An observational study in Chronic SSRI/SNRI Use and Intraoperative Propofol Requirements, sponsored by Kocaeli City Hospital. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-30.
Sponsored by Kocaeli City Hospital · Observational
The goal of this observational study is to learn whether long-term use of selective serotonin reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressants is related to the amount of propofol needed during planned spine surgery. Propofol is a medicine given through a vein to produce and maintain anesthesia.
The main questions this study aims to answer are:
The study will include 216 adults undergoing planned spine surgery. Researchers will compare 108 participants who regularly take an SSRI or SNRI with 108 participants who do not take these medicines.
All participants will receive routine anesthesia care. The study will not start, stop, or change any antidepressant treatment, and participants will not be randomly assigned to a group. Researchers will record the amount of propofol and remifentanil used during surgery, blood pressure, heart rate, oxygen level, depth of anesthesia, and recovery time.
Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are considered first-line pharmacological agents in the treatment of depression and anxiety disorders (1). These drugs selectively increase serotonin concentrations in the synaptic cleft by inhibiting the serotonin transporter (SERT); they suppress norepinephrine and dopamine reuptake only minimally (1). However, SSRI and SNRI agents have the potential to cause hypertensive effects (2). The hypertensive mechanism is associated with SSRIs raising synaptic serotonin levels through SERT inhibition, resulting in overstimulation of 5-HT1A and 5-HT2A receptors (3). Serotonin excess activates the sympathetic nervous system, triggering vasoconstriction, tachycardia, and catecholamine release, leading to an increase in blood pressure; this indirectly increases the need for intraoperative anesthetic (4). Additionally, SSRIs-especially potent CYP2D6 inhibitors such as paroxetine and fluoxetine-can reduce the analgesic effects of prodrug-type opioids (e.g., codeine, hydrocodone, and tramadol) by inhibiting their metabolism (5). This interaction blocks the conversion of prodrugs to active metabolites (codeine → morphine; hydrocodone → hydromorphone) via the CYP2D6 enzyme in the liver, reducing plasma active opioid concentrations and disrupting μ-opioid receptor activation; ultimately leading to a higher opioid dose requirement for patients (5). As a parallel mechanism, serotonin excess (at high doses or in interaction with other agents) can induce serotonin-induced hyperalgesia; this process occurs through stimulation of the cAMP secondary messenger system via 5-HT1A receptors in peripheral nerve endings and potentiates the tendency towards hyperalgesia (6). Considering these described mechanisms, maintaining a constant remifentanil dose during the intraoperative period may increase propofol consumption (7). However, despite this theoretical information, the effect of SSRI-SNRI use on propofol consumption during the perioperative period has not been sufficiently investigated. Therefore, this study will investigate the relationship between these two factors.
Kocaeli City Hospital is the lead sponsor of 44 studies on the registry; 19 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population will be drawn from patients scheduled for elective spine surgery at Kocaeli City Hospital in Kocaeli, Türkiye. Potential participants will be identified during routine preoperative evaluations in the anesthesia clinic or relevant inpatient surgical wards before surgery.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receiving chronic selective serotonin reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI) therapy before elective spine surgery. These medications will not be initiated, discontinued, or modified for study purposes. Intraoperative propofol consumption and prespecified perioperative outcomes will be recorded.
Adults undergoing elective spine surgery who are not receiving chronic SSRI or SNRI therapy and are not using antipsychotic or other antidepressant medications. Participants will receive routine BIS-guided total intravenous anesthesia with propofol and remifentanil. No study-specific intervention will be administered. Perioperative variables and total anesthetic drug consumption will be recorded.
Total Intraoperative Propofol Consumption
The total cumulative dose of propofol administered during anesthetic induction and BIS-guided total intravenous anesthesia maintenance will be recorded in milligrams (mg) for each participant. Total propofol consumption will be compared between participants receiving chronic SSRI/SNRI therapy and control participants.
Time frame: From induction of anesthesia until the end of surgery, on the day of surgery
Total Intraoperative Remifentanil Consumption
The total cumulative dose of remifentanil administered during total intravenous anesthesia will be recorded in micrograms (µg) for each participant and compared between the study groups.
Time frame: From induction of anesthesia until the end of surgery, on the day of surgery
Difference in Total Intraoperative Propofol Consumption Between the SSRI and SNRI Groups
Total intraoperative propofol consumption, measured in milligrams (mg), will be compared between participants receiving chronic selective serotonin reuptake inhibitor (SSRI) therapy and those receiving chronic serotonin-norepinephrine reuptake inhibitor (SNRI) therapy.
Time frame: From induction of anesthesia to the end of surgery
Plan to share: No — Individual participant data are not planned to be shared with external researchers because the approved protocol and informed consent process do not include external sharing of individual-level data. Study findings will be reported only in aggregate form in scientific presentations and publications to protect participant confidentiality.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Kocaeli City Hospital