fluvoxamine and Hyperlipidemias

Adjunctive fluvoxamine inhibits clozapine metabolism and decreases plasma norclozapine (a toxic metabolite of clozapine) to clozapine ratios. This study aimed to demonstrate the effects of fluvoxamine on clozapine-related weight gain, hyperglycemia, and lipid abnormalities.. Sixty-eight treatment-resistant inpatients with a DSM-IV diagnosis of schizophrenia were randomly assigned to 2 treatment groups for 12 weeks. The monotherapy group (N = 34) received clozapine (< or = 600 mg/day). The coadministration group (N = 34) received fluvoxamine (50 mg/day) plus low-dose clozapine (< or = 250 mg/day). The study was conducted from August 1999 to October 2002.. The 2 groups were similar in demographic data; baseline body weight and body mass index (BMI); baseline serum glucose, triglyceride, and cholesterol levels; and steady-state plasma clozapine concentration. The monotherapy patients (but not the coadministration patients) had significantly higher (p < .05) body weight, BMI, and serum glucose and triglyceride levels after treatment than at baseline. At week 12, the monotherapy patients also had significantly higher glucose (p = .035), triglyceride (p = .041), and norclozapine (p = .009) (and numerically higher cholesterol) levels than the cotreatment patients. The changes in weight and serum glucose and triglyceride levels were significantly correlated (p = .026, p = .005, and p = .028, respectively) with the plasma concentration of norclozapine but not with plasma levels of clozapine.. These results suggest that fluvoxamine cotreatment can attenuate weight gain and metabolic disturbances in clozapine-treated patients. Plasma levels of norclozapine, but not clozapine, are associated with increases in weight and serum glucose and triglyceride levels. Of note, coadministration of fluvoxamine could increase plasma clozapine levels markedly and carry the risk of adverse events. If this combined treatment is applied, conservative introduction with reduced clozapine dosage and careful therapeutic drug monitoring of clozapine concentration is recommended.

Topics: Adolescent; Adult; Antipsychotic Agents; Blood Glucose; Cholesterol; Clozapine; Drug Interactions; Drug Monitoring; Drug Therapy, Combination; Female; Fluvoxamine; Humans; Hyperglycemia; Hyperlipidemias; Male; Middle Aged; Selective Serotonin Reuptake Inhibitors; Triglycerides; Weight Gain

Many clinical reports and trials have suggested that fluvoxamine (FLV) reduces plasma lipoprotein levels. However, few studies have reported the effect of plasma lipoproteins on FLV pharmacokinetics. The aim of the present study was to investigate the affinities of FLV to plasma lipoproteins and the effect of plasma lipoproteins on the biodistribution of FLV using an experimental hyperlipidemic (HL) rat model.. HL rats were prepared by intraperitoneal administration of Poloxamer-407 solution (1.0 g/kg). In vitro protein binding and distribution of FLV in plasma lipoproteins were determined in control and HL rats. In vivo pharmacokinetic study (intravenous administration of FLV, 5.0 mg/kg) and biodistribution analysis for brain and liver at a steady state (infusion, 1.5 mg/kg/hr, 6 hrs) were also performed.. The plasma protein binding of FLV was around 83% and 95% in control and HL rats, respectively, whereas the FLV recoveries in triglyceride-rich lipoprotein fractions were increased in HL. Therefore, the elevation of lipoproteins was likely responsible for the increase in protein binding in HL. After intravenous administration, the area under the plasma concentration vs. time curve (AUC) in HL was 3.9-fold greater than that in control rats, whereas the distribution ratio of FLV plasma concentration to the brain at a steady state was decreased to approximately 20% of that of the control.. FLV has an affinity to plasma lipoproteins, and their elevation might decrease the FLV biodistribution to brain; the plasma lipoprotein levels could not be found to correlate positively with the FLV pharmacokinetic effect in brain, but rather may attenuate it.

Topics: Animals; Area Under Curve; Biological Availability; Brain; Disease Models, Animal; Fluvoxamine; Hyperlipidemias; Injections, Intravenous; Linear Models; Lipoproteins; Liver; Male; Models, Biological; Poloxamer; Protein Binding; Rats; Rats, Wistar; Selective Serotonin Reuptake Inhibitors; Tissue Distribution; Triglycerides