Zeposia may cause serious side effects, including:
1. Infections. Zeposia can increase your risk of serious infections that can be life-threatening and cause death. Zeposia lowers the number of white blood cells (lymphocytes) in your blood. This will usually go back to normal within 3 months of stopping treatment. Your healthcare provider may do a blood test of your white blood cells before you start treatment.
Call your healthcare provider right away if you have any of the following symptoms of an infection during treatment, and for 3 months after your last dose:
fever
feeling very tired
flu-like symptoms
cough
painful and frequent urination (signs of a urinary tract infection)
rash
headache with fever, neck stiffness, sensitivity to light, nausea or confusion (these may be symptoms of meningitis, an infection of the lining around your brain and spine)
Your healthcare provider may delay starting or may stop your treatment if you have an infection.
2. Slow heart rate (also known as bradyarrhythmia) when you start taking Zeposia. Zeposia may cause your heart rate to temporarily slow down, especially during the first 8 days of treatment. You will have a test to check the electrical activity of your heart called an electrocardiogram (ECG) before you take your first dose. Call your healthcare provider if you experience the following symptoms of slow heart rate:
dizziness
lightheadedness
feeling like your heart is beating slowly or skipping beats
shortness of breath
confusion
chest pain
tiredness
Follow directions from your healthcare provider when starting treatment and when you miss a dose. See How should I take Zeposia?
See Zeposia side effects for more information about side effects.
Who should not take Zeposia?
Do not take Zeposia if you:
have had a heart attack, chest pain (unstable angina), stroke or mini-stroke (transient ischemic attack or TIA), or certain types of heart failure in the last 6 months.
have or have had a history of certain types of an irregular or abnormal heartbeat (arrhythmia) that is not corrected by a pacemaker.
have untreated, severe breathing problems during your sleep (sleep apnea).
take certain medicines called monoamine oxidase (MAO) inhibitors (e.g., selegiline, phenelzine, linezolid). 
Talk to your healthcare provider before starting treatment if you have any of these conditions or do not know if you have any of these conditions.
