Risperidone clozapine

Like clozapine, risperidone has been subjected to all levels of pharmacoeconomic evaluation. For example, two health-care models have predicted substantial savings resulting from the use of risperidone (Keks, 1997 Davies et al, 1998). 

Side Effect Clozapine Risperidone Olanzapine Quetiapine Ziprasidone Aripiprazole Haloperidol... 

The vast majority of children with enuresis have normal uro-dynamics, including nocturnal bladder capacity. Functional bladder capacity can be estimated using this formula age in years + 2 = ounces of capacity. In some children, there appears to be a relationship between developmental immaturity (motor and language milestones) and enuresis, but the mechanism is unknown. Drugs like lithium, clozapine, risperidone,... 

Psychopharmaco-epidemiology investigation in China in 2002 showed that the first six antipsychotic drugs used for schizophrenia were clozapine, risperidone,... 

Considerable interest has been generated with the development of the atypical antipsychotics (Potenza and McDougle, 1998). Reports have now appeared in which clozapine, risperidone, olanzapine, or quetiapine were used in the treatment of autistic disorder and other PDDs. The reader is referred to other recent publications that provide a more comprehensive review of atypical antipsychotics in autistic disorder and other PDDs (McDougle et ah, 2000b Posey and McDougle, in press). 

In most cases, SSRIs are the first choice for drugs to combat OCD. Clomipramine, fluvoxamine, fluoxetine, paroxetine, sertraline, and citalopram are all SSRIs that have been proven effective in reducing OCD symptoms. However, in about 40 to 60% of patients, these drugs do not completely alleviate all the symptoms. When this is the case, a second type of drug called a neuroleptic is often added. Neuroleptic drugs, such as haloperidol, clozapine, risperidone, and chlorpromazine... 

P450 IID6 -fin women Inhibited by OCs Hydroxylation of nortriptyline and desipramine, haloperidol, clozapine, risperidone, venlafaxine Fluoxetine, fluvoxamine, paroxetine, sertraline... 

Risperidone, a novel benzisoxazole derivative, is an atypical antipsychotic medication that combines dopamine D2 receptor antagonism with potent 5-HT2 receptor antagonism. Risperidone has a higher affinity for dopamine D2 receptors than does clozapine. Risperidone also antagonizes dopamine Dj and D4 receptors, aj- and a2-adrenergic receptors, and histamine Hj receptors. Although the optimal dose of risperidone in North American trials was 6 mg/day, subsequent clinical experience has indicated that most patients do well at lower doses of 3-6 mg/day, and elderly patients may require doses as low as 0.5 mg/day. Unlike other atypical antipsychotics. 

Although positive symptoms are usually the focus of acute intervention and are at least partially responsive to neuroleptics, cognitive, mood, and negative symptoms are generally more debilitating, are less responsive to conventional agents, and may be more responsive to novel antipsychotics (e.g., clozapine, risperidone, olanzapine, quetiapine, ziprasidone). 

A wide range of disorders can benefit from antipsychotic therapy. For example, since the introduction of antipsychotics, 25% fewer hospital beds are occupied by patients with schizophrenia. In particular, the newer antipsychotics hold the promise of benefitting patients once refractory to conventional treatment. Thus, negative, cognitive, and mood symptoms may improve with use of newer agents such as clozapine, risperidone, olanzapine, quetiapine, and ziprasidone. 

The introduction of clozapine, risperidone, quetiapine, and ziprazidone has had a dramatic impact on the decision-making process in choosing an antipsychotic. Thus, these agents both minimize neurological adverse effects and may qualitatively improve some psychotic symptoms to a greater degree than neuroleptics. 

Clozapine, risperidone, olanzapine, quetiapine, and ziprasidone have all been approved for the treatment of schizophrenia. Data from long-term open evaluations of clozapine demonstrate that improvement is maintained over time, even when the dose is reduced. Further, patients did not develop tolerance to its antipsychotic effect. Naturalistic reports indicate that an adequate trial for acute response in some patients may be at least 6 months. Further, a small number (8 of 14) of previously refractory patients were successfully maintained on clozapine for up to 2 years ( 215). 

As noted earlier, evidence indicates that atypical antipsychotics may also produce NMS ( 488). Several patients have developed NMS after treatment with clozapine, risperidone, or olanzapine. A few of these cases are classic NMS, with symptoms such as markedly elevated temperature and CPK levels. For each drug, approximately a dozen reported cases fulfill a reasonably stringent criteria for NMS, whereas the rest can be considered borderline. The number of NMS cases, however, appears low relative to use. In addition, some of the patients on clozapine who developed NMS were also receiving neuroleptics. There are cases of patients who had NMS on clozapine alone, however, and when rechallenged with clozapine experienced another NMS episode. Similarly, rechallenge with olanzapine- or risperidone-induced NMS has resulted in either questionable or definite reemergence of NMS. 

Kapur S, Zipursky RB, Remington G. Clinical and theoretical implications of 5-HT 2 and D2 receptor occupancy of clozapine, risperidone, and olanzapine in schizophrenia. Am J Psychiatry 1999 156 286-293. 

Aripiprazole Blockade of 5HT2A receptors > blockade of D2 receptors Some a blockade (clozapine, risperidone, ziprasidone) and M-receptor blockade (clozapine, olanzapine) variable receptor blockade (all) Schizophrenia—improve both positive and negative symptoms bipolar disorder (olanzapine or risperidone adjunctive with lithium) agitation in Alzheimer s and Parkinson s (low doses) major depression (aripiprazole) Toxicity Agranulocytosis (clozapine), diabetes (clozapine, olanzapine), hypercholesterolemia (clozapine, olanzapine), hyperprolactinemia (risperidone), QT prolongation (ziprasidone), weight gain (clozapine, olanzapine)... 

In 2007 Zarrouf and Bhanot published the most extensive recent review and identified 88 reports of NMS associated with six atypical neuroleptics olanzapine, clozapine, risperidone, ziprasidone, quetiapine, and aripiprazole. As a warning to those doctors who cavalierly resume neuroleptics once the NMS has gone into remission, 20 cases showed a clear history of prior NMS, indicating that a patient s first case of NMS predisposes toward another when reexposed to neuroleptics. Olanzapine (Zyprexa) has been touted as being relatively free of the risk of NMS, but the authors located 36 cases. 

Avenoso A, Facciola G, Scordo MG, Gitto C, Ferrante GD. No effect of citalopram on plasma levels of clozapine, risperidone and their active metabolites in patients with chronic schizophrenia. Clin Drug Invest 1998 16 393-8. 

Breier AF, Malhotra AK, Su TP, Pinals DA, Elman I, Adler CM, Lafargue RT, Clifton A, Pickar D. Clozapine risperidone in chronic schizophrenia effects on symptoms,... 

Miller CH, Mohr F, Umbricht D, Woerner M, Fleischhacker WW, Lieberman JA. The prevalence of acute extrapyramidal signs and symptoms in patients treated with clozapine, risperidone, and conventional antipsychotics. J Clin Psychiatry 1998 59(2) 69-75. 

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