Clozapine: the correlation between clinical improvement and laboratory parameters

[摘要] English: In this study, fifteen Black patients suffering fromacute schizophrenia were treated with clozapine fora period of 40 days in order to ascertain whethercertain laboratory parameters could be utilized togive an indication of the clinical efficacy of clozapinetreatment in these patients.S.l.l Therapeutic efficacyUtilizing the B.P.R.S. and F.C. rating scale asindication of the clinical improvement of thepatients, it was found that significant clinicalimprovement occurred upto day 30 whereafter clinicalimprovement was only slight. Clozapinewas well tolerated by all the patients while morethan half the patients (53,3%) were fit for unmndhionaldischarge on completion .of the study.On completion of the study the working capacityof the majority (80%) was satisfactory.5.1.2 Side effectsThe most common side effects encountered were daytimesedation which was especially prominent duringthe early stages of the study and hypersalivation which occurred with equal frequency throughout thestudy period. Other side effects encountered indescending order of frequency were nausea andvomiting, dizziness, headache, disturbance of visual accomodation, constipation and diarrhoea, disturbedsleep, sweating, inhibition of micturition, andcollapse.5.1.3 Blood pressure and pulse rateClozapine had no significant' prolongated effecton blood pressure while a significant and sustainedrise in pulse rate during the treatment period wasnoted. It is suggested that this rise in pulserate could be utilized as a convenient clinical aidin checking patient compliance in patients beingtreated with clozapine.5.1.4 Serum concentration of clozapine, clozapine plusmetabolites, and metabolites only.5.1.4.1 No correlation was found between serumlevels of clozapine, clozapine plus itsmetabolites, or its metabolites only andclinical improvement.5.1.4.2 It was found that on treatment day 5 steadystate serum levels of clozapine and ofclozapine plus it metabolites had beenreached.5.1.4.3 No auto-induction of the metabolism ofclozapine appeared to occur during thetreatment period.5.1.4.4 No accumulation of clozapine or its metabolitesappeared to occur during the treatmentperiod.5.1.4.5 It can be concluded that a certain periodof exposure to a more or less constantserum level of clozapine and/or its metabolitesis necessary to effect clinicalimprovement.5.1.4.6 A significant correlation was found betweenthe lying pulse rate and serum levels ofclozapine plus its metabolites. The lyingpulse rate can thus offer a reasonable indicationof the expected serum levels ofclozapine plus its metabolites.5.1.5 Prolactin serum levelsNo rise in serum prolactin levels occurred in thesepatients after institution of treatment with clozapine.Therefore no correlation between clinicalimprovement and prolactin serum levels could beascertained.5.1.6 5-hydroxytryptamine-induced platelet aggregationNo enhancement of 5-HT-induced platelet aggregationcould be determined in these patients undergoingtreatment with clozapine. Therefore no correlationcould be established between clinical improvementand enhancement of 5-HT-induced platelet aggregation.5.1.7 Plasma cholinesterase and red blood cell ace~-cholinesterase activitX'Both the plasma cholinesterase and red blood cell acetylcholinesterase activity fell within thenormal range prior to the institution of treatmentwith clozapine. These parameters cantherefore not be used as diagnostic aids in thediagnosis of schizophrenia. The activity ofboth parameters also fell within the normal rangeon conclusion of the study. It would thusappear that treatment with clozapine did notsignificantly affect these·.parameters.

[发布机构] University of the Free State