Reliability of 3 sources of information about medication excipients

OBJECTIVE To find how reliably three sources of therapeutic information record the composition of excipients: the Vademecum, the pharmaceutical catalogue and the instructions sheets of pharmaceutical products. DESIGN Descriptive study. SETTING Primary care. PATIENTS AND OTHER PARTICIPANTS Initially, 658 orally-taken products were selected. Whether four excipients (saccharine, saccharose, lactose and ethanol) appeared in these products' composition formulas was compared. RESULTS In 70.6% +/- 5.11 there was discordance on the excipients in the composition formulas in one of the three sources of therapeutic information. The instructions sheets contained information on the number of excipients in 98.7% +/- 1.3 of the products, the pharmaceutical catalogue in 87.2% +/- 3.7 and the Vademecum in 65.7% +/- 5.3. So the Vademecum was the source of therapeutic information containing the highest percentage of products with no kind of information about excipients, followed by the catalogue and the instructions sheets. The instructions sheets were the best source of therapeutic information for 289 products. 10.3% of laboratories did not quantify their excipients in any of the three sources under study. CONCLUSIONS The Vademecum and pharmaceutical catalogue do not include very reliable information about these four excipients in the composition formulas of pharmaceutical products. It is important to make available to doctors straightforward texts which provide more reliable and up-to-date information.