[Questionable group concept. How interchangeable are so-called analog drug preparations?].

Medical drugs are usually grouped together because they exhibit identical or similar chemical and pharmacological properties. Thus, for example, all known statins lower morbidity and mortality in coronary patients. In the meantime, three beta blockers have been shown to have a life-prolonging effect in mild-to-moderate cardiac insufficiency. The question is: to what extent are the preparations interchangeable? The beta blockers in particular manifest numerous other properties--such as beta 1 selectivity, vasodilatory or antioxidative actions which, under certain circumstances may even be decisive for the success or failure of treatment. The mortality-lowering effect of high-dose ACE inhibitors in patients with a high cardiovascular risk has to date, been shown only for a single preparation. For others, the high dose (effect) has yet to be confirmed. Also, with every new substance, a new side effect profile is introduced, which may result from the tiniest alteration to the active agent molecule, but also by a different preparation method. In consequence, unexpected effects, such as allergic reactions, may occur. This not only makes the grouping of similar substances, but also the interchange of "me-too" or generic preparations, problematic.