Children with ADHD from both psychiatric and pediatric practices have prototypical symptoms of the disorder; high levels of comorbidity with mood, anxiety, and disruptive behavior disorders; and impairments in cognitive, interpersonal, and academic function that do not differ by ascertainment source. These findings suggest that children cared for in pediatric practice have similar levels of comorbidity and dysfunction as psychiatrically referred youth.

Clozapine (CLZ) dose-related adverse effects may be more common in children than adults, perhaps reflecting developmental pharmacokinetic (PK) differences. However, no pediatric CLZ PK data are available. Accordingly, we studied CLZ and its metabolites, norclozapine (NOR), and clozapine-N-oxide (NOX) in six youth, ages 9-16 years, with childhood onset schizophrenia (COS). At the time of the PK study, mean CLZ dose was 200 mg (3.4 mg/kg). Serum was collected during week 6 on CLZ before and 0.5-8 h after a morning dose. Serum concentrations were assayed by liquid chromatography/UV-detection. Mean concentration, area-under-the-curve (AUC), and clearance were calculated. CLZ clearance averaged 1.7 L/kg-h. NOR concentrations (410) exceeded CLZ (289) and NOX (63 ng/ml) and AUC(0-8h) of NOR (3,356) > CLZ (2,359) > NOX (559 ng/ml-h) [53, 38, and 9% of total analytes, respectively]. In adults, NOR serum concentrations on average are 10-25% < CLZ, differing significantly from our sample. Dose normalized concentrations of CLZ (mg/kg-d) did not vary with age and were similar to reported adult values. Clinical improvement seen in 5/6 patients correlated with serum CLZ concentrations. In addition, clinical response and total number of side effects correlated with NOR concentrations. NOR (a neuropharmacologically active metabolite) and free CLZ may contribute to the effectiveness and adverse effects in youth.

Fluconazole pharmacokinetics were evaluated for 10 volunteers with AIDS who had no clinical evidence of gastroenteritis. Single 100-mg intravenous (i.v.) and oral (p.o.) doses were administered in a randomized, crossover design. i.v. doses were delivered by a constant-rate infusion over 30 min. Serum fluconazole concentrations were measured by gas-liquid chromatography. The i.v. and p.o. studies were modelled simultaneously by iterative two-stage analysis, which provided individual parameter estimates and a population pharmacokinetic model. Median areas under the concentration-time curves for i.v. and p.o. studies did not differ (90.6 and 99.3 ,ug/ml. h, respectively). Consistent with this finding, the median fractional bioavailability was 1.1 (range, 0.45 to 1.3), comparable to those in healthy subjects. Serum pharmacokinetics in these AIDS patients were generally similar to published data for healthy volunteers. However, foliowing p.o. dosing, we observed a slightly delayed and highly variable time to maximum concentration in serum (median, 2 h; range, 15 min to 8 h). Data were well described by a linear, two-compartment pharmacokinetic model with first-order absorption and elimination. Repeated-measures analysis ofvariance found no significant differences among any of the pharmacokinetic parameters between i.v. and p.o. studies. On the basis of our findings, we suggest no change in dosage of p.o. fluconazole in patients with AIDS who show no clinical signs of enteropathy.Oral (p.o.) fluconazole is frequently administered to persons with AIDS for the treatment of commonly occurring fungal infections, including oropharyngeal and esophageal candidiasis (31) and cryptococcal meningitis (32). Frequently, AIDS patients have hypochlorhydria (23) and other physiologic and anatomic disturbances of the alimentary tract (17,22,25), although gastroenteral symptoms may be absent. Potentially, these factors could interfere with the overall absorption of p.o. administered agents, alter drug transit time, and influence efficacy (11,29).To our knowledge, the absorption of p.o. fluconazole in patients with AIDS has not been investigated. The recommended dosage of p.o. fluconazole for the treatment of fungal infections in patients with AIDS is based upon pharmacokinetic data derived from healthy volunteers (4,14,21). The objective of this study was to determine the p.o. bioavailability and pharmacokinetics of fluconazole in patients with AIDS.(Results of this investigation were presented at the VIIIth International Conference on AIDS/IIIrd STD World Congress, Amsterdam, The Netherlands, July 1992.) MATERIALS AND METHODSPatients and selection criteria. The study population consisted of ambulatory patients who were served by the Brigham and Women's Hospital and the Harvard Community Health Plan (Boston, Mass.). The study protocol was approved by the institutional review boards for human investigation of both institutions. Written informed consent was obtained from each subject.Volunteers who had AIDS (5) were eligible for the stu...

The objective of this study was to evaluate the pharmacokinetic profile of fluoxetine (FLX) and its major metabolite, norfluoxetine (NORFLX), in children and adolescent patients undergoing psychiatric treatment. Twenty-one pediatric subjects--10 children (6-12 years) and 11 adolescents (13-18 years)--were administered 20 mg FLX for 60 days, with sparse blood samples taken throughout the open-label study. Subjects contributed 168 plasma concentrations. Pharmacokinetic parameters were estimated using a mixed effects nonlinear model. Mean steady-state FLX and NORFLX of 127 ng/mL and 151 ng/mL, respectively, were achieved in children and adolescents after 4 weeks of treatment, with high between-patient variability. FLX was 2-fold higher and NORFLX was 1.7-fold higher in children relative to adolescents; however, when normalized to body weight, FLX and NORFLX were similar for both age groups. Age, body weight, body mass index, and body surface area, modeled independently as continuous variables, significantly improved the population pharmacokinetic model when evaluated as patient factors. Body weight was the covariate retained in the final model. In conclusion, children have 2-fold higher FLX and NORFLX relative to adolescents that appear to be related to indices of body size. The accumulation profile and steady-state concentrations in adolescents appear similar to those in adults.

Cabergoline may be useful for the treatment of risperidone-induced hyperprolactinemia in youth; however, further research is needed.