Acute dystonia due to clozapine

[Antipsychotic-induced motor symptoms in schizophrenic psychoses-Part 1 : Dystonia, akathisia und parkinsonism]

Acute antipsychotic-induced movement disorders (AIMD) are clinically relevant since they are frequently associated with high subjective distress, and since over the long-term they can negatively impact treatment adherence of patients with schizophrenic psychoses. This review article summarizes the relevant studies on the prevalence, risk factors, prevention and treatment options and instruments for early prediction of acute AIMD in schizophrenic psychoses. The current evidence and treatment recommendations are divided into three main areas: acute dystonia, akathisia, and parkinsonism. For the treatment of acute dystonia trihexyphenidyl and biperiden have shown their efficacy. Considering pharmacological treatment of akathisia, there is some preliminary evidence for medication with lipophilic beta-receptor blockers (propranolol and pindolol), clonidine, benzodiazepines, mianserin, mirtazapine und trazodone. The treatment options for drug-induced parkinsonism include reduction or switching from one antipsychotic to another with a lower affinity for dopamine D₂ receptors, amantadine or in the regular administration of anticholinergic drugs. In conclusion, acute AIMD is easily to recognize but is not always effectively and durably treated. Early recognition and treatment of acute AIMD could be associated with improved treatment outcomes.

Diagnosis and management of acute movement disorders

Most movement disorders, reflecting degenerative disorders, develop in a slowly progressive fashion. Some movement disorders, however, manifest with an acute onset. We wish to give an overview of the management and therapy of those acute-onset movement disorders.Drug-induced movement disorders are mainly caused by dopamine-receptor blockers (DRB) as used as antipsychotics (neuroleptics) and antiemetics. Acute dystonic reactions usually occur within the first four days of treatment. Typically, cranial pharyngeal and cervical muscles are affected. Anticholinergics produce a prompt relief. Akathisia is characterized by an often exceedingly bothersome feeling of restlessness and the inability to remain still. It is a common side effect of DRB and occurs within few days after their initiation. It subsides when DRB are ceased. Neuroleptic Malignant Syndrome is a rare, but life-threatening adverse reaction to DRB which may occur at any time during DRB application. It is characterised by hyperthermia, rigidity, reduced consciousness and autonomic failure. Therapeutically immediate DRB withdrawal is crucial. Additional dantrolene or bromocriptine application together with symptomatic treatment may be necessary. Paroxysmal dyskinesias are childhood onset disorders characterised by dystonic postures, chorea, athetosis and ballism occurring at irregular intervals. In Paroxysmal Kinesigenic Dyskinesia they are triggered by rapid movements, startle reactions or hyperventilation. They last up to 5 minutes, occur up to 100 times per day and are highly sensitive to anticonvulsants. In Paroxysmal Non-Kinesiogenic Dyskinesia they cannot be triggered, occur less frequently and last longer. Other paroxysmal dyskinesias include hypnogenic paroxysmal dyskinesias, paroxysmal exertional dyskinesia, infantile paroxysmal dystonias, Sandifer's syndrome and symptomatic paroxysmal dyskinesias. In Hereditary Episodic Ataxia Type 1 attacks of ataxia last for up to two minutes, may be accompanied by dysarthria and dystonia and usually respond to phenytoin. In Type 2 they can last for several hours, may be accompanied by vertigo, headache and malaise and usually respond to acetazolamide. Symptomatic episodic ataxias can occur in a number of metabolic disorders, but also in multiple sclerosis and Behcet's disease.

Atypical antipsychotics in the treatment of drug-induced psychosis in Parkinson's disease

