Risperidone Haloperidol

Recently, three papers have reported the determination of risperidone and its active metabolite 9-hydroxyrisperidone using LLE and SPE technologies. The analytical columns used to separate these compounds were C4 or C18 bonded phases of 3 pm or 5 pm particle sizes with UV/VIS detection. Mobile phases consisted of phosphate bufiers (pH 3-4) in acetonitrile. The sample volumes used ranged from 200 pi to 1 ml, with extraction recoveries averaging 90%. The limits of quantitation ranged from 0.5 to 10 ng/ml in human plasma (Nagasaki et al., 1999 Avenso et al., 2000 Titier et al., 2002). A study by Titier showed the simultaneous determination of clozapine, olanzapine, haloperidol, risperidone, and its active metabolites by RP-HPLC in human plasma. The assay involved LLE with a hexane/isoamyl alcohol mixture... 

Chlorpromazine, thioridazine, perphenazine, haloperidol, reduced haloperidol, risperidone, clozapine, sertindole Others... 

Psychosis Intravenous haloperidol Risperidone/atypicals Low potency neuroleptics... 

Janicak et al. (113, 283) recently reported the results of a double-blind, randomized trial of risperidone monotherapy versus haloperidol monotherapy for controlling both psychotic and mood symptoms in 62 patients with schizoaffective disorder (bipolar or depressed subtype). These authors observed that, in comparison with haloperidol, risperidone was as follows ... 

Cyt 2D6 metabolizes haloperidol, risperidone, thioridazine, sertindole, olanzapine and clozapine common substrates - fluoxetine, paroxetine, sertraline, venlafaxine, amitriptyline, clomipramine, desipramine, imipramine, nortriptyline, propranolol, metoprolol, timolol, codeine, encainide, flecanide. Common inhibitors - paroxetine, sertraline, fluoxetine. 

Rosengarten, H. Quartermain, D. 2002, Effect of prenatal administration of haloperidol, risperidone, quetiapine and olanzapine on spatial learning and retention in adult rats, Pharmacol.Biochem.Behav., vol. 72, no. 3, pp. 575-579. 

Peuskens J. Risperidone in the treatment of patients with chronic schizophrenia a multi-national, multi-centre, doubleblind, parallel-group study versus haloperidol. Risperidone Study Group. Br J Psychiatry 1995 166(6) 712-26. 

Liquid concentrate Haloperidol, risperidone Same as above... 

Depot oil suspension Fluphenazine, haloperidol, risperidone Slow release allows for dosing every 2-4 weeks... 

ANTIPSYCHOTICS-CHLORPROMAZINE, CLOZAPINE, HALOPERI-DOL, OLANZAPINE, PERPHENAZINE, RISPERIDONE, SERTINDOLE, THIORIDAZINE, ZUCLOPENTHIXOL H2 RECEPTOR BLOCKERS -CIMETIDINE t plasma concentrations of these antipsychotics, with risk of associated adverse effects Cimetidine is an inhibitor of CYP3A4 (sertindole, haloperidol, risperidone), CYP2D6 (chlorpromazine, risperidone, zudopenthixol, thioridazine, perphenazine) and CYP1A2 (clozapine, olanzapine, sertindole, haloperidol) Avoid concomitant use. Choose an alternative acid suppression, e.g. H2 antagonist... 

CYP2D6 Antidepressants amitriptyline, clomipramine, imipramine, desipramine, nortriptyline, trimipramine, N-desmethyl-clomipramine, fluoxetine, norfluoxetine, paroxetine, venlafaxine, sertraline Neuroleptics chlorpromazine, thioridazine, perphenazine, haloperidol, reduced haloperidol, risperidone, clozapine, sertindole Others codeine, opiate, propranolol, dextromethorphan 4 no activity 25% in Caucasians 0%-10% in others 5 no activity 2%-10% in all groups 10 reduced activity 47%-70% in Asians <5% in others 17 reduced activity 25%-40% in blacks 0% in others 2XN increased activity 19%-29% in Arabs and Ethiopians <5% in others... 

A number of unapproved uses of antipsy- chotic drugs also exist. CPZ and haloperidol were used early on to treat phencyclidine (PCP)-induced psychosis. Psychoses associ- ated with depression, bipolar disorder, and Alzheimer s disease are commonly treated with haloperidol, risperidone, or olanzapine. Psychotic symptoms in Parkinson s disease patients caused by levodopa and/or dopaminergic agonists have been alleviated with quetiapine, because EPS-prone typical neuroleptics contraindicated in Parkinson s disease. 

Rats reared in isolation after weaning also experience deficits in PPI (159) and decreased social interaction. This effect has been attributed to enhanced dopaminergic activity (160). Isolation rearing deficits are maximal at puberty (161,162) and thus parallel the ontog-eny of schizophrenia in humans. The disruption of PPI in young rats reared in isolation is reversed by a broad spectrum of antipsychotic drugs including haloperidol, risperidone, clozapine, olanzapine, and quetiapine (153,163). 

Amitriptyline -Clomipramine Desipramine Imipramine Paroxetine Antipsychotics Haloperidol Risperidone Thioridazine Codeine... 

Simultaneous alprazolam, chlorpromazine, diazepam, levomepromazine, nitrazepam Noninterfering haloperidol, risperidone... 

---