A case of tetrabenazine-induced neuroleptic malignant syndrome after prolonged treatment

Risk of Neuroleptic Malignant Syndrome with Vesicular Monoamine Transporter Inhibitors

Objective

Vesicular monoamine transporter-2 (VMAT2) inhibitors have been proven to be effective for the treatment of tardive dyskinesia and their use is likely to increase. The evidence base of published clinical reports was reviewed to evaluate the possible risk of neuroleptic malignant syndrome (NMS) with these drugs.

Methods

Pubmed, Embase, Web of Science and PsycINFO databases were queried for all years using terms for “neuroleptic malignant syndrome”, “hyperthermia” AND “vesicular monoamine transporter inhibitors”, “reserpine”, “tetrabenazine”, “valbenazine” or “deutetrabenazine”

Results

Thirteen clinical cases, ten of which involved tetrabenazine, were identified in which VMAT2 inhibitors were prescribed in patients with current or past NMS episodes. In most cases, the association was confounded by limited reporting of clinical data, variable temporal correlation with VMAT2 inhibitors, polypharmacy with antipsychotics, and uncertain differential diagnoses.

Conclusion

While rare cases of NMS meeting consensus criteria have been reported primarily with tetrabenazine, the risk with recently developed VMAT2 inhibitors may be even less. Evidence of causality of NMS with VMAT2 inhibitors is confounded by concomitant treatment with antipsychotics and diagnostic uncertainties in patients susceptible to basal ganglia dysfunction. Nevertheless, clinicians should remain vigilant for early signs of NMS in all patients treated with any drugs that affect brain dopamine activity.

Acute Dystonic Reaction and the Neuroleptic Malignant Syndrome

Up to 90% of patients on chronic antipsychotic therapy will experience adverse neurologic side effects, with many of these effects attributable to the dopamine-blocking properties of these drugs. Even the newer, “atypical” antipsychotics are increasingly associated with neurologic complications. In the acute care setting, these medications have broad application beyond the management of psychiatric illness. Given the extent of their use, clinicians should be familiar with the spectrum of neurological syndromes that can develop. Some are common, such as akathisia, acute dystonic reaction, tardive dyskinesia, and drug-induced parkinsonism. Others, such as the life-threatening neuroleptic malignant syndrome, are rare yet must be recognized early to affect survival and improve outcome. This discussion highlights 2 idiosyncratic syndromes, acute dystonic reaction and neuroleptic malignant syndrome. The differential diagnosis for both syndromes and their management is discussed.

Neuroleptic malignant syndrome induced by combination therapy with tetrabenazine and tiapride in a Japanese patient with Huntington's disease at the terminal stage of recurrent breast cancer

We herein describe the case of an 81-year-old Japanese woman with neuroleptic malignant syndrome that occurred 36 days after the initiation of combination therapy with tiapride (75 mg/day) and tetrabenazine (12.5 mg/day) for Huntington's disease. The patient had been treated with tiapride or tetrabenazine alone without any adverse effects before the administration of the combination therapy. She also had advanced breast cancer when the combination therapy was initiated. To the best of our knowledge, the occurrence of neuroleptic malignant syndrome due to combination therapy with tetrabenazine and tiapride has not been previously reported. Tetrabenazine should be administered very carefully in combination with other neuroleptic drugs, particularly in patients with a worsening general condition.

Neuroleptic malignant syndrome: a review for neurohospitalists

Neuroleptic malignant syndrome (NMS) is a life-threatening idiosyncratic reaction to antipsychotic drugs characterized by fever, altered mental status, muscle rigidity, and autonomic dysfunction. It has been associated with virtually all neuroleptics, including newer atypical antipsychotics, as well as a variety of other medications that affect central dopaminergic neurotransmission. Although uncommon, NMS remains a critical consideration in the differential diagnosis of patients presenting with fever and mental status changes because it requires prompt recognition to prevent significant morbidity and death. Treatment includes immediately stopping the offending agent and implementing supportive measures, as well as pharmacological interventions in more severe cases. Maintaining vigilant awareness of the clinical features of NMS to diagnose and treat the disorder early, however, remains the most important strategy by which physicians can keep mortality rates low and improve patient outcomes.

Tetrabenazine for the treatment of tardive dyskinesia

OBJECTIVE

To evaluate the safety and effectiveness of tetrabenazine for the treatment of tardive dyskinesia.

DATA SOURCES

Literature was accessed through MEDLINE (1966-September 2010) and The Cochrane Library using the terms tetrabenazine, tardive dyskinesia, and movement disorders. In addition, references from publications identified were reviewed.

