Torrico Tyler, Kahlon Angad
Kern Medical, Department of Psychiatry, Bakersfield, CA, United States.
American Psychiatric Association Substance Abuse and Mental Health Services Administration (SAMHSA) Minority Fellowship, Washington, DC, United States.
Front Psychiatry. 2023 Jul 13;14:1185750. doi: 10.3389/fpsyt.2023.1185750. eCollection 2023.
Among antipsychotics, sialorrhea is most associated with clozapine, and when it occurs, it is uncomfortable, socially stigmatizing, and can contribute to medication non-adherence. Risperidone has a generally negligible muscarinic activity compared to clozapine, and yet, multiple reports of severe sialorrhea associated with risperidone have been reported.
This case report describes risperidone-induced sialorrhea that was unintentionally masked by simultaneous clonidine administration that was intended to treat hypertension. Interestingly, sialorrhea was present but mild when clonidine was present; however, when risperidone was further titrated and clonidine removed, a significant worsening of sialorrhea developed. Sialorrhea did not respond to treatment with anticholinergic medication.
The pathophysiology of antipsychotic-induced sialorrhea is complex and varies between antipsychotics. Risperidone-induced sialorrhea is suspected of having prominent adrenergic pathophysiology that is likely composed of highly viscoelastic saliva (high protein content), differing from the more commonly encountered clozapine-induced sialorrhea. Risperidone-induced sialorrhea is reported as more likely to respond to dose reduction and treatment with α2-adrenergic receptor agonists or β-adrenergic receptor antagonists and less likely to respond to anticholinergic (antimuscarinic) medications.
在抗精神病药物中，流涎症与氯氮平的关联最为密切，一旦出现，会让人感到不适，带来社会污名化，还可能导致药物治疗依从性下降。与氯氮平相比，利培酮的毒蕈碱活性通常可忽略不计，然而，已有多例与利培酮相关的严重流涎症报告。
本病例报告描述了利培酮引起的流涎症，因同时服用用于治疗高血压的可乐定而被意外掩盖。有趣的是，在服用可乐定时流涎症存在但较轻；然而，当进一步滴定利培酮并停用可乐定时，流涎症显著恶化。流涎症对抗胆碱能药物治疗无反应。
抗精神病药物引起的流涎症的病理生理学很复杂，且因抗精神病药物而异。利培酮引起的流涎症被怀疑具有突出的肾上腺素能病理生理学，可能由高粘弹性唾液（高蛋白含量）组成，这与更常见的氯氮平引起的流涎症不同。据报道，利培酮引起的流涎症更可能对剂量减少以及使用α2肾上腺素能受体激动剂或β肾上腺素能受体拮抗剂治疗有反应，而对抗胆碱能（抗毒蕈碱）药物反应较小。
