Understanding Serotonin Syndrome

Serotonin is a type of hormone in your body. It helps send signals in your brain and nervous system. Medicines that treat depression and anxiety can raise the amount of serotonin in your body. Some supplements can increase your serotonin. And some illegal drugs can do this, too. If you have too much serotonin in your body, it can lead to dangerous side effects. This is known as serotonin syndrome. Tell your providers about all medicines you take. This can help prevent serotonin syndrome.

What causes serotonin syndrome?

Serotonin syndrome can happen:

• If you increase the dose of a medicine you are taking

• When you start a new medicine

• When certain medicines are combined

• If you take supplements, medicines, or drugs that affect serotonin

Symptoms of serotonin syndrome

Symptoms can range from mild to life-threatening and can include:

• Anxiety

• Restlessness

• Confusion

• Large pupils

• Headache

• Nausea

• Vomiting

• Diarrhea

• Fast heart rate

• Fast breathing

• Stiff or twitching muscles

• Shivering or shaking

• A lot of sweating

Diagnosing serotonin syndrome

There is no test for serotonin syndrome. Your provider will give you a physical exam. They will ask questions about the medicines you take. Tell them:

• All the prescription and over-the-counter medicines you take

• Any vitamins, herbs, or other supplements you take

• If you take illegal drugs and what drugs you have used

Treatment for serotonin syndrome

Treatment will depend on how severe your symptoms are. For mild symptoms, you may just need to stop taking certain medicines. For more severe symptoms, you may need extra oxygen or IV (intravenous) fluids. You may need to stay one or more nights in the hospital. You may be given medicine to lower the amount of serotonin your body makes.

Possible complications of serotonin syndrome

If untreated, serotonin syndrome can lead to:

• Seizures

• Kidney failure

• Death

Call 911

Someone should call 911 if you have any of these:

• Passing out (loss of consciousness), fainting, or are unresponsive

• Seizures

• Confusion, extreme drowsiness, or trouble awakening

• Rapid, irregular heartbeat or pulse

• Trouble breathing or shortness of breath

• Chest pain

When to call your healthcare provider

Call your healthcare provider if you have any of these:

• Fever of 100.4°F (38°C) or higher, or as directed by your provider

• Symptoms that don’t get better, or get worse

• New symptoms