The top-selling drug products: how good are they?

The hypothesis that the most frequently prescribed drugs are clinically superior to existing competitive products was tested. The 200 drug preparations most frequently dispensed in community pharmacies, covering 163 separate drug entities, were rated for therapeutic acceptability by using 10 independent indicators, five of positive opinion and five of negative opinion. Less than 47% of the drug entities satisfied the criterion of clinical superiority. At least 25% apparently should be excluded altogether as drugs of choice. Within the limitations of the study model, the results indicate that a given drug's popularity among prescribers is not related to clinical superiority of the product.