Data from subjects in nine phase 1 (n ‫؍‬ 153) and six phase 2/3 (n ‫؍‬ 129) clinical trials were combined to identify factors contributing to interindividual variability in daptomycin pharmacokinetics (PK). Over 30 covariates were considered. A two-compartment model with first-order elimination provided the best fit for data on daptomycin concentrations in plasma over time. In the final population PK model, daptomycin plasma clearance (CL) was a function of renal function, body temperature, and sex. Of these factors, renal function contributed most significantly to interindividual variability. CL varied linearly with the estimated creatinine clearance. CL among dialysis subjects was approximately one-third that of healthy subjects (0.27 versus 0.81 liter/h). CL in females was 80% that in males; however, in clinical trials, the outcome was not affected by sex and therefore this effect is not considered clinically meaningful. The relationship with body temperature should be interpreted cautiously since the analysis included only a limited number of subjects who were hyperthermic. The volume of distribution of the peripheral compartment (V 2 ) and intercompartmental clearance (Q) were linearly related to body weight. V 2 increased approximately twofold in the presence of an acute infection. No factors were identified that significantly impacted V 1 . This analysis supports the dosing of daptomycin on a milligram-per-kilogram-of-body-weight basis and suggests that modified dosing regimens are indicated for patients with severe renal disease and for those undergoing dialysis. Daptomycin

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The degree to which changes in caregiver burden over a one year period can be predicted by functioning of dementia patients and caregiver psychological stress was examined. The Direct Assessment of Functional Status (DAFS) was administered to 44 patients and the Caregiver Burden Inventory and the Brief Symptom Inventory were administered to their next-of-kin caregivers. All patients and caregivers were assessed at baseline and again in approximately one year with the same measures. Hierarchical regression revealed that baseline patient functioning predicted overall changes in caregiver burden, but that increases in psychological symptoms of caregivers such as depression, anxiety and hostility were the best predictors for specific types of increased caregiver burden, such as social, developmental, or physical burden. These results suggest that interventions should target reduction of particular psychological symptoms in order to reduce caregiver burden over time.

Acute onset of psychosis in an older or elderly individual without history of previous psychiatric disorders should prompt a thorough workup for neurologic causes of psychiatric symptoms. This report compares and contrasts clinical features of new onset of psychotic symptoms between two patients, one with an acute basal ganglia hemorrhagic stroke and another with an acute mid-brain ischemic stroke. Delusions and hallucinations due to basal ganglia lesions are theorized to develop as a result of frontal lobe dysfunction causing impairment of reality checking pathways in the brain, while visual hallucinations due to mid-brain lesions are theorized to develop due to dysregulation of inhibitory control of the ponto-geniculate-occipital system. Psychotic symptoms occurring due to stroke demonstrate varied clinical characteristics that depend on the location of the stroke within the brain. Treatment with antipsychotic medications may provide symptomatic relief.