STUDY SELECTION AND DATA EXTRACTION

All English-language articles identified from the data sources were reviewed.

DATA SYNTHESIS

Options available for the management of tardive dyskinesia are limited. Tetrabenazine is a central monoamine-depleting agent approved by the Food and Drug Administration for chorea associated with Huntington's disease. Three prospective studies of tetrabenazine in the treatment of tardive dyskinesia were identified, as well as 8 additional trials, 1 case series, and 8 case reports. Tetrabenazine may provide benefit in managing symptoms of tardive dyskinesia unresponsive to other treatment modalities. Treatment of tardive dyskinesia with tetrabenazine may be limited by cost and clinically significant adverse effects such as depression, parkinsonism, and somnolence.

CONCLUSIONS

Small trials indicate tetrabenazine may be effective for the treatment of tardive dyskinesia. However, larger, well-conducted trials are needed to confirm these findings. Currently, there is a lack of data coupled with the risk of significant adverse effects to recommend the routine use of tetrabenazine in the management of tardive dyskinesia. Before using tetrabenazine for the management of tardive dyskinesia, all other options should be exhausted and careful monitoring employed.

Neuroleptic malignant syndrome: mechanisms, interactions, and causality

This review focuses on new data from recent publications concerning how compounding interactions between different thermoregulatory pathways influence the development of hyperthermia and/or neuroleptic malignant syndrome (NMS), and the fundamental issue of the presumed causal role of antipsychotic drugs. The formal criteria for substantiating cause-effect relationships in medical science, established by Hill, are applied to NMS and, for comparison, also to malignant hyperthermia and serotonin toxicity. The risk of morbidities related to hyperthermia is reviewed from human and experimental data: temperatures in excess of 39.5°C cause physiological and cellular dysfunction and high mortality. The most temperature-sensitive elements of neural cells are mitochondrial and plasma membranes, in which irreversible changes occur around 40°C. Temperatures of up to 39°C are "normal" in mammals, so, the term hyperthermia should be reserved for temperatures of 39.5°C or greater. The implicitly accepted presumption that NMS is a hypermetabolic and hyperthermic syndrome is questionable and does not explain the extensive morbidity in the majority of cases, where the temperature is less than 39°C. The thermoregulatory effects of dopamine and acetylcholine are outlined, especially because they are probably the main pathways by which neuroleptic drugs might affect thermoregulation. It is notable that even potent antagonism of these mechanisms rarely causes temperature elevation and that multiple mechanisms, including the acute phase response, stress-induced hyperthermia, drugs effects, etc., involving compounding interactions, are required to precipitate hyperthermia. The application of the Hill criteria clearly supports causality for drugs inducing both MH and ST but do not support causality for NMS.

Tetrabenazine

BACKGROUND

Tetrabenazine (TBZ) depletes presynaptic dopamine in the CNS. It has been found to be beneficial in hyperkinetic movement disorders without carrying the extrapyramidal side effects that are characteristic of neuroleptics.

OBJECTIVE

To summarize current knowledge on the use of TBZ and draw conclusions about its efficacy and safety.

METHODS

PubMed literature searches using the term 'tetrabenazine' were carried out for the period prior to May 2009. Additional relevant studies referenced by these publications were included.

CONCLUSIONS

Both short- and long-term studies have consistently yielded favorable results for the use of TBZ in the treatment of hyperkinetic movement in terms of efficacy and safety. TBZ is most effective in reducing chorea (including Huntington's disease associated chorea), tic associated with Tourette's syndrome and tardive dyskinesias. Furthermore, TBZ might also have potential for use in other hyperkinetic disorders (e.g., myoclonus and dystonia), for which future clinical trials are needed.

The management of tics

A tic is a stereotyped repetitive involuntary movement or sound, frequently preceded by premonitory sensations or urges. Most tic disorders are genetic or idiopathic in nature, possibly due to a developmental failure of inhibitory function within frontal-subcortical circuits modulating volitional movements. Currently available oral medications can reduce the severity of tics, but rarely eliminate them. Botulinum toxin injections can be effective if there are a few particularly disabling motor tics. Deep brain stimulation has been reported to be an effective treatment for the most severe cases, but remains unproven. A comprehensive evaluation accounting for secondary causes, psychosocial factors, and comorbid neuropsychiatric conditions is essential to successful treatment of tic disorders.

