What Drugs Cause Serotonin Syndrome?

Medically Reviewed by Johnelle Smith, M.D. on September 2, 2022

A variety of drugs and substances can affect a brain chemical known as serotonin. If your body has too much serotonin in its system, however, this can cause a potentially serious condition known as serotonin syndrome. This may require treatment, if severe.

Serotonin Syndrome

A number of common prescription medications can cause a serious condition known as “serotonin syndrome,” also known as serotonin toxicity.

Serotonin syndrome can cause mild to severe symptoms. The primary treatment is stopping use of the drug that is affecting your serotonin levels.

List Of Drugs That Can Cause Serotonin Syndrome

Serotonin syndrome is typically caused by taking one or more medications that affect the levels of serotonin — a neurotransmitter in the brain.

This can be caused by the use of certain antidepressant medications. Mixing pain medications, illicit drugs, or certain over-the-counter drugs with antidepressants can also lead to this.

Here is list of serotonergic drugs and supplements that could potentially cause serotonin syndrome:

1. Antidepressant Medications

Certain classes of medications prescribed for depression and anxiety disorders are known to affect your brain’s serotonin receptors.

This includes selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors (MAOIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, and more.

Antidepressants that can potentially cause serotonin syndrome include:

2. Pain Medications

Some prescription and over-the-counter medications for headaches, migraines, and other forms of mild to severe pain can potentially cause serotonin syndrome.

Pain medications that can affect serotonin levels include:

3. Supplements

Certain herbal and nutritional supplements can affect your serotonin levels and place you at risk for serotonin toxicity, if taken in very high doses or mixed with other serotonergic drugs.

This includes:

  • St. John’s Wort
  • ginseng
  • nutmeg
  • Syrian rue
  • tryptophan

Taking these supplements with other serotonergic agents (i.e. drugs that affect serotonin levels) can risk the development of mild to severe serotonin syndrome.

4. Illicit Drugs

Some illicit drugs can increase serotonin levels, and therefore carry a risk of developing serotonin syndrome, particularly in high doses.

Illicit drugs associated with serotonin syndrome include:

5. Other Drugs

A variety of miscellaneous drugs for treating cough, colds, or nausea, for example, can affect serotonin levels, as can certain antiviral drugs and antibiotics.

Other drugs associated with serotonin syndrome include:

  • Lithium (a mood stabilizer)
  • granisetron (Kytril)
  • ondansetron (Zofran)
  • droperidol (Inapsine)
  • dextromethorphan (Delsym)
  • linezolid (Zyvox)
  • ritonavir (Norvir)
  • droperidol
  • metoclopramide

What Are The Risk Factors For Serotonin Syndrome?

Serotonin syndrome is broadly caused by having too much serotonin in your system. Some people can be at greater risk of developing this than others.

You may be at greater risk of serotonin syndrome if you:

  • take multiple drugs that are known to affect serotonin levels (e.g. antidepressants and opioids)
  • take herbal or dietary supplements known to increase serotonin levels
  • use illicit drugs that can affect serotonin levels
  • recently started/increased your dose of a drug known to affect serotonin levels
  • misuse one or more drugs that affect serotonin

Signs And Symptoms Of Serotonin Syndrome

Serotonin syndrome can become life-threatening if left untreated.

If you or a loved one is taking drugs/supplements known to affect serotonin, here are the signs and side effects of this condition to look out for.

Mild to moderate symptoms of serotonin include:

  • agitation
  • confusion
  • insomnia
  • muscle rigidity
  • twitching muscles
  • diarrhea
  • dilated pupils
  • shivering
  • goosebumps
  • tremor
  • abnormal eye movements (side to side)

Severe serotonin syndrome symptoms can include:

  • tremors
  • rapid heart rate
  • high blood pressure
  • high body temperature
  • irregular heartbeat
  • delirium
  • seizures
  • passing out

If you or a loved one is experiencing symptoms of serotonin syndrome, call your healthcare provider or visit an emergency room right away.

Without treatment, a severe case of serotonin syndrome can lead to unconsciousness and death.

What Is The Treatment For Serotonin Syndrome?

According to the Cleveland Clinic, a treatment plan for serotonin syndrome will largely depend on the severity of the symptoms you are experiencing.

For mild symptoms, treatment may include:

  • discontinuing/tapering off of the medication that is affecting your serotonin levels (Note: consult a doctor before altering your dose)
  • taking a serotonin blocker (e.g. cyproheptadine)

For moderate symptoms:

  • hospitalization/medical observation
  • intravenous (IV) fluids
  • treatment for mild symptoms

For severe symptoms:

  • close observation within an intensive care unit
  • medicine to control heart rate/blood pressure
  • a sedative for severe agitation or anxiety (e.g. benzodiazepines)
  • a breathing tube for mechanical ventilation
  • giving oxygen

If your condition has developed as a result of substance abuse, additional treatment within an addiction treatment program may be recommended.

What Is Treatment For Prescription Drug Addiction?

Serotonin syndrome is just one of many possible consequences that can occur from misusing drugs that interact with the body’s serotonin receptors.

Overcoming prescription drug abuse or addiction, and therefore preventing serotonin syndrome, may require additional behavioral health treatment.

Treatment for prescription drug abuse might involve:

Find Help For Drug Abuse Today

Millions of Americans struggle with some form of substance abuse. If this describes you or someone you know, you’re not alone. And we may be able to help.

Call our helpline today to learn more about prescription drug abuse, or to find a treatment program that’s right for you.

This page does not provide medical advice. See more

Addiction Resource aims to provide only the most current, accurate information in regards to addiction and addiction treatment, which means we only reference the most credible sources available.

These include peer-reviewed journals, government entities and academic institutions, and leaders in addiction healthcare and advocacy. Learn more about how we safeguard our content by viewing our editorial policy.

  • Was this Helpful?
  • YesNo
Medically Reviewed by
Johnelle Smith, M.D. on September 2, 2022
Let us walk you through the treatment process. We're here to help.
For 24/7 Treatment Help:
100% Free & Confidential. Call (844) 616-3400