Risperidone typical antipsychotics

Lee, C. et al. (2006). Treatment with olanzapine, risperidone or typical antipsychotic drugs in Asian patients with schizophrenia. Aust. N. Z. J. Psychiatry, 40, 437-45. 

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. 

When an antipsychotic is needed, we prefer using one of the newer atypical agents olanzapine, ziprasidone, risperidone, quetiapine, or aripiprazole. Each of these medications reliably reduces agitation and is well tolerated. In particular, they decrease the potential for acute dystonic reactions and tardive dyskinesia caused by the typical antipsychotics. Both ziprasidone and olanzapine are now available in an injectable form that is very rapidly acting and effective in this setting. 

In contrast to the typical antipsychotics, early evidence suggests that the newer atypical antipsychotics might be helpful for the core symptoms of PTSD. Although there have been some negative studies, several small controlled studies of olanzapine (5-20mg/day), quetiapine (25-300 mg/day), and risperidone (0.5-3 mg/day) have demonstrated improvement in PTSD reexperiencing symptoms. 

Antipsychotics in a few small studies have been shown to be helpful. To date this research is limited to typical antipsychotics. Nevertheless, the excellent track record of atypical antipsychotics in treating schizophrenia and the lower burden of side effects lead us to recommend atypical antipsychotics as a first-line treatment for STPD as well. Low doses of risperidone, olanzapine, quetiapine, ziprasidone, or aripiprazole are all reasonable options. If no therapeutic effect is observed, doses should be increased. 

Given that limitation, the only ways to counteract elevated prolactin are to lower the dose of the antipsychotic or to switch to another antipsychotic that does not elevate prolactin. We prefer switching (especially if the problem has been encountered with an older style typical antipsychotic) to an atypical antipsychotic if side effects of elevated prolactin become problematic. Most atypical antipsychotics, with the exception of risperidone when used in high doses, do not elevate prolactin. There are few compelling reasons to use a typical antipsychotic compared to the newer atypical agents. 

Hunter RH, Joy CB, Kennedy E, Gilbody SM, Song F. Risperidone versus typical antipsychotic medication for schizophrenia. Cochrane Database Syst Rev 2003. Issue 2. 

Thus, most of the atypical and some typical antipsychotic agents are at least as potent in inhibiting 5-HT2 receptors as they are in inhibiting D2 receptors. The newest, aripiprazole, appears to be a partial agonist of D2 receptors. Varying degrees of antagonism of 0-2 adrenoceptors are also seen with risperidone, clozapine, olanzapine, quetiapine, and aripiprazole. The clinical relevance of these actions remains to be ascertained. 

Older typical antipsychotic drugs, as well as risperidone and paliperidone, produce adverse effects marked by elevations of prolactin, see Adverse... 

Stanilla et al. (1997) described three cases of delirium with psychotic symptoms due to clozapine withdrawal (see also Adams et al., 1991, for an early report of clozapine withdrawal psychosis). They believed that clozapine produces more severe withdrawal symptoms than typical antipsychotic agents. In a 3-year open label study of quetiapine, Margolese et al. (2004) switched 23 male patients from classical antipsychotics and risperidone to quetiapine Six of the seven patients who relapsed after being stabilized on quetiapine for at least three months met the criteria for supersensitivity psychosis. This is a very high rate, again raising questions about whether atypicals may be more prone to cause tardive psychosis. 

Honey GD, Bullmore ET, Soni W, Varatheesan M, Williams SC, et al. 1999. Differences in frontal cortical activation by a working memory task after substitution of risperidone for typical antipsychotic drugs in patients with schizophrenia. Proc Natl Acad Sci USA 96 13432-13437. 

Akathisia has been reported in 16% of patients taking olanzapine (SEDA-21, 56). Three patients developed severe akathisia during treatment with olanzapine (20-25 mg/day) (87). In two, the akathisia resolved after withdrawal of olanzapine and in one of those olanzapine was well tolerated when reintroduced in combination with lorazepam. In the third patient, the akathisia was controlled by dosage reduction. A 33-year-old man with AIDS and a prior history of extrapyramidal symptoms with both typical antipsychotic drugs and risperidone developed dose-dependent akathisia with olanzapine 15-19 mg/day the akathisia responded to dosage reduction and beta-blockade (88). 

Other new atypical antipsychotics are not associated with an increased risk of agranulocytosis (unlike typical antipsychotics), are less likely to cause acute EPS, and probably are associated with a lesser risk of TD. Risperidone, another atypical agent, is not associated with an excessive risk of agranulocytosis but is highly... 

---