clozapine and Xerostomia

Clozapine, an atypical antipsychotic used to treat people with schizophrenia, has been proposed as a possible treatment for salivary gland hypofunction. This scoping review investigated the available literature on clozapine's impact on salivary flow, in order to determine whether it could be used by dental practitioners in low doses as a treatment for dry mouth.. An electronic search was completed using Ovid MEDLINE (1996 to Nov 2021). Key MeSH search terms included "clozapine," "Clozaril," "salivation," "salivary flow rate," "sialorrhea," "hypersalivation," and "drooling." Two reviewers independently reviewed eligible articles and extracted the data based on the inclusion and exclusion criteria.. The initial search identified 129 studies, six of which were included in this review. Four of them (one cross-sectional and three interventional) described salivary flow rates in schizophrenic patients taking clozapine, while one of those and two others focused on the mechanism of clozapine-induced sialorrhea, with one study covering both. There were mixed findings, with one study observing a moderate association between clozapine dose and salivary flow, and the others reporting no differences. Findings on the putative mechanisms for clozapine-induced sialorrhea (CIS) were inconclusive.. There is insufficient high-quality information to justify using low-dose clozapine to increase salivary flow in dental patients with salivary gland hypofunction. Well-designed interventional studies and randomized control trials are required.

Topics: Antipsychotic Agents; Clozapine; Cross-Sectional Studies; Dentists; Humans; Professional Role; Sialorrhea; Xerostomia

Olanzapine is structurally similar to clozapine but has not been shown at routine doses to share the superiority of clozapine to traditional antipsychotics in treatment-resistant patients. Olanzapine, however, has been increasingly used in higher doses as clinicians attempt to find a more tolerable therapy for those refractory to conventional agents. This study examined the relationship of high-dose olanzapine plasma concentrations to symptoms, adverse effects, smoking, and gender. Thirteen patients participated in a double blind 16-week crossover study (8 weeks each arm) of olanzapine (50 mg/day) compared to clozapine (450 mg/day). Women had significantly higher plasma olanzapine levels than men at each time point in each arm (weeks 4, 6, and 8). At 8 weeks women had a steady-state olanzapine level of 278 +/- 62 ng/ml while men had a steady-state level of 127 +/- 47 ng/ml (p = 0.005). At week 4, olanzapine levels tended to be higher in those who had been on clozapine previously (205 ng/ml) compared to those who received olanzapine in the first arm (105 ng/ml). Cigarette intake was negatively correlated to olanzapine plasma concentrations (week 8: r = -0.86, p < 0.05). Plasma levels were significantly higher in those experiencing constipation (176 vs. 82 ng/ml; p = 0.022). Plasma levels of olanzapine were not associated with symptom response and anticholinergic effects were seen at greater frequency with higher olanzapine concentrations. In conclusion, this study reports plasma olanzapine levels at high fixed doses of olanzapine (50 mg/day) in relation to side effects, symptoms, smoking, and gender.

Topics: Adult; Antipsychotic Agents; Benzodiazepines; Clozapine; Constipation; Cross-Over Studies; Double-Blind Method; Drug Monitoring; Female; Humans; Male; Olanzapine; Risk Factors; Schizophrenia; Severity of Illness Index; Sex Characteristics; Sex Factors; Smoking; Time Factors; Treatment Outcome; Vision Disorders; Xerostomia

Despite the demonstrated efficacy of clozapine in severely refractory schizophrenia, questions remain regarding its efficacy for primary negative symptoms, comparison with a moderate dose of a first-generation antipsychotic, and adverse effects during a longer-term trial. This study examined its efficacy in partially responsive, community-based patients, compared clozapine with moderate-dose haloperidol, and extended treatment to 6 months.. Randomized, double-blind, 29-week trial comparing clozapine (n = 37) with haloperidol (n = 34). Subjects with schizophrenia who were being treated in community settings at 3 collaborating clinical facilities were enrolled.. Subjects treated with haloperidol were significantly more likely to discontinue treatment for lack of efficacy (51%) than were those treated with clozapine (12%). A higher proportion of clozapine-treated subjects met an a priori criterion of improvement (57%) compared with haloperidol-treated subjects (25%). Significantly greater improvement was seen in symptoms of psychosis, hostile-suspiciousness, anxiety-depression, thought disturbance, and total score measured on the Brief Psychiatric Rating Scale. No differences were detected in negative symptoms using the Brief Psychiatric Rating Scale or the Schedule for Assessment of Negative Symptoms. Subjects treated with clozapine experienced more excess salivation, dizziness, and sweating and less dry mouth and decreased appetite than those treated with haloperidol.. Compared with a first-generation antipsychotic given in a moderate dose, clozapine offers substantial clinical benefits to treatment-refractory subjects who can be treated in the community. Advantages are seen in a broad range of symptoms but do not extend to negative symptoms.

Topics: Adult; Anorexia; Antipsychotic Agents; Brief Psychiatric Rating Scale; Clozapine; Dizziness; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Haloperidol; Humans; Male; Psychiatric Status Rating Scales; Psychotic Disorders; Schizophrenia; Schizophrenic Psychology; Treatment Outcome; Xerostomia