Richelson E
Mayo Clin Proc. 1983 Jan;58(1):40-6.
Tricyclic antidepressants (for example, amitriptyline) and other types of antidepressants (for example, amoxapine and maprotiline) are competitive antagonists of muscarinic acetylcholine receptors, the predominant class of acetylcholine receptors in the brain. Some evidence suggests that this muscarinic receptor blockade in brain alleviates depression. However, all tricyclic antidepressants appear to be equally effective in treating depression despite having differences in their antimuscarinic potencies while having similar ranges of therapeutic blood levels. It is more likely that the antimuscarinic potency of antidepressants is related mainly to the frequency with which they cause such symptoms as blurred vision, dry mouth, and urinary retention. Information on the antimuscarinic potency and other receptor-blocking potencies of antidepressant agents can be helpful in minimizing or avoiding certain side effects when these drugs are given to patients.
三环类抗抑郁药（如阿米替林）和其他类型的抗抑郁药（如阿莫沙平与马普替林）是毒蕈碱型乙酰胆碱受体的竞争性拮抗剂，毒蕈碱型乙酰胆碱受体是大脑中主要的乙酰胆碱受体类型。一些证据表明，大脑中的这种毒蕈碱受体阻滞可缓解抑郁。然而，尽管所有三环类抗抑郁药的抗毒蕈碱效力存在差异，但在治疗抑郁方面似乎同样有效，且它们的治疗血药浓度范围相似。更有可能的是，抗抑郁药的抗毒蕈碱效力主要与其引起视力模糊、口干和尿潴留等症状的频率相关。当给患者使用这些药物时，了解抗抑郁药的抗毒蕈碱效力及其他受体阻滞效力有助于将某些副作用降至最低或避免出现这些副作用。
