WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• Knowledge of prescription patterns in primary health care is an important tool in rational drug therapy.• Age and gender are the principal determining factors of cost variability between medical practices, due to drug prescriptions. • Age and gender are the principal determining factors of cost variability in relation to the therapeutic group. WHAT THIS STUDY ADDS• This study provides specific information on the use of drugs in the primary health care environment of the Catalan Health System, and the differences observed are analyzed with respect to age and gender of the population receiving care.• The study shows that there is a high prevalence of drugs in the under 5 year old age group, and also in persons over 54 years of age.• The variability found in the cost per patient suggests that adjustment should be made for age in practitioners' prescription evaluation procedures in primary health care in Catalonia. AIMSTo determine the prevalence and usage patterns of prescription drugs according to patients' age and gender, and to identify their relative importance in the prescription costs, in primary health care within the Catalan Health Institute. METHODSThis was a cross-sectional study using computerized pharmacy dispensing records for 5 474 274 members registered, during 2002. Twenty age-gender categories were established. Use of a drug group was defined as filling at least one prescription. The variables studied were age, gender, number of prescriptions and net cost. The prevalence of use, the number of prescriptions and cost issued to each age category were reported. RESULTSThe overall prevalence of drug use was 74.53% (women 80.93%, men 67.84%). This was higher in the group of 0-4 year-olds, and in the Ն55 year-olds. Age (P < 0.001) produced a statistically more significant effect than gender (P < 0.05).The most used therapeutic groups were analgesics, nonsteroidal anti-inflammatory drugs, antiulcer drugs, anxiolytics, expectorants and mucolytics. The number of prescriptions and costs per patient rose with age and showed great variation in the use of these groups for patients in different age groups. The risk of prescription in women was 23% higher than in men (RR 1.23, 95% CI 1.11, 1.37, P < 0.001). CONCLUSIONSThe majority of subjects were exposed to one or more drugs. The variability in the number of prescriptions and in the prescribing cost per patient between the different age groups suggests that adjustments should be made for age in practitioners' prescription evaluation processes in primary health care in Catalonia.

This study confirms the importance of analyzing the return of unwanted medicines to reduce unnecessary health expenditure. It also highlights the inadequacies of the Spanish health system in the areas of prescription, dispensing and use of medicines. Establishing strategies to reduce the wastage of unused medicines is necessary.

This work describes two high-performance liquid chromatographic methods for the individual determination of bisoprolol and metoprolol in human plasma. Analytical methods involve two different liquid-liquid extractions of human plasma, with diethyl ether for bisoprolol and with dichloromethane for metoprolol, coupled with a similar Nucleosil C(18) reversed-phase HPLC column. Fluorimetric detection was used to identify both beta-blockers. Retention times for bisoprolol and metoprolol were 8.7 and 3.2 min, respectively. Linear regressions for the calibration curves were linear at a concentration range of 6.25-200 ng/mL. Intra- and inter-day precision coefficients of variations and accuracy bias were acceptable (within 15%) over the entire range for both drugs. Average recovery was 89% for metoprolol and 98% for bisoprolol. Once the methods had been validated, analytical error functions were established as standard deviation (SD; ng/mL) = 2.216 + 3.608 x 10(-4)C(2) (C = theoretical concentration value) and SD-(ng/mL) = 0.408 + 0.378 x 10(-1)C for bisoprolol and metoprolol, respectively. The methods developed and their associated analytical error functions will be suitable for pharmacokinetic studies and for determination of plasma concentration if posology individualization of these drugs is needed.

The pharmacokinetics of ricobendazole (RBZ) and its major metabolite albendazole sulphone (ABZSO2) were studied in six calves, after administration of RBZ (7.5 mg/kg), using a 10% experimental solution by the intravenous (i.v.) route, a 10% commercial solution by the subcutaneous (s.c.) route, and a 10% experimental suspension by the intraruminal (i.r.) route. Blood samples were drawn during a 60-h period. Plasma drug and metabolite concentrations were determined by HPLC. The pharmacokinetic evaluation in each case was prepared by weighted least-squares nonlinear regression analysis. Ricobendazole i.v. data were best fitted by a two-compartment model. The best pharmacokinetic exponents and coefficients were estimated, and the pharmacokinetic variables for RBZ and ABZSO2 were calculated from them. Similar patterns of plasma disposition were found for RBZ after i.r. and s.c. administration, suggesting delayed release from the s.c. site resembling the slow release of the drug from the rumen.

Older people usually present with adverse drug events (ADEs) with nonspecific symptoms such as cognitive decline, recurrent falls, reduced mobility, and/or major deterioration. The aims of this study were to assess the ADEs of patients with dementia and presenting neuropsychiatric/behavioral, and psychological symptoms in dementia (BPSD) and to categorize and identify the principal factors that allow to prevent ADEs, and separately ADEs that result in falls. To that end, a one-year prospective study in a psychogeriatric ward (July 2015 to July 2016) was performed. All patients admitted to this ward were eligible for enrolment. Patients who met any of the following criteria were excluded from the study: Patients without cognitive impairment, a length of stay under 7 days, and palliative or previous psychiatric pathology. We included 65 patients (60% women, 84.9 years ± 6.7) with mild to moderate cognitive impairment, moderate to severe functional dependence, and a high prevalence of geriatric syndromes and comorbidity. A total of 87.7% were taking five or more drugs (mean 9.0 ± 3.1). ADEs were identified during the interdisciplinary meeting and the follow up by clinical record. Sixty-eight ADEs (81.5% patients) were identified, of which 73.5% were not related to falls. From these, 80% were related to drugs of the nervous system. The Naranjo algorithm determined that 90% of ADEs were probable. The severity of the ADEs was Category E in 34 patients (68%). The number of preventable ADE according to the Schumork–Thornton test was 58%. The main ADE was drowsiness/somnolence (27.7%). ADEs related to falls represented a 26.5%. The balance between effective treatment and safety is complex in these patients. A medication review in interdisciplinary teams is an essential component to optimize safety prevention.