Pharmacokinetics of Aripiprazole and Concomitant Lithium and Valproate

The objective of this study was to assess the pharmacokinetics of the antipsychotic aripiprazole when coadministered with lithium or valproate. Two open-label, sequential treatment design studies were conducted in chronically institutionalized patients with schizophrenia or schizoaffective disorder requiring treatment with lithium (n = 12) or valproate (divalproex sodium) (n = 10). Patients received aripiprazole 30 mg/day on days 1 to 14 and aripiprazole with concomitant therapy on days 15 to 36. Lithium was titrated from 900 mg until serum concentrations reached 1.0 to 1.4 mEq/L for at least 5 days. Valproate was titrated to 50 to 125 mg/L. Coadministration with lithium increased mean Cmax and AUC values of aripiprazole by about 19% and 15%, respectively, whereas the apparent oral clearance decreased by 15%. There was no effect on the steady-state pharmacokinetics of the active metabolite of aripiprazole. Coadministration with valproate decreased the AUC and Cmax of aripiprazole by 24% and 26%, respectively, with minimal effects on the active metabolite. Therapeutic doses of lithium and divalproex had no clinically significant effects on the pharmacokinetics of aripiprazole in patients with schizophrenia or schizoaffective disorder.

Aberrant intracellular calcium signaling in olfactory neurons from patients with bipolar disorder

OBJECTIVE

The authors examined the feasibility of using olfactory receptor neurons from living patients to test whether calcium signaling is altered in a neuronal cell population in bipolar disorder.

METHOD

Ratiometric fluorescence photomicroscopy was used to assess basal and stimulus-induced changes in intracellular calcium levels in biopsy-derived olfactory receptor neurons from seven euthymic patients with bipolar disorder who were medication-free, 10 euthymic patients with bipolar disorder who were treated with mood stabilizers, and 17 age- and sex-matched comparison subjects without bipolar disorder.

RESULTS

Olfactory receptor neurons from the seven medication-free patients responded to stimuli predominantly with decreases in intracellular calcium, unlike those from the seven matched healthy subjects. Olfactory receptor neurons from patients treated with mood stabilizers were less likely to respond to stimulation than olfactory receptor neurons from medication-free patients.

CONCLUSIONS

This study demonstrates the feasibility of using olfactory receptor neurons to examine alterations in intracellular signaling in neuronal cells from living patients. Our results, although based on a small number of subjects, suggest that altered intracellular calcium signaling in olfactory receptor neurons may be a trait of bipolar disorder.