RESUMEN
OBJECTIVE: To find the main pathologies which give rise to self-medication, the most commonly used pharmacological groups, how these drugs are obtained and the correctness of their instructions. DESIGN: Observation study of a crossover type. SETTING: An urban Health Centre. PATIENTS AND OTHER PARTICIPANTS: 396 patients, who attended during the months of February and March 1993 with requests for medication or who were already taking something, were selected at random--95% Confidence Interval with 0.049 exactness. MEASUREMENTS AND MAIN RESULTS: 76% attended when they were already taking medication, a percentage which was significantly lower among elderly people (p < 0.001). The most common pharmacological groups were analgesics (32.6%), antibiotics (19.9%) and antiflu drugs (17.6%); and the most common pathologies were respiratory conditions with or without temperature (26.2% and 32.3% respectively). Self-medication was correct in 75.5% of cases. It was least correct for antibiotics and vitamins and in descriptions of asthenia, where, in turn, demand was more frequent than self-consumption (p < 0.001). The main reason for taking medication was its previous medical prescription (38.64%). CONCLUSIONS: Patients correctly use the commonest medicines used in primary care, especially if they have been prescribed before. This suggests the importance of daily health education for each prescription, especially for the most common pathologies.