When are drug combinations justified?

Abstract

Drug combinations contain two or more active ingredients in fixed doses in a single preparation; the dose-ratio is determined by the manufacturer. Among over 240 preparations on the World Health Organisation’s model list of ‘essential’ drugs, there are only 7 drug combinations - less than 3%.1 By contrast, of more than 2, 2000 branded drug products listed in MIMS,2 nearly half are fixed-ratio combinations, although the proportion varies widely between therapeutic groups - 10% for metabolic disease, 70% for respiratory and gastro-intestinal conditions.3 More than one-third of all new drug products introduced world-wide in 1978 were combinations.4