Etrasimod is a sphingosine-1-phosphate (S1P) receptor modulator, indicated for the treatment of moderately to severely active ulcerative colitis (UC) in adults.
Precautions for Taking Etrasimod
Contraindications
Patients who have experienced myocardial infarction, unstable angina pectoris, stroke, transient ischemic attack (TIA), or decompensated heart failure requiring hospitalization within the past 6 months.
Patients with Mobitz type II second-degree or third-degree atrioventricular block, sick sinus syndrome, or sinoatrial block (unless the patient has a functioning cardiac pacemaker implanted).
Baseline Assessment Requirements
Blood tests: Obtain a complete blood count (including lymphocyte count) within 6 months (or after discontinuing previous UC treatment).
Cardiac assessment: Perform an electrocardiogram (ECG) to identify potential conduction abnormalities; consultation with a cardiologist is required for specific patients.
Liver function tests: Obtain transaminase and bilirubin levels within 6 months.
Ophthalmic examination: Conduct a baseline fundus examination (including assessment of the macular region).
Skin examination: Perform a skin examination before or shortly after the start of treatment.
Management of Special Risks
Infection risk: Opportunistic infections such as herpes zoster and cryptococcal meningitis may occur during treatment.
Cardiac effects: The first dose may cause a transient decrease in heart rate (average reduction of 7.2 beats per minute) and atrioventricular conduction delay.
Liver function abnormalities: Approximately 4.5% of patients experience an increase in alanine transaminase (ALT) to more than 3 times the upper limit of normal.
Macular edema: Regular fundus examinations are required, especially when visual changes occur.
Elevated blood pressure: The average systolic blood pressure may increase by 1-4 mmHg, requiring regular monitoring.
Medication Monitoring for Etrasimod
Routine Monitoring
Blood monitoring: Regularly measure lymphocyte count during treatment.
Cardiac monitoring: Closely observe changes in heart rate 2-3 hours after the first dose.
Liver function monitoring: Immediately test liver enzymes if symptoms such as nausea or jaundice occur.
Vision monitoring: Conduct regular ophthalmic examinations during treatment, with attention to changes in the macula.
Monitoring in Special Populations
Hepatic insufficiency: Use is not recommended for patients with severe hepatic impairment (Child-Pugh Class C).
Poor CYP2C9 metabolizers: Avoid concurrent use of moderate to strong inhibitors of CYP2C8 or CYP3A4.
Self-Monitoring
Instruct patients to recognize and report the following in a timely manner:
Infection symptoms (e.g., fever, fatigue).
Abnormal heart rate (e.g., palpitations, syncope).
Visual changes or new skin lesions.
Dyspnea or neurological symptoms.