The current clinical management of Huntington's disease

Huntington's disease is a neurodegenerative condition, characterized by movement disorders, cognitive decline, and psychiatric disturbance. We review the pharmacological management of the various movement disorders associated with the disease, the cognitive decline and the commonly encountered behavioral disturbances. We discuss the nonclassical features of the disease, important in the management of these patients. Nonpharmacological support including genetic counseling and therapy and the importance of palliative care are also addressed. Finally, experimental approaches that may soon impact upon clinical practice are discussed.

Tourette's syndrome and role of tetrabenazine: review and personal experience

Gilles de la Tourette's syndrome (Tourette's syndrome; TS) is an inherited tic disorder commonly associated with other neurobehavioural conditions such as attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). While the clinical presentation of TS and other features of this disorder have been well characterized, the genetic and neurobiological basis of the disease remains incompletely elucidated. The suggestion of a central role of dopamine in the aetiology of TS has been made on the basis of experimental studies, evidence from neuroimaging studies and the therapeutic response patients with TS have to agents that antagonize or interfere with putative dopaminergic pathways. Tetrabenazine is such an agent; it depletes presynaptic dopamine and serotonin stores and blocks postsynaptic dopamine receptors. In clinical studies, tetrabenazine has been found to be effective in a wide range of hyperkinetic movement disorders, including small numbers (<50) of patients with TS in some studies. Results of a retrospective chart review enrolling only patients with TS (n = 77; mean age approximately 15 years) showed that 2 years' treatment with tetrabenazine resulted in an improvement in functioning and TS-related symptoms in over 80% of patients, findings that suggest that treatment with tetrabenazine may have long-term benefits. The authors' experience with 120 heavily co-medicated patients with TS confirms these findings. Long-term (mean 19 months) tetrabenazine treatment resulted in a Clinical Global Impressions of Change scale rating of 'improved' in 76% of patients. Such findings are promising and suggest that tetrabenazine may be suitable as add-on therapy in patients for whom additional suppression of tics is required.

Long-term tolerability of tetrabenazine in the treatment of hyperkinetic movement disorders

We sought to review the long-term tolerability of tetrabenazine (TBZ) and seek determinants of tolerability in the treatment of hyperkinetic movement disorders. A retrospective chart review was performed on patients treated with TBZ between 1997 and 2004. Efficacy of TBZ was assessed by a 1- to 5-point response scale (1 = marked reduction in abnormal movements, 5 = worsening). All adverse events (AEs) were captured according to their relationship with study drug. A total of 448 patients (42% male) were treated for a variety of hyperkinesias, including tardive dyskinesia (n = 149), dystonia (n = 132), chorea (n = 98), tics (n = 92), and myoclonus (n = 19). The mean age at onset of the movement disorder was 43.0 +/- 24.2 years, with TBZ starting at a mean age of 50.0 +/- 22.3 years. Patients remained on treatment for a mean of 2.3 +/- 3.4 years. An efficacy response rating of 1 or 2 was sustained in the majority of patients between the first and last visit. Common AEs included drowsiness (25.0%), Parkinsonism (15.4%), depression (7.6%), and akathisia (7.6%). Comparison of log-likelihood ratios revealed that age was a reliable predictor of Parkinsonism (P < 0.0001). TBZ is a safe and effective drug for the long-term treatment of hyperkinetic movement disorders.

Is history of depression a contraindication to treatment with tetrabenazine?

OBJECTIVE

To determine whether a history of depression predisposes hyperkinetic patients treated with tetrabenazine (TBZ) to a recurrence or worsening of this symptom.

METHODS

We retrospectively reviewed the charts of 518 patients treated with TBZ to determine the frequency of depression and other adverse events. Charts were screened for the preexistence, development, or exacerbation of depression during the course of treatment.

RESULTS

The most common adverse events related to TBZ were somnolence (27.4%), depression (15.1%), parkinsonism (11.8%), and akathisia (8.9%); 78 patients (15.1%) experienced depression for the first time or an exacerbation of existing depression. Of those patients with no history of depression, 28 (11.4%) of 246 were newly diagnosed with depression. Patients with a documented history of depression experienced a significantly higher rate of worsening in 50 (18.4%) of 272 cases (P = 0.03). However, patients with a history of depression experienced more improvement of their hyperkinesia compared to those without a history of depression (P < 0.01).

CONCLUSIONS

Depression, an adverse event of TBZ, is more likely to occur or worsen in patients with a preexisting history of depression.

