Learning About Neuroleptic Malignant Syndrome (NMS)

What is NMS?

Neuroleptic malignant syndrome (NMS) is a rare condition. It happens when a person has a reaction to antipsychotic medicine. These medicines are used to treat mental health conditions such as bipolar disorder or schizophrenia. There are also a few medicines used for nausea that can cause NMS.

Signs of NMS may include fever, changes in your heartbeat, and faster breathing. It may also include mental changes, such as having odd thoughts.

NMS can cause serious problems. These may include kidney failure, liver failure, damage to the muscles, or blood clots.

The first step in treatment for NMS is stopping the medicine that caused it. Then the problems created by NMS can be treated.

What causes NMS?

Most people can take antipsychotic medicines with no problems. But in rare cases, those medicines can cause a dangerous reaction. The reaction most often happens soon after you start to take a new medicine. But it can also happen after you have taken the medicine for a long time. It can even happen after you stop taking the medicine.

Examples of antipsychotic medicines include:

• Aripiprazole (Abilify).
• Chlorpromazine.
• Haloperidol (Haldol).
• Risperidone (Risperdal).
• Olanzapine (Zyprexa).

Sometimes NMS is caused by certain nausea medicines. Examples include:

• Metoclopramide.
• Promethazine.

What are the symptoms?

Symptoms of NMS may include:

• Odd thoughts and other mental changes.
• Fever.
• Sweating a lot.
• A fast heartbeat.
• Changes in breathing patterns.
• Rigid muscles.

How is NMS treated?

NMS can cause serious health problems, so you'll be treated in the hospital. You may need to spend time in the intensive care unit (ICU).

Your doctor will have you stop taking the medicine that caused the reaction. Then your care team will treat the problems caused by NMS. You may get fluids through an I.V. You may get medicine or other treatment to lower your fever. Your breathing, heart rate, and blood pressure will be tracked. They'll take blood for tests to check for organ damage and other problems.

If you had a severe reaction, you may be in the hospital for several days or weeks. Mild symptoms may go away sooner.

You probably will be able to take another antipsychotic medicine after you recover from NMS. But some people have NMS more than once. That means it will be important in the future to get treatment before your symptoms become severe.