Anesthetic Considerations for Patients on Antidepressant Therapy – Part II

Abstract

Millions of patients take antidepressant medications in the United States for the treatment of depression or anxiety disorders. Some antidepressants are prescribed off-label to treat problems such as chronic pain, low energy, and menstrual symptoms. Antidepressants are a broad and expansive group of medications, but the more common drug classes include tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and monoamine oxidase inhibitors. A miscellaneous or "atypical" category covers other agents. Some herbal supplements that claim to have antidepressant activity will also be discussed. Part I of this series reviewed antidepressant pharmacology, adverse effects, and drug interactions with adrenergic agonists. In part II, drug-drug interactions with sedation and general anesthetics, bleeding effects, and serotonin syndrome will be discussed.

Expectant management of a parturient with serotonin syndrome: A case report

“…6 The presence of any one of the clinical features (spontaneous clonus; inducible or ocular clonus with agitation or diaphoresis; tremor and hyperreflexia; or hypertonia and febrile) along with history of serotoninergic agent administration in the last five weeks meet criteria for SS. 1 , 6 Anticholinergic poisoning, malignant hyperthermia, neuroleptic malignant syndrome, pheochromocytoma, thyrotoxicosis, as well as drug withdrawal share many of the characteristics of SS, so a thorough patient history is needed to narrow this differential diagnosis. 2 Additionally, ruling out pre-eclampsia in acute SS may prove particularly challenging.…”

“…Severe cases may require short acting vasoactive agents for autonomic instability, cooling, muscle relaxation, endotracheal intubation and mechanical ventilation for myoclonus and hyperthermia, and cyproheptadine therapy, a 5-HT 1A and 5-HT 2A antagonist antihistamine with weak anticholinergic activity. 1…”

“…Serotonin syndrome is caused by serotonin excess in the central nervous system, most frequently resulting from supratherapeutic antidepressant dosing and drug-drug interactions. 1 Rarely described in the obstetric population, the overall incidence of serotonin syndrome has been reported to be as high as 0.4 cases per 1000 patient-months of antidepressant treatment. 2…”

Manejo perioperatorio de nuevos fármacos psiquiátricos

“…Un efecto adverso que con frecuencia se menciona, relacionado al uso de antidepresivos que aumentan la disponibilidad de serotonina, es el síndrome serotoninérgico. Esto es provocado por un aumento excesivo en los niveles de serotonina en el sistema nervioso central, que puede ocurrir con dosis terapéuticas de estas drogas, pero con mayor frecuencia se asocia a sobredosis o interacciones de drogas que determinan sinergismo en la actividad serotoninérgica [6], [7]. Este se manifiesta con la tríada de inestabilidad autonómica, alteraciones neuromusculares y cambios en el estado mental del paciente.…”

“…Al igual que lo que podía ocurrir con los antidepresivos tricíclicos, al ser fármacos que aumentan la disponibilidad de noradrenalina, asociado a algunos agonistas adrenérgicos en el perioperatorio, se han descrito casos de aumentos relevantes de la presión arterial y la frecuencia cardíaca, pero los eventos en general son poco frecuentes y autolimitados. Venlafaxina y duloxetina son inhibidores del citocromo P450, específicamente CYP 2D6 [7], los que podrían determinar alteraciones de la cinética de algunos fármacos, por otro lado, desvenlafaxina no cuenta con este efecto adverso. En suma, no se han reportado grandes efectos adversos de estas drogas en el perioperatorio, por lo que la recomendación general es mantenerlas.…”