ABSTRACT
Substances that mimic the ligand and bind but produce no effect are called antagonists. They have been considered earlier and reference should be made to this section for their use as drugs (see Table 19.8 and Figures 19.24 and 19.25). The theory of drug-receptor action is described in ‘Graded dose response curves’ (see Figure 19.18). Most drug-receptor combinations are rapidly reversible. An example of an exception is phenoxybenzamine.
