Co- and multimedication in users of ASA and vitamin E drugs in the Federal Republic of Germany. Results of the Federal Health Surveys 1984-1999.

Objective: Because ASA- and vitamin E-drugs belong to the most used OTC-medications and adverse drug reactions are depending on the quantity and type of comedication we describe the pattern of usage for ASA- and vitamin E-drugs along with the total drug consumption in Germany. STUDY POPULATION, MATERIAL AND METHODS: Study participants (n = 22.560) were screened in five German health surveys (1984-1999). Total drug usage was monitored with a standardized questionnaire. Blood and serum samples were examined for clinical chemistry and hematological data as well as for selected active substances of drugs. The tocopherols and salicylic acid as the main metabolite of ASA were measured by HPLC in serum samples.

Results: The incidence of OTC-drug usage is high in our population. The salicylic acid concentration in the serum samples depends clearly on the reason of usage and remains fairly stable for analgesic use but decreases steadily from 1984 to 1999 for use as antiplatelet drug due to formulations with lower amount of ASA/tablet. The serum concentration of alpha-tocopherol was steadily increasing in users of vitamin E-drugs as well as in no-drug-users.

Conclusion: Because the frequency of comedication is very high, the risk of adverse drug reactions seems to be a problem that should be considered more seriously by physicians.