Question

speak about complementarity in the drug-drug target binding

Answer 1

In drug-drug binding, one drug must be complementary in shape and charge to the another target drug with which they interacts and therefore will bind to it. The drug binding to target active sites requires physicochemical and steric complementarity. The orientation of one molecule or drug must be complementary to the second one.

Drug-drug binding can be through different interactions such as covalent, or non-covalent interactions. Drug-drug binding complex may have entirely different properties from that of the two respective drugs.