Tetrabenazine in the treatment of hyperkinetic movement disorders

Tetrabenazine, a dopamine-depleting agent first synthesized half a century ago, was initially developed for the treatment of schizophrenia. Although psychotic disorders have since been treated more successfully with other neuroleptic medications, many studies have shown this drug to be effective in the treatment of hyperkinetic movement disorders (hyperkinesias). Hyperkinesias are neurologic disorders characterized by abnormal involuntary movements such as chorea associated with Huntington's disease, tics in Tourette's syndrome and stereotypies in tardive dyskinesia. Recently, clinical trials investigating tetrabenazine for the treatment of chorea associated with Huntington's disease found the drug to be safe and efficacious, making approval by the US Food and Drug Administration for this indication a distinct possibility.

Tetrabenazine Treatment in Movement Disorders

Tetrabenazine (TBZ) is a catecholamine depletor used for the treatment of a variety of movement disorders. The purpose of this study was to assess the efficacy of TBZ in a retrospective chart review in 3 tertiary care movement disorders centers over long-term treatment. Of 150 patients to whom TBZ was prescribed, 118 were followed up and assessed using the Clinical Global Impression of Change (CGIC), (-3 to +3), a composite grade from a patient and caregiver scale over variable periods. The patients had a variety of hyperkinetic movement disorders including dystonia (generalized and focal: axial, Meige syndrome, torticollis, blepharospasm, bruxism), Huntington disease (HD) or other choreas, tardive dyskinesia (TD) or akathisia, and Tourette syndrome. Mean patient age was 48.8 +/- 18.7 years; 48 were men (40.7%) with a mean disease duration of 93 months. The mean follow-up time was 22 months and the mean TBZ dose was 76.2 +/- 22.5 mg/d (median 75 mg, range 25-175 mg/d). The mean CGIC score was +1 (mild improvement). The group of patients who scored +3 on the CGIC (very good improvement) represented 18.6% (n = 22) of all patients. They had HD or other types of chorea 7.6% (n = 9), facial dystonia/dyskinesia (n = 7, 5.9%), 1 with TD, 2 with trunk dystonia, 2 with Tourette syndrome, and 1 with tardive akathisia. This group had the longest treatment duration and received a mean TBZ dose of 70.5 mg/d (median 75 mg/d) for a mean of 25.4 +/- 21.3 months. The report concludes that TBZ is a moderately effective treatment of a large variety of hyperkinetic movement disorders, with excellent effects in a subgroup with chorea and facial dystonia/dyskinesias.

Tetrabenazine in the treatment of severe pediatric chorea

Tetrabenazine (TBZ) is widely used to treat adults with hyperkinetic movement disorders; however, published experience with the drug in pediatric patients is limited. We report on 5 children with severe chorea who were treated with TBZ. TBZ effectively controlled chorea in 4 patients, and despite the need for relatively high doses, it was well tolerated.

Tetrabenazine treatment for tardive dyskinesia: assessment by randomized videotape protocol

OBJECTIVE

Tetrabenazine, a monoamine depleter and dopamine receptor blocker, is used to treat several hyperkinetic movement disorders. The authors studied the use of tetrabenazine for tardive dyskinesia.

METHOD

Twenty patients with tardive dyskinesia (mean duration = 43.7 months) were videotaped before and after tetrabenazine treatment. Randomized videotapes were scored with the motor subset of the modified Abnormal Involuntary Movement Scale (AIMS) by raters blind to pre- or posttreatment status.

RESULTS

One patient did not tolerate tetrabenazine owing to sedation. The remaining 19 were rated after a mean of 20.3 weeks at a mean tetrabenazine dose of 57.9 mg/day. There were significant improvements in mean scores on both the patient AIMS self-rating and the AIMS motor subset evaluated by the blind videotape raters. All 19 patients continued to take tetrabenazine after the study.

CONCLUSIONS

Tetrabenazine was well tolerated and resulted in significant improvements in AIMS scores for patients with refractory tardive dyskinesia.

Severe hyperthermia during tetrabenazine therapy for tardive dyskinesia

We recently observed a 45-year-old patient with a history of psychiatric illness who presented with severe hyperthermia (rectal temperature above 41 degrees C) with intense rhabdomyolysis and liver cytolysis during tetrabenazine therapy for neuroleptic tardive dyskinesia. In addition to tetrabenazine, this patient took lorazepam and two antidepressant drugs: clomipramine, a potent serotonin-reuptake inhibitor, and mianserin. Hyperthermia responded to parenteral sodium dantrolene and oral bromocriptine administration. The significant role of tetrabenazine (a central nervous system dopamine-depleting drug) and the contribution of antidepressants to the mechanism of this neuroleptic malignant syndrome - like hyperthermia are discussed.