Paradoxical pharmacology: turning our pharmacological models upside down.

Paradoxical pharmacology is a term first suggested by Richard Bond to refer to intriguing observations that chronic use of some drug types can have the opposite biological effect(s) to those seen following acute administration of the same drug. A good example of 'paradoxical pharmacology' is the research Richard has pioneered showing that whereas acute administration of β-blockers is contraindicated in the treatment of asthma, chronic use of certain β-blockers can have therapeutic benefit. It would appear that those β-blockers that can act as inverse agonists at the β2 receptor particularly show this paradoxical effect and the findings of Richard's research not only challenge the dogma of the treatment of asthma but also challenge many of the pharmacological principles of ligand/receptor interactions established by Sir James Black and others. In this paper, I discuss Richard's efforts to evaluate the chronic effects of β-blockers in the airways and how this research caught the imagination of Sir James Black.