RESUMO
BACKGROUND: The aim of the present trial was to evaluate the efficacy of a combined product in the treatment of common cold and to examine the contribution of the separate components. In the published literature there is conflicting data on the efficacy of agents used in the treatment of common cold, especially when given in drug combinations. METHODS: A prospective, randomized, double-blind, multicenter, 4-arm, controlled trial was carried out in 1,167 patients with common cold treated with one of the following medications: Grippostad-C, a combination of acetaminophen, caffeine, chlorpheniramine and ascorbic acid (verum), ascorbic acid (control), chlorpheniramine and ascorbic acid (reference 1), as well as acetaminophen, caffeine, and ascorbic acid (reference 2). A score of common cold symptoms (headache, throat pain, extremities and joint pain, cough, blocked nose, and disturbances of sleep quality) was the primary outcome. The test drug was first compared with the control using a hierarchic test strategy, then with reference 1, followed by reference 2 with the aim of proving superiority. FINDINGS: A clinically relevant and statistically significant difference was demonstrated at each level of the hierarchy. Grippostad-C was significantly superior to all other treatment groups, the combination of acetaminophen, caffeine, and ascorbic acid was significantly superior to the control, and the combination of chlorpheniramine and ascorbic acid was not statistically different from the control. INTERPRETATION: The efficacy of Grippostad-C for the treatment of common cold was proven. The findings demonstrate that the combination is superior to each of its separate components and each of the components has its own distinctive contribution to the efficacy of the combination product.