Determinations of single serum drug concentrations are useful in monitoring drug therapy. A mean serum level would supply more information but is expensive and laborious because of the multiple blood samples and assays, calculation of area under the curve (AUC) by the trapezoidal rule, and division of the AUC by the time interval during which the samples were drawn. A method was devised that pools aliquots from individual serum samples taken during the testing period to form on composite sample. A single assay of this sample provides the mean serum level of the testing period. The method was successfully tested with amaranth and then applied to valproic acid serum levels. AUC and mean serum levels were determined by the standard procedure of assays of multiple samples and the trapezoidal rule. Mean serum level was also determined by the pooled sample technique. The correlation coefficient for the comparison of the mean serum levels determined by the two techniques is 0.907 (p less than 0.001). There was no difference between the estimates of the mean serum levels by Student's paired t test (t = 0.693, p greater than 0.2). The good correlation and lack of difference between the conventional method and the pooled sample method indicates that the method is valid.

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Objectives. This study evaluated the effectiveness of a medication reconciliation program conducted by doctor of pharmacy (PharmD) students during an advanced pharmacy practice experience. Methods. Patients admitted to medicine or surgery units at 3 hospitals were included. Students were instructed to interview each patient to obtain a medication history, reconcile this list with the medical chart, and identify and solve drug-related problems. Results. Eleven students reconciled medications for 330 patients over 10 months and identified 922 discrepancies. The median number of discrepancies found per patient was 2, and no discrepancies were found in 25% of the cases. In cases in which discrepancies were identified, a greater number of medications had been prescribed for the patient (7.9 6 4.0 medications compared to 5.4 6 3.9 medications; p , 0.05). The students completed 59 interventions. Differences were found in the numbers of discrepancies and drug-related problems that different students at different sites identified (p , 0.05). Conclusions. Pharmacy students provided a valuable service to 3 community hospitals. The students improved the quality of patient care by identifying and solving significant drug-related problems, identifying drug allergy information, and resolving home and admission medication discrepancies.

In order to compare the relative bioavailability of orally administered methotrexate (MTX) with i.m. administration in patients with rheumatoid arthritis, we compared the pharmacokinetics of MTX at both the usual starting dose of 7.5 mg and at higher established maintenance dosages in 21 patients. Pharmacokinetic measures were repeated approximately 6 and 18 months after baseline while patients consumed their usual maintenance doses of MTX (17.0 +/- 3.8 mg). The relative bioavailability of the usual maintenance dose of MTX was reduced by 13.5% compared with the initial dose of 7.5 mg (P = 0.026). Area under the serum concentration vs time curve (AUC) was significantly reduced with oral vs i.m. administration at usual maintenance doses (decrease of 0.729 mumol.h/l by oral administration, P = 0.027), but not at a 7.5 mg dose of MTX. Clinicians using MTX should not assume constant and complete bioavailability across the dose range used to treat patients with rheumatoid arthritis. Our observations explain the reported clinical success of switching from an oral to a parenteral route of administration in patients receiving maintenance doses of MTX.

A home-based pharmaceutical care model for recently hospitalized patients with heart failure did not significantly improve the combined rate of death or rehospitalization.