 35 patients (87.5%) and increased in three patients (7.5%). At the end of the 48-week trial, the mean total AIMS score decreased significantly, from 15.7+/-4.7 (baseline) to 10.6+/-4.4 (P<0.001), with a mean risperidone dosage of 3.6+/-1.5 mg/day. Twenty-three patients (57.5%) were responders with an average total AIMS score decrease of 8.0+/-2.7. Multiple logistic regression analysis controlling for age, gender, duration of illness, index hospitalization duration, risperidone dose, anticholinergic concomitant use and dystonia score change revealed that a change in the parkinsonism score was the most significant factor related to responders (odds ratio 3.476, 95% confidence interval 1.173-10.298). A significant improvement observed in tardive dyskinesia was noted at week 8, and this improvement persisted until week 48. The results show that the effect of risperidone on pre-existing tardive dyskinesia may be beneficial.