Nuplazid (pimavanserin) is a prescription drug used to treat hallucinations and delusions related to Parkinson’s disease psychosis. Nuplazid can cause side effects that range from mild to serious. Examples include nausea and confusion.

Specifically, Nuplazid is prescribed to treat the following symptoms related to Parkinson’s disease psychosis in adults:

Nuplazid comes as an oral tablet and an oral capsule and contains the active ingredient pimavanserin. (An active ingredient is what makes a drug work.)

Keep reading to learn about the common, mild, and serious side effects Nuplazid can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during Nuplazid treatment. Examples of the drug’s commonly reported side effects include:

Mild side effects have been reported with Nuplazid. These include:

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Nuplazid unless your doctor recommends it.

Nuplazid may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* An allergic reaction is possible after taking Nuplazid, but this side effect wasn’t reported in studies.

Serious side effects have been reported with Nuplazid. These include:

If you develop serious side effects while taking Nuplazid, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after taking Nuplazid, but this side effect wasn’t reported in studies.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Nuplazid, visit MedWatch.

Get answers to some frequently asked questions about Nuplazid’s side effects.

Does Nuplazid make you sleepy?

Sleepiness wasn’t specifically reported as a side effect in Nuplazid studies, but fatigue was. While fatigue was an uncommon side effect, it led some participants to stop taking the drug.

Talk with your doctor if you feel unusually sleepy or fatigued while taking Nuplazid. They can recommend ways to help manage your symptoms.

If I stop taking Nuplazid abruptly, will I experience certain side effects?

It’s not likely. In studies, no specific side effects related to abruptly stopping Nuplazid were reported.

Keep in mind that hallucinations and delusions related to Parkinson’s disease psychosis may return or get worse after stopping Nuplazid. (Nuplazid is used to treat these symptoms.)

Do not stop taking Nuplazid without first talking with your doctor. If needed, they can suggest a different treatment option for your condition.

How long does it take for side effects of Nuplazid to go away?

In Nuplazid’s studies, researchers collected data over the course of 6 weeks on side effects of the drug. In these studies, most people didn’t stop Nuplazid due to side effects, which suggests most were temporary or manageable.

If you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Nuplazid unless your doctor recommends it. On average, it takes 11–12 days for this drug to be cleared from your system and 41–42 days for this drug’s active metabolite* to leave your body.

Talk with your doctor or pharmacist if you have questions about side effects during Nuplazid treatment.

* An active metabolite is a substance that is formed when your body breaks down a drug. The active metabolite of a drug may affect your body in the same ways that the drug does.

Learn more about some of the side effects Nuplazid may cause.

Increased risk of death in older adults with dementia-related psychosis

Nuplazid has a boxed warning for the risk of death in certain older adults. A boxed warning is the most serious warning from the FDA.

Nuplazid belongs to a group of drugs called antipsychotics. Certain older adults have an increased risk of death from taking these drugs. This risk applies to people ages 65 years and older with psychosis that’s related to dementia.

With psychosis, a person loses touch with reality. Symptoms of psychosis can include:

  • hallucinations
  • delusions
  • disorganized behavior (unpredictable behavior that doesn’t seem to fit the situation)
  • catatonia

Nuplazid is used to treat hallucinations and delusions related to Parkinson’s disease psychosis. This drug is not approved for use in people with dementia-related psychosis unless their hallucinations and delusions are related to Parkinson’s disease.

What might help

If you have hallucinations, delusions, or other symptoms of psychosis that are different, more frequent, or more severe during Nuplazid treatment, tell your doctor. If they think your symptoms are due to dementia and not related to psychosis from Parkinson’s, they may have you stop taking the drug.

Your doctor can tell you and your caregivers about the pros and cons of taking this drug for your condition.

Long QT syndrome

While rare, it was seen in studies that Nuplazid can cause a specific change in the heart’s electrical pattern. This change may lead to long QT syndrome, a heart rhythm problem that can result in a life threatening condition called torsades de pointes. However, there were no reports of torsades de pointes in the drug’s studies.

Symptoms of long QT syndrome may include:

  • fluttering sensation in your chest
  • dizziness
  • fainting

Factors that can increase the risk of long QT syndrome when taking Nuplazid include:

  • use of other medications that may cause long QT syndrome, such as:
  • congenital (inherited) long QT syndrome
  • heart rhythm problems in the past
  • slow heart rate
  • low levels of potassium or magnesium in your blood

What might help

If you have symptoms of long QT syndrome, tell your doctor so they can examine you and check your heart. If you have factors that increase the risk of this side effect, your doctor may not recommend Nuplazid for you. Or they may monitor you regularly with an electrocardiogram (EKG).

Allergic reaction

Like most drugs, Nuplazid can cause an allergic reaction in some people. This side effect wasn’t seen in studies but was reported after the drug was approved.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Nuplazid, they’ll decide whether you should continue taking it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Nuplazid, they may have you switch to a different treatment.

Keeping track of side effects

During your Nuplazid treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Nuplazid affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Nuplazid.

Boxed warning: Increased risk of death in older adults with dementia-related psychosis

Nuplazid has a boxed warning for the increased risk of death in older adults with dementia-related psychosis. A boxed warning is the most serious warning from the FDA.

Certain older adults have an increased risk of death with the use of antipsychotic drugs, such as Nuplazid. This risk applies to people ages 65 years and older with psychosis that’s related to dementia.

To learn more, see the “Side effects explained” section above.

Other warnings

Nuplazid can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Nuplazid is a good treatment option for you.

Talk with your doctor about your health history before starting Nuplazid. Be sure to tell them if any of the following factors apply to you:

Alcohol and Nuplazid

There are no known interactions between alcohol and Nuplazid. However, if you drink alcohol, your doctor may recommend limiting or avoiding it while taking Nuplazid. This is because heavy or long-term alcohol use could make movement-related symptoms of Parkinson’s disease worse.

Also, in rare cases, alcohol intoxication may cause psychosis, including hallucinations. (Nuplazid is used to treat hallucinations and delusions related to Parkinson’s disease psychosis.)

In addition, alcohol can worsen the side effects of Sinemet (levodopa/carbidopa), a medication commonly prescribed for Parkinson’s disease.

If you have questions about consuming alcohol during Nuplazid treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Nuplazid

There’s limited information about the safety of Nuplazid use during pregnancy or while breastfeeding.

Pregnancy

It’s not known whether it’s safe to take Nuplazid during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor before starting treatment with Nuplazid.

Breastfeeding

It isn’t known whether Nuplazid is safe to take while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor before starting this medication.

Like most drugs, Nuplazid can cause a number of side effects that range from mild to serious. But most are temporary and go away after a few days to weeks. If you have questions about side effects Nuplazid can cause, talk with your doctor. Examples to help get you started include:

  • Do I have a higher risk of side effects than other people taking Nuplazid?
  • Are Nuplazid’s side effects similar to those of other antipsychotic medications?
  • How will we monitor for possible side effects during Nuplazid treatment?

To learn more about Nuplazid, see these articles:

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.