Pimavanserin

Pronunciation: pim-ah-VAN-seh-rin.

Generic name
pimavanserin
Drug class
Atypical antipsychotic (selective serotonin 5-HT2A receptor inverse agonist/antagonist)
Form
Capsule (34 mg); tablet (10 mg)
Route
Oral
Legal status
Prescription-only

Availability and supply rules vary by country

Trade names by country: United States

Australia: · Full directory

What pimavanserin is and how it works

Pimavanserin is a prescription-only oral medicine specifically approved to treat hallucinations and delusions (seeing or believing things that are not real) that occur as part of Parkinson's disease psychosis. It is not a general treatment for psychosis caused by dementia. (1)

You take pimavanserin once a day, with or without food, at a fixed dose without needing to gradually increase it. Because antipsychotic medicines as a class carry a real risk of increased death in older adults with dementia-related psychosis, your prescriber will confirm that your hallucinations and delusions are specifically related to Parkinson's disease before prescribing it, and will discuss this risk with you.

Mechanism of action: how pimavanserin works

Pimavanserin is a selective serotonin 5-HT2A receptor inverse agonist/antagonist, with lower affinity for 5-HT2C receptors, and no appreciable affinity for dopamine (including D2), histaminergic, muscarinic, or adrenergic receptors. This mechanism is thought to underlie its antipsychotic effect in Parkinson's disease psychosis without worsening motor symptoms, unlike dopamine-blocking antipsychotics. (1)

What pimavanserin is used for

Parkinson's disease psychosis

Approved specifically for the treatment of hallucinations and delusions associated with Parkinson's disease psychosis in adults. This is a narrow, specific indication. (1)

Before taking pimavanserin

Do not take / not appropriate for

  • Do not take pimavanserin if you have had an allergic reaction to it or to any of its ingredients. (all confirmed markets) (1)
  • Pimavanserin is not approved for treating psychosis caused by dementia in general (only Parkinson's disease psychosis specifically) -- do not use it for other types of dementia-related psychosis unless your prescriber has specifically determined your hallucinations/delusions relate to Parkinson's disease. (United States) (1)

Tell your clinician about

  • Whether you or a family member has ever had an irregular heartbeat or a condition called 'QT prolongation', or take other medicines that affect heart rhythm.
  • All other medicines you take, especially anything that strongly affects the CYP3A4 liver enzyme (such as certain antifungal or antibiotic medicines).
  • Any history of falls.
  • Whether you have severe kidney impairment.
  • Pregnancy, plans for pregnancy, or breastfeeding.
  • Whether the psychosis being treated is definitely related to Parkinson's disease, as opposed to another form of dementia -- this affects whether pimavanserin is an appropriate choice at all.
(1)

How to take pimavanserin

  • Take pimavanserin by mouth once a day, with or without food, at the same time each day.
  • The usual dose is fixed at 34 mg once daily -- it does not need to be gradually increased (titrated).
  • If you have difficulty swallowing capsules, they can be opened and the contents sprinkled over a small amount of soft food (such as applesauce, yoghurt, or pudding) or into a liquid nutritional supplement, and taken right away.
  • Do not change your dose on your own -- your prescriber may adjust it if you are also taking certain other medicines.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2)

Missed dose

If you miss a dose, take it as soon as you remember unless it is almost time for your next dose -- in that case, skip the missed dose and continue your regular schedule. Do not take two doses at once. Contact your prescriber if you are unsure.

Overdose

Seek urgent medical attention if too much pimavanserin may have been taken, or if you develop an irregular heartbeat, severe drowsiness, or fainting. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Swelling of the legs, ankles, or feet (peripheral oedema) -- occurred in about 7% of people, compared with 2% on placebo.

What to notice: Swelling of the legs, ankles, or feet (peripheral oedema) -- occurred in about 7% of people, compared with 2% on placebo.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Confused state -- occurred in about 6% of people, compared with 3% on placebo.

What to notice: Confused state -- occurred in about 6% of people, compared with 3% on placebo.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Nausea -- about 7%.

What to notice: Nausea -- about 7%.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Hallucination -- about 5% (can occur even while being treated for hallucinations, and should be discussed with your prescriber).

What to notice: Hallucination -- about 5% (can occur even while being treated for hallucinations, and should be discussed with your prescriber).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Constipation -- about 4%.

What to notice: Constipation -- about 4%.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Increased risk of death in elderly patients with dementia-related psychosis — boxed_warning

Symptoms: This is a population-level risk identified in clinical trials of antipsychotic medicines as a class, not a specific symptom to watch for.

