[Adverse reactions to drugs in a health center]

To study the adverse side-effects to medication and define their principle characteristics.

A descriptive, crossover, observation study with no random distribution.

The population cared for at a Health Centre in Toledo.

Those over 15 years old during a 6-month period.

64 adverse side-effects were detected, classified as follows: definite, 10.9%; probable, 68.7%; possible, 20.3%. The rate of adverse side-effects was 2.67 per thousand prescriptions and 2.22 per thousand consultations. Distribution by gender was 62.5% women and 37.5% men. The 35-45 age group was the one with most adverse side-effects. The most affected systems were the digestive apparatus (46.50%), followed by the nervous system (27.50%) and the skin (16.22%). The most commonly involved pharmacological groups were: analgesics and non-steroid anti-inflammatories (34.37%) and drugs for the cardiovascular system (26.56%). 98.43% were trivial and none serious. Evolution was: 59.37% recovered on stopping the drug and 23.43% with the help of treatment.

The number of suspected adverse side-effects in the Centre is high, but they were trivial. It was confirmed that adverse side-effects suppose a frequent medical problem in Primary Care. It is important to make health professionals aware so that, when prescribing, they bear in mind the drug risk/benefit relationship. The identification and communication of adverse side-effects, especially of medicines newly on the market, is also important.