No single test can confirm a serotonin syndrome diagnosis. Your doctor will diagnose the condition by ruling out other possibilities.

Your doctor will likely begin by asking about your symptoms, medical history and any medications you're taking. Your doctor will also conduct a physical examination.

To make sure your symptoms are caused by serotonin syndrome and not due to another cause, your doctor may use tests to:

  • Measure levels of any drugs you're using
  • Check for signs of infection
  • Check body functions that may be affected by serotonin syndrome

A number of conditions can cause symptoms similar to those of serotonin syndrome. Minor symptoms can be caused by several conditions. Moderate and severe symptoms similar to those of serotonin syndrome could be caused by:

  • A serious reaction to certain medications, such as some anesthetics, antipsychotic drugs and other agents known to produce these severe reactions
  • An overdose of illicit drugs, antidepressant medications or other medications that increase serotonin levels
  • Damage associated with illicit drug use
  • Severe alcohol withdrawal

Your doctor may order additional tests to rule out other causes of your symptoms. Tests may include:

  • Blood and urine tests
  • Chest X-ray
  • computed tomography (CT) scan
  • Spinal tap (lumbar puncture)


Treatment of serotonin syndrome depends on the severity of your symptoms.

  • If your symptoms are minor, a visit to the doctor and stopping the medication causing the problem may be enough.
  • If you have symptoms that concern your doctor, you may need to go to the hospital. Your doctor may have you stay in the hospital for several hours to make sure your symptoms are improving.
  • If you have severe serotonin syndrome, you'll need intensive treatment in a hospital.

Depending on your symptoms, you may receive the following treatments:

  • Muscle relaxants. Benzodiazepines, such as diazepam (Valium, Diastat) or lorazepam (Ativan), can help control agitation, seizures and muscle stiffness.
  • Serotonin-production blocking agents. If other treatments aren't working, medications such as cyproheptadine can help by blocking serotonin production.
  • Oxygen and intravenous (IV) fluids. Breathing oxygen through a mask helps maintain oxygen levels in your blood, and IV fluids are used to treat dehydration and fever.
  • Drugs that control heart rate and blood pressure. These may include esmolol (Brevibloc) or nitroprusside (Nitropress) to reduce a high heart rate or high blood pressure.

    If your blood pressure is too low, your doctor may give you phenylephrine (Vazculep) or epinephrine (Adrenalin, Epipen, others).

  • A breathing tube and machine and medication to paralyze your muscles. You may need this treatment if you have a high fever.

Milder forms of serotonin syndrome usually go away within 24 to 72 hours of stopping medications that increase serotonin. You may need to take medications to block the effects of serotonin already in your system.

However, symptoms of serotonin syndrome caused by some antidepressants could take several weeks to go away completely. These medications remain in your system longer than do other medications that can cause serotonin syndrome.

Preparing for your appointment

Because serotonin syndrome can be a life-threatening condition, seek emergency treatment if you have worsening or severe symptoms.

If your symptoms aren't severe, you're likely to start by seeing your family doctor or a general practitioner. Here's some information to help you get ready for your appointment and to know what to expect from your doctor.

What you can do

  • Be aware of any pre-appointment steps you need to take. When you make the appointment, be sure to ask if there's anything you need to do in advance, such as quitting any of the current medications or supplements you take.
  • Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Write down key personal information, including any major stresses or recent life changes.
  • Make a list of all medications, vitamins or supplements that you're taking.
  • Take a family member or friend along, if possible. Sometimes it can be difficult to absorb all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
  • Write down questions to ask your doctor.

Preparing a list of questions will help you make the most of your time with your doctor. For symptoms you think may be caused by serotonin syndrome, some basic questions to ask your doctor include:

  • Is serotonin syndrome most likely causing my symptoms, or could it be something else?
  • Other than the most likely cause, what are other possible causes of my symptoms?
  • What kinds of tests do I need?
  • What is the best course of action?
  • What are the alternatives to the primary approach that you're suggesting?
  • I have other health conditions. How can I best manage them together?
  • Can I still take the medications I've been prescribed, or will I need to change them or change the dose?
  • Are there any restrictions that I need to follow, such as avoiding certain drugs or supplements?

Don't hesitate to ask any other questions you have.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, such as:

  • When did you begin experiencing symptoms?
  • Have your symptoms been continuous or occasional?
  • How severe are your symptoms?
  • What prescription and over-the-counter medications do you take?
  • Do you use any illicit drugs?
  • Do you take any dietary supplements?

Jan 22, 2022

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