[The impact of hospitalization on drug prescription]

The aim of this study was to investigate the influence of hospitalization on drug prescription and identify the proportion of hospital admissions for "pharmacologic causes" and the incidence of side effects during hospital stay.

Five hundred four patients admitted to the internal medicine department of a community hospital over a consecutive six-month period were studied. Follow up until hospital discharge was carried out with information being collected according to a protocol established from the characteristics of the treatment administered.

Most of the patients admitted were elderly males, with low educational and socioeconomic status, presenting multiple chronic diseases. During hospitalization the number of drugs prescribed doubled (6.0) in relation to the mean (3.3) at the time of admission. Upon discharge the mean number of drugs prescribed (4.1) was significantly higher to that at the time of patient admission. This increase in the number of drugs prescribed upon discharge reflected practically all of the therapeutic groups, specially those of antibiotics, hematologic and digestive drugs, including all the patients regardless of age or sex. The number of drugs prescribed during admission was identified as a variable independently associated to the increase in the number of drugs prescribed on discharge. Hospital admissions for pharmacologic causes were due to therapeutic non compliance (15.4%) and the presentation of side effects (7.8%). The presentation of side effects during hospitalization (8.5%), mostly gastrointestinal, cardiovascular or neurologic was related with age, and the number of drugs administered, and was associated with longer hospital stay.

Contrary to what was expected, hospitalization leads to an increase in the number of drugs prescribed in relation with the therapeutic schedules administered prior to admission.