Pharmacotherapy and evolution

The therapeutic effects of a drug are the result of its action on a specific molecular target combined with the counterregulatory responses of the organism that aim to restore the affected parameters to previous values. The regulatory systems that control the steady state have evolved under natural selection, but because natural selection is a slow process and cannot foresee future developments, these systems are not always adjusted optimally to current conditions. Their activation can therefore reduce or prevent the desired effects of a drug and can even produce adverse effects. Recent examples from the treatment of obesity and arterial hypertension provide new insight to the contribution of such ancient counterregulatory responses to the therapeutic effects of modern pharmacotherapy. This widens the scope of the rapidly growing field of evolutionary medicine, because it demonstrates that evolutionary principles apply not only to the pathogenesis of human diseases, but also to their treatment.