The efficacy of multi-drug therapy for the common cold with particular reference to Kan Jang fixed combination
The general, and very successful, approach of oriental medicines, such as Ayurveda and Unani in India, and Kampo in China and Japan, involves treatment with complex mixtures of a number of herbs. In some cases, the medicinal value of the preparation is entirely due to the combination of constituents and cannot be reproduced by one or two so-called active principles alone. Recent research has shown that in the treatment of viral diseases, fixed combinations of plant extracts often provide greater-than-expected medicinal benefits by virtue of multiple constituents that exhibit synergistic effects and also act upon different molecular targets. KanJang® oral solution, a fixed combination of standardised extracts of Adhatoda vasica, Echinacea purpurea, and Eleutherococcus senticosus, has been available in Scandinavia for around 20 years for the relief of symptoms associated with common cold, particularly coughing and irritability of the throat [1,2]. In recent randomised, double-blind controlled clinical studies, this preparation has been shown to have a significant effect on symptoms related to uncomplicated upper respiratory tract infections (i.e. coughing, quality of sleep, mucus discharge in the respiratory tract, and nasal congestion) in comparison with placebo or with a combination of Echinacea purpurea and Eleutherococcus senticosus alone. The significance of the results obtained in these studies is discussed with respect to the efficacy of KanJang in the treatment of acute respiratory infection and to the concept that multi-drug therapy offers higher efficacy compared to mono-drug treatment of such infections.
References:  Thom E, Wollan T (1997) A controlled clinical study of Kanjang mixture in the treatment of uncomplicated upper respiratory tract infections. Phytotherapy Res 2: 207–210.  Narimanian M, M. Badalyan, V.Panosyan, E. Gabrielyan, A.Panossian, G.Wikman, and H.Wagner (2005) Clinical evidence of high efficacy of fixed combinations of herbal extracts, with particular reference to Adhatoda vasica, in patients with non-complicated respiratory tract infections (bronchitis). Phytomedicine, 12, 539–547.