Anesthetic Implications of Psychoactive Drugs

December 27, 2019

In 2018, one in five adults in the United States experienced mental illness.1 Mental illnesses are marked by changes in emotion, thinking or behavior, and they entail distress and/or problems functioning in numerous contexts.2 Mental illnesses vary in severity, with more serious illnesses including major depressive disorder, schizophrenia and bipolar disorder.2 Serious mental illness may require treatment with medication and/or psychotherapy; indeed, of U.S. adults with serious mental illness, 64.1 percent received treatment in 2018.1 Physicians in all fields who care for patients with mental illness must often account for psychiatric treatment. For one, psychoactive drugs’ broad effects on central and peripheral neurotransmitters and ionic mechanisms may affect anesthesia.3 Thus, anesthesiologists are responsible for managing and closely monitoring a patient on psychoactive drugs before, during and after surgery.

The effects of anesthesia on patients taking psychoactive drugs,3 as well as the effects of psychoactive drugs on anesthesia,4 have been topics of scientific research for 40 years. Drug groups that may interfere with anesthesia include tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors (MAOIs), typical and atypical antipsychotics, mood stabilizers and benzodiazepines (BZDs).5 Before surgery, an anesthesiology practitioner will evaluate the patient’s psychoactive medication class in order to decide whether or not it must be discontinued. For example, the patient must stop taking TCAs, MAOIs and lithium either at two weeks or 24 hours before surgery.5 However, a patient can continue taking SSRIs, mood stabilizers like carbamazepine and valproate, benzodiazepines and typical and atypical antipsychotics.5 The preoperative discontinuation of psychoactive drugs must also be done strategically to avoid withdrawal symptoms.5-7 Due to the complexity of different psychoactive medications, an anesthesia professional’s preoperative assessment is vital to preventing complications.

Complications during anesthesia can arise from psychoactive drug interactions and/or withdrawal. Intraoperative interactions between anesthetic and psychoactive drugs can have harmful effects on patients’ health. For example, TCAs combined with anesthetic drugs may result in seizures and lead to a serotonergic crisis.5 TCAs also exacerbate the effects of common sympathomimetic drugs (i.e., stimulants such as ephedrine and metaraminol) used by an anesthesiologist, which can lead to hypertensive crises during surgery.5 However, one study did not recommend discontinuation of TCAs before anesthesia administration.8 In patients who are taking lithium, non-steroidal anti-inflammatory drugs (NSAIDs) can increase blood lithium levels up to 40 percent, resulting in toxicity.6 Antipsychotic drugs can make patients with schizophrenia more susceptible to anesthesia-induced hypotension,9 and one case study reported exaggerated hypotension in a pregnant woman using antipsychotics along with a spinal anesthetic.10 Another study found that antipsychotic treatment enhances hypothermia during surgery.11 Meanwhile, MAOIs can affect the metabolism of anesthetic drugs, such as barbiturates, which may have implications for dosage.6 It is the responsibility of the anesthesia provider to prevent potential interactions of psychoactive medications with anesthetic drugs.

The ubiquity of mental illness and psychoactive medication management makes it necessary for all physicians to adapt patient care. Particularly, anesthesiologists must assess a patient’s use of psychoactive drugs, make recommendations to avoid abrupt withdrawal and prevent drug interactions during surgery. The anesthesia provider is crucial in balancing the patient’s mental health and the physical complications that could arise perioperatively.

1.         National Alliance on Mental Illness. Mental Health By The Numbers. Learn More September 2019;

2.         Parekh R. What Is Mental Illness? August 2018;

3.         Janowsky EC, Risch C, Janowsky DS. Effects of anesthesia on patients taking psychotropic drugs. Journal of Clinical Psychopharmacology. 1981;1(1):14–20.

4.         Kudoh A, Kimura F, Murakawa T, Ishihara H, Matsuki A. Perioperative management of patients on long-term administration of psychotropic drugs. Masui. 1993;42(7):1056–1064.

5.         Peck T, Wong A, Norman E. Anaesthetic implications of psychoactive drugs. Continuing Education in Anaesthesia Critical Care & Pain. 2010;10(6):177–181.

6.         Attri JP, Bala N, Chatrath V. Psychiatric patient and anaesthesia. Indian Journal of Anaesthesia. 2012;56(1):8–13.

7.         Huyse FJ, Touw DJ, Van Schijndel RS, de Lange JJ, Slaets JPJ. Psychotropic Drugs and the Perioperative Period: A Proposal for a Guideline in Elective Surgery. Psychosomatics. 2006;47(1):8–22.

8.         Kudoh A, Katagai H, Takazawa T. Antidepressant treatment for chronic depressed patients should not be discontinued prior to anesthesia. Canadian Journal of Anesthesia. 2002;49(2):132–136.

9.         Kudoh A. Perioperative Management for Chronic Schizophrenic Patients. Anesthesia & Analgesia. 2005;101(6):1867–1872.

10.       Williams JH, Hepner DL. Risperidone and Exaggerated Hypotension During a Spinal Anesthetic. Anesthesia & Analgesia. 2004;98(1):240–241.

11.       Kudoh A, Takase H, Takazawa T. Chronic Treatment with Antipsychotics Enhances Intraoperative Core Hypothermia. Anesthesia & Analgesia. 2004;98(1):111–115.