Background Health centres have many opportunities to improve community health. One of them is to give information among drug users about the adulterants of the substances that they will consume with the purpose of avoiding acute reactions to consumption

Purpose To know the main adulterants of intravenous samples and their effects among users of injected drugs.

Materials and methods Survey among active intravenous drugs users in Barcelona. Several drugs users were trained to interview other drugs users who did not use social and health services. The authors collected socioeconomic and consumption data and the users were asked to give a part of their samples to be analysed before their intravenous consumption.

Results Data from 63 men and 31 women were collected. 70 of them use cocaine, and 76 use heroin. Both substances alone or mixed. 69 were injecting drug users. 17 samples can be analysed. The additive substances found in cocaine samples were caffeine, lidocaine, procaine, phenacetine, tetracaine and levamisol; paracetamol and caffeine in heroin samples

Conclusions Studies of Hospital Services can be involved in real street research. In this study The authors reviewed proceedings of a high morbidity such as illicit drug consumption. The knowledge of main adulterants of intravenous samples enables us to study effects and interactions, to achieve the best healthcare and to develop educational programs among drug users.