Extrapyramidal side effects risperidone

Risperidone (Risperdal). Risperidone is also approved by the FDA for the treatment of acute mania. It acts as an atypical antipsychotic at doses up to 4-6mg/day. Over this dose, and at lower doses in children and the elderly, risperidone acts more like a typical antipsychotic in that extrapyramidal side effects are common. 

We prefer low doses of atypical antipsychotics as a first-line treatment. In this way, the threat of extrapyramidal symptoms is largely avoided without having to use a second anticholinergic medication to offset antipsychotic side effects. Risperidone 0.25-0.5mg/day, olanzapine 2.5mg/day, quetiapine 25mg/day, ziprasidone 20mg/day, or aripiprazole 2.5-5mg/day are reasonable starting doses. The typically higher doses used to treat schizophrenia are usually not necessary. 

The conventional antipsychotics have little effect on the negative psychotic symptoms such as autism, stupor and emotional withdrawal. The so-called atypical antipsychotics, or second-generation antipsychotics, like the heterocyclic compound risperidone, the benzamide sulpiride and several diben-zepines of which clozapine is the best known, have a broader spectrum which means that they also have an effect on the negative psychotic symptoms. Most share a common attribute of working on serotonin receptors as well as dopamine receptors. They have a low risk of extrapyramidal side effects. 

EPS, extrapyramidal side effects HPD, haloperidol MLD, molindone N, total number of subjects in study , number of preschool-age children in study RCT, randomized, double-blind, controlled trial RISP, risperidone SE, side effect TFP, trifluperidol THX, thiothixene. 

Atypical neuroleptics. Because of the limited effectiveness and safety of conventional neuroleptics in TS, clinicians have turned to a new generation of neuroleptics that have been introduced for the treatment of schizophrenia. Risperidone, a member of a class of antipsychotics that blocks both DA and serotonin receptors, has been established as superior to placebo and equal, or superior, to haloperidol in the treatment of schizophrenia (Chouinard et al. 1993 Marder and Meibach 1994]. Risperidone has a more favorable side-effect profile than that of conventional neuroleptics and may have less potential for producing tardive dyskinesia. Compared with haloperidol, fewer extrapyramidal side effects are observed with risperidone in doses of 6 mg/ day or less. As encouraging reports appear in the literature (Lombroso et al. 1995 Stamenkovic et al. 1994 van der Linden et al. 1994], risperidone is currently being widely used by clinicians to treat tic disorders. 

Quetiapine also has a chemical structure related to that of clozapine (Fig. 11—36), but it has several differentiating pharmacologic (Fig. 11—41) and clinical features, not only as compared with clozapine (Fig. 11—37) but also as compared with risperidone (Fig. 11-39) and olanzapine (Fig. 11-40). Quetiapine is very atypical in that it causes virtually no EPS at any dose and no prolactin elevations. Thus, quetiapine tends to be the preferred atypical antipsychotic for patients with Parkinson s disease and psychosis. It is also useful in schizophrenia, bipolar disorder, and other types of psychosis, in which it has few extrapyramidal side effects. 

Owens DG. Extrapyramidal side effects and tolerability of risperidone a review. J Clin Psychiatry 1994 55(Suppl 5) 29-35. 

Risperidone has been developed as a combined D2/5-HT2A receptor antagonist. In addition, it has a high affinity for 5-HT1A and 5-HT7 receptors. Whether such an effect has any relevance to its beneficial effects on the negative symptoms of schizophrenia, and lack of extrapyramidal side effects at moderate therapeutic doses, is unknown. An important advantage of risperidone over clozapine lies in its lack of antagonism of muscarinic receptors. 

Leucht S, Pitschel-Walz G, Abraham D, Kissling W. Efficacy and extrapyramidal side-effects of the new anti-psychotics olanzapine, quetiapine, risperidone, and sertin-dole compared to conventional antipsychotics and placebo. A meta-analysis of randomized controlled trials. Schizophr Res 1999 35(1) 51—68. 

Magnuson TM, Keller BK, Burke WJ. Extrapyramidal side effects in a patient treated with risperidone plus donepezil. Am J Psychiatry 1998 155(10) 1458-9. 

ARIPIPRAZOLE, HALOPERIDOL, CLOZAPINE, PIMOZIDE, RISPERIDONE, SERTINDOLE PROTEASE INHIBITORS Possibly T levels of antipsychotic Inhibition of CYP3A4- and/or CYP2D6-mediated metabolism Avoid co-administration of clozapine with ritonavir, and pimozide or sertindole with protease inhibitors. Use other antipsychotics with caution as 1 dose may be required with risperidone, watch closely for extrapyramidal side-effects and neuroepileptic malignant syndrome... 

Conventional antipsychotics improve symptoms of hyperactivity and impulsivity, but may have negative effects on learning and cognitive functioning as well as extrapyramidal side effects (e.g., dystonia and tardive dyskinesia) that limit their usefulness. The atypical antipsychotics risperidone, olanzapine, quetiapine, and ziprasidone have been used to control severe aggression in refractory cases of ADHD, particularly if conduct disorder or bipolar disorder coexists. More studies are needed to clarify their place in therapy. ... 

Attenuation of brain dopamine (DA) neurotransmission has been widely recognized as a useful mechanism for the treatment of the psychotic symptoms of schizophrenia.1-3 Antagonism of DA receptors is a major component of the mechanism of action of classical antipsychotic agents such as haloperidol and chlorpromazine as well as the newer atypical agents such as clozapine,4,5 risperidone,6 sertindole,7 and olanzapine.8 9 However a significant portion of schizophrenic patients do not respond to DA antagonist therapy and their use is often limited by a variety of severe side effects including extrapyramidal side effects (EPS) and tardive dyskinesia (TD).10-12 While atypical antipsy-... 

At present there are several medications that have been approved that involve the neurochemical serotonin. The first two medications are clozapine and risperidone and the two newer medications are Seroquel and Zyprexa. To date, these medications have been termed the atypical antipsychotic medications, because they are effective in reducing symptoms of schizophrenia and are less likely to cause extrapyramidal side effects than the other antipsychotic medications (Karper Krystal, 1996). 

RISPERDAL), for example, is a potent S-HT and receptor antagonist. Low doses of risperidone have been reported to attenuate negative symptoms of schizophrenia with a low incidence of extrapyramidal side effects. Extrapyramidal effects are commonly seen, however, with doses of risperidone in excess of 6 mg/day. Other atypical antipsychotic agents—quetiapine (seroquel) and olanzapine (zyprexa)—act on multiple receptors, but their antipsychotic properties are thought to be due to antagonism of DA and 5-HT. 

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