Our experience with atypical antipsychotics in patients with PD is that their motor effects are not predictable. The multiple reports concerning clozapine's beneficial effects on tremor, dystonia, nocturnal akathisia, and dyskinesias all underscore this observation. However, the appearance of even minor degrees of parkinsonism in normal volunteers or schizophrenics should suggest that an antipsychotic will not be well-tolerated in patients with PD. The treatment of PD is probably the most stringent test of a drug's freedom from parkinsonian side effects. The data from trials in schizophrenia concerning parkinsonian effects cannot always be confidently interpreted. Virtually all subjects in these trials have been treated with typical neuroleptics until shortly before study entry. Because the parkinsonian side effects of these drugs may persist for several months, patients may still show declining levels of parkinsonism even when placed on a drug that induces it if this effect is milder than that induced by the pre-study neuroleptic. Depending on the pre-study drug used and the duration of the study, distinguishing placebo from a low-potency neuroleptic may be impossible. Furthermore, the standard measure of parkinsonism in psychiatric studies is the Simpson-Angus scale which is heavily weighted toward rigidity and may underscore bradykinesia, gait, and posture abnormalities. The prolactin response to an antipsychotic drug may turn out to be a good predictor of its freedom from parkinsonian side effects. That would fit with the data presented above of clozapine and quetiapine having less parkinsonian effects, olanzapine having more but variable effects and risperidone being poorly tolerated. With the data presented above, comprising a current review of all reports of the use of atypical antipsychotics in PD that we could locate, we can say little with certainty. The only drug with confirmed benefit without worsening parkinsonism is clozapine. Open-label trials involving over 400 patients and two multicenter, placebo-controlled, double-blind trials have demonstrated that it is effective in treating the psychosis. It improves tremor, does not worsen other motor functions to any significant extent, and is safe at low doses. Limited data provide conflicting information on both risperidone and olanzapine. Quetiapine seems to be well-tolerated with some, but definitely less, worsening of PD motor features than risperidone and olanzapine. Based on the current literature, our personal experience, and anecdotal experience of other PD specialists which we solicited, we will venture our own interpretation and recommendations. We think risperidone is poorly tolerated and should be used only as a last resort; that olanzapine is better than risperidone but will, in a majority of patients with PD, worsen motor function. We are optimistic, but not yet convinced, that quetiapine may prove to be as effective and better tolerated than clozapine. It will not require cumbersome monitoring because it does not induce a blood dyscrasia. We therefore recommend that DP be treated in the following manner. First, the anti-PD medications should be simplified and reduced as much as tolerated. We think, in general, side effects multiply more with increasing numbers of drugs than with drug dose, so that patients are more likely to tolerate a higher dose of levodopa than a lower dose of levodopa combined with other adjunctive anti-PD medications. In reducing anti-PD medications, we recommend tapering and stopping, if necessary, the drugs with the highest risk-to-benefit ratio first. Anticholinergics are stopped first, then selegiline, dopamine agonists, amantadine, and finally COMT inhibitors, which have no psychotomimetic action of their own. Finally, levodopa is reduced. Generally, a point is reached at which the anti-PD medications cannot be reduced without jeopardizing motor function. If psychosis persists at this point, then an antipsychotic is added. (ABS

Emerging roles for novel antipsychotic medications in the treatment of schizophrenia

Antipsychotic medications are the mainstay of treatment for schizophrenia. The recent advent of atypical antipsychotics has provided new clinical options and set higher expectations for the treatment of schizophrenia. It is not yet clear how each different drug will fit within the therapeutic armamentarium and this lack is most evident with considering patients with treatment refractory schizophrenia. On the other hand, the expectation of superior efficacy, more benign side effect profile and potential to impact the longitudinal course of schizophrenia provide a rationale for the use of novel antipsychotics as a first-line treatment of schizophrenia.

The emerging role of clozapine in the treatment of movement disorders

Clozapine, the only commercially available atypical neuroleptic, is approved for the treatment of schizophrenic patients who are unresponsive to or intolerant of typical neuroleptics. It has an unusual pharmacologic profile compared with standard neuroleptics, and it follows that clinical response to this drug is also different. It has shattered the notion that a drug must be capable of inducing or worsening parkinsonism to be a potent antipsychotic. Based on these findings, it is being used increasingly by neurologists for psychiatric and nonpsychiatric problems in patients with movement disorders. The most common use for clozapine among neurologists is in the management of drug-induced psychosis in Parkinson's disease (PD). This problem has been a source of increased morbidity and mortality in PD because of a lack of adequate therapeutic intervention. At this time, because of success in numerous open trials, with improvement of > 80% of patients, clozapine therapy for psychosis in PD is becoming the standard of care. It also appears to be of value in the management of some motor features of PD, including tremors and dyskinesia and possibly even sensory symptoms such as akathisia and pain. The literature also suggests that clozapine may be of potential benefit in hyperkinetic movement disorders including essential tremor, Huntington's disease, and tardive dyskinesia. We review the current data concerning the use of clozapine in patients with these movement disorders and others.

