Unani concept of drug substitution (therapeutic interchange) and its validation on scientific parameters

BACKGROUND: Unani concept of therapeutic interchange, despite having immense practical aspect, has not been touched upon in a coherent way by most of the Unani scholars except Razi (Rhazes 865–925 AD), who took the concept plausibly and framed rules for alternate drug prescription at the time of unavailability of the drugs of choice. OBJECTIVE: The Unani concept of therapeutic interchange is based on similarity in action, temperament and physical properties of drugs mainly botanicals, which are already established and need no further discussion; however, phytochemistry has not been considered a basis for substitution. Therefore, objective of this study was evaluation of the concept on phytochemical parameters as actions of most drugs are due to phytoconstituents. MATERIAL AND METHODS: Classical Unani literature pertaining to therapeutic interchange and ethnobotanical literature for uses and phytoconstituents of three botanicals and their respective substitutes were reviewed. Ethnobotanical literature was collected from well known search engine viz., PubMed, Google Scholar, Scopus and Science direct. In view of exploring the concept on scientific basis, physicochemical, phytochemical and analytical (HPLC, GC–MS) studies were also conducted. RESULTS: The study exhibited similarity in phytoconstituents in main and substitute botanicals with insignificant differences. Direct relation between doses, actions, intensity of actions, temperament and chemical constituents of main and substitute botanicals was observed. CONCLUSION: The study, however, seemed to validate the concept on the basis of phytoconstituents, further pharmacological studies on the basis of properties and activities is required to strengthen the concept.