Use of Quetiapine to Manage Patients Who Experienced Adverse Effects with Clozapine

Aripiprazole as an Adjunct to Clozapine Therapy in Adolescents with Early-onset Schizophrenia: A Retrospective Chart Review

“…Apart from the study of Chang et al, there are presently three prospective studies listed under www.clinicaltrials.gov (accessed 15 December 2008), which aim to assess clozapine / aripiprazole combination treatment in patients with schizophrenia (NCT00395915: Head-to-head comparison vs. clozapine / haloperidol, NCT00345033: eff ect on side eff ects, NCT00300846: eff ect on weight). For quetiapine augmentation, there is data accessible from a retrospective study, suggesting a dose-dependency of clozapine-side eff ects [19] and from a single-blind, randomized head-to-head trial with amisulpride, showing slight symptom improvement [8] . Additionally, data from case reports, case series or retrospective studies on clozapine augmentation with pimozide, olanzapine, loxapine, haloperidol and chlorpromazine is available (overview: Mouff ak et al [17] ).…”

Augmentation of Clozapine with Atypical Antipsychotic Substances

“…Some studies aimed to tackle incompletely remitted positive and/or negative schizophrenic symptoms, while some also or primarily focused on the reduction of clozapine-induced side effects. Sample sizes differed massively, ranging from single case reports to large groups of up to 1000 patients in the evaluation of quetiapineaugmentation [39]. Fourteen publications deal with the combination of clozapine and risperidone in 53 patients.…”

“…Under these conditions, we do not see any evidence for switching attempts, preferring a combined regimen. Specific unfavorable side effects of clozapine such as sedation, increased body weight and liability to epileptic seizures are dose dependent [39]. They constrain the patient's compliance and may be ameliorated with dose reduction after addition of a second antipsychotic substance with a different spectrum of side effects.…”

“…Two studies reporting on an at least partially overlapping study sample [39,61] deal with quetiapine as an add-on and impress on account of their large sample size (1000 patients) as compared to other publications. The authors mainly focused on reducing unfavorable side effects of clozapine including body weight gain, constipation, hypersalivation and diabetes mellitus.…”

“…In contrast, amisulpride in combination with clozapine resulted in higher dose-corrected plasma levels as compared to an amisulpride monotherapy [37]. As well, several publications report about substantial clozapine dose reductions and relief of clozapine side effects [25,39,44].…”