[Weight-loss drugs: composition of diet pills prescribed in Navarra]

The prescription, dispensation and sale of "Magisterial formulas" for weight loss is a very extended practice in Spain, in spite of being strongly unadvised by different Administration Department as well as by medical and sanitary groups. The composition of these preparations is not labelled if so only in a generic way.

The content of 54 capsules from 6 different origins (3 medical consultations, 1 pharmacist consultation, 1 free sale in pharmacies and 1 free sale in stores) was analysed in 2 laboratories. The presence and quantity of 29 active principles was searched by spectrophotometry, chromatography and radioimmunoassay.

The presence of some of the 12 following substances was confirmed in 42 samples (77.8%): hormones (levothyroxine, cortisol and cortisone), appetite suppression phenetilamines (amphetamine, amphepranone, fenfluramine and fenproporex), benzodiazepines (diazepam, clorazepato and chlordiazepoxide) and diuretics (triamterene and ciclotiazide). The quantities of active principles was very variable in and among the six groups. In 13 of the capsules 1 active principle and in 29 combinations of two or more was found. None component of the labels, when available, corresponded with their analysed components. In 12 samples (22.2%) none of the which may correspond to some substances different from the 29 sought ones.

The usage of formulas as the studied here on the overweight and obesity treatment should be obviously unadvised.