Many drugs exert their effects through modulation of cAMP pathways. For example, beta-adrenergic agonists increase cAMP levels, resulting in bronchodilation and increased cardiac output. However, excessive stimulation of these pathways can lead to toxicity, such as arrhythmias. Moreover, drugs like theophylline, a phosphodiesterase inhibitor, prevent the breakdown of cAMP, leading to elevated levels that can cause gastrointestinal disturbances and CNS stimulation if overdosed.