Neuroleptic binding to sigma receptors: possible involvement in neuroleptic-induced acute dystonia

Several antipsychotic drugs, belonging to various chemical classes, were compared for their affinity for the sigma, dopamine-D2, and muscarinic receptors. Many neuroleptic drugs were found to bind with high affinity to sigma 2 receptors, and the binding affinity was clearly different from that observed for dopamine-D2 receptors. The dopaminergic and muscarinic theories for the physiopathology of acute dystonia are not completely satisfactory. Since the sigma receptors were reported to play a role in the control of movement, the high affinity of some neuroleptics for these sites suggests their possible involvement in some side effects, such as drug-induced dystonia. There was a correlation between the clinical incidence of neuroleptic-induced acute dystonia and binding affinity of drugs for the sigma receptor, except for some drugs, with a lower incidence, displaying significant affinity for the cholinergic muscarinic receptor. Therefore, we conclude that the affinity for the sigma receptor might be involved in neuroleptic-induced acute dystonia, but this might be partially corrected by the intrinsic anticholinergic properties of the drug.

Drug-induced movement disorders

Parkinsonism, tremor, chorea-ballismus, dystonia, tardive dyskinesia, myoclonus, tics and akathisia can be induced by many drugs. The drugs that are most frequently implicated in movement disorders are antipsychotics, calcium antagonists, orthopramides and substituted benzamides (e.g. metoclopramide, sulpiride, clebopride, domperidone), CNS stimulants, antidepressants, anticonvulsants, antiparkinsonian drugs and lithium. It is possible for a single drug to induce 2 or more types of movement disorders in the same patient. Movement disorders are not always reversible after drug withdrawal.

Adverse effects of antipsychotic agents. Do newer agents offer advantages?

Although antipsychotic drugs are effective in treating the so-called positive features of schizophrenia, between one-quarter and one-third of patients respond poorly. Furthermore, the incidence of adverse effects is high, especially those reflecting disruption of extrapyramidal function, and is a major source of non-compliance. There is a clear need for new compounds that are more efficacious and/or better tolerated. Until recently, the classical dopamine hypothesis, with its emphasis on D2 blockade as the key mechanism of antipsychotic action, dominated drug development, though the emphasis is now shifting. Three 'new' antipsychotics have reached the international market in the past 5 years-the newly rehabilitated clozapine and the genuinely new remoxipride and risperidone. Claims of enhanced tolerability have been made for each of these, but as none is free from adverse effects, their place in treatment can only be meaningfully established in relation to the efficacy of each in different clinical situations. Clozapine has an extensive profile of general, nonhaematological adverse effects which is slightly different in emphasis from, but comparable in incidence to, that of chlorpromazine. There is a 0.8% risk of agranulocytosis in the first year of exposure, which can be fatal, though the boundary separating it from other (especially phenothiazine) antipsychotics in this regard is becoming increasingly blurred. It has a clearly diminished liability to cause extrapyramidal adverse effects. Its proven efficacy in operationally defined treatment-resistant schizophrenia and in patients intolerant to the extrapyramidal adverse effects of standard drugs establishes its credentials for advantage in these groups. There is on present evidence, however, only a hint of enhanced efficacy in acute schizophrenia: this requires further investigation. Open maintenance studies provide impressive data on long term outcome, especially in terms of quality-of-life parameters, but this issue requires to be addressed in blind, randomised trials. Until such additional information is forthcoming the risks and consequent costs would not justify extension of its use. The evidence to date is that reported benefits in so-called negative features probably reflect its favourable neurological profile. While the advantages of clozapine are undoubted, they remain as yet restricted to selected patient groups. Remoxipride has a good general tolerability profile, its special strength being its low sedative effect. However, its reported association with aplastic anaemia has severely restricted its use, and regular haematological monitoring is required. Although remoxipride appears to have a lower liability to produce extrapyramidal adverse effects than the high potency haloperidol, its benefits relative to other low potency compounds in this regard remain unproven. The only obvious situation in which its risks and consequent costs would be justified would seem to be patients with established compliance problems as a result of intrusive sedation with standard drugs. The position of other benzamides such as raclopride and amisulpride remains to be established. Risperidone, perhaps from its antiadrenergic actions, has more in the way of cardiovascular adverse effects than haloperidol, though these can be obviated by graded early exposure. It may also be associated with greater weight gain. Otherwise it appears to be well tolerated. In comparison with haloperidol, it appears to be associated with a lower prevalence of acute extrapyramidal adverse effects in dosages < or = 10 mg/day, the most potentially important component of which is its reportedly insignificant likelihood of promoting akathisia. These conclusions emerge from comparisons with haloperidol in doses many might consider somewhat high. The question of the advantage of risperidone over low or milligram-equivalent haloperidol regimens remains open.(ABSTRACT TRUNCATED)