Action: This is exactly why pimavanserin is only approved for Parkinson's disease psychosis, not dementia-related psychosis generally. Discuss the overall risks and benefits with your prescriber, particularly if you are an older adult. (1)

Signs of an irregular heartbeat (QT prolongation) — high caution

Symptoms: Fainting, palpitations, or dizziness.

Action: Contact your prescriber promptly. Pimavanserin can prolong the QT interval; avoid combining it with other medicines that do the same, and tell your prescriber about any personal or family history of heart rhythm problems. (1)

Falls — moderate caution

Symptoms: Dizziness, unsteadiness, or a fall.

Action: Tell your prescriber if you feel unsteady or have a fall while taking pimavanserin, particularly if you also have Parkinson's disease, which independently raises fall risk. (1)

Worsening hallucinations, confusion, or new psychiatric symptoms — moderate caution

Symptoms: New or worsening hallucinations, confusion, or behavioural changes.

Action: Contact your prescriber -- this may need reassessment of your treatment. (1)

Interactions

  • Strong CYP3A4 inhibitor medicines (such as certain antifungal or antibiotic medicines) can raise pimavanserin levels -- your prescriber will typically reduce your dose to 10 mg once daily if you need one of these. (1)
  • Strong or moderate CYP3A4 inducer medicines can lower pimavanserin levels and reduce its effectiveness -- these combinations are generally avoided. (1)
  • Other medicines that prolong the QT interval should be used with caution alongside pimavanserin. (1)
  • No dose adjustment is needed with carbidopa/levodopa. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

There is no human data on pimavanserin use in pregnancy. Animal studies did not show birth defects at doses 10-12 times the maximum recommended human dose, though the mother animals showed toxicity at twice that dose. Discuss with your prescriber if you are pregnant or planning pregnancy. (1) (2)

Breastfeeding

There is no information on whether pimavanserin passes into human breast milk. Discuss the balance of benefits and risks with your prescriber before breastfeeding. (1) (2)

Children

Safety and effectiveness in children have not been established. A trial studying pimavanserin for irritability associated with autism spectrum disorder in children and adolescents aged 5-17 did not show it was effective for that use. (1) (2)

Elderly

This medicine's boxed warning specifically concerns elderly patients with dementia-related psychosis -- it is only approved for Parkinson's disease psychosis, and its use in older adults should always involve a careful discussion of risks and benefits with the prescriber. (1) (2)

Hepatic_impairment

No dose adjustment is recommended based on the hepatic impairment study reviewed for this medicine. (1) (2)

Renal_impairment

No dose adjustment is needed for mild-to-severe kidney impairment, but caution is advised in severe impairment (creatinine clearance under 30 mL/min) because drug exposure increases. (1) (2)

Source_ids

US-DAILYMED-NUPLAZID-2026 (1) (2)

Monitoring

Before starting

  • Confirmation that hallucinations/delusions are specifically related to Parkinson's disease psychosis, not another form of dementia
  • Review of heart rhythm history and other QT-prolonging medicines
  • Review of all other medicines for CYP3A4 interactions
  • Assessment of fall risk

During treatment

  • Monitoring for new or worsening confusion or hallucinations.
  • Monitoring for signs of an irregular heartbeat.
  • Monitoring for falls, swelling, or nausea.
  • Periodic reassessment of whether continued treatment remains appropriate.
(1)

Storage

Store at room temperature, away from moisture and light, out of reach of children.

Study the drug class: Atypical antipsychotics

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information; verify against the current full label before prescribing. Regulatory status in the UK, EU, Canada, Australia, and New Zealand could not be verified live in this session -- do not assume availability outside the United States.

United States

Indication: Hallucinations and delusions associated with Parkinson's disease psychosis (NOT dementia-related psychosis generally)

Dose summary: 34 mg once daily without titration; reduce to 10 mg once daily with strong CYP3A4 inhibitors; avoid strong/moderate CYP3A4 inducers; no adjustment needed with carbidopa/levodopa.

Renal context: No adjustment for mild-to-severe impairment; caution advised in severe impairment (CrCl <30 mL/min) due to increased exposure. (1)

Mechanism of action

Hepatic guidance

No dose adjustment recommended based on the hepatic impairment study reviewed.

Overdose note

Manage supportively; monitor cardiac rhythm given the QT-prolongation risk. (1)

Frequently asked questions

Is pimavanserin (Nuplazid) available outside the United States?

This could not be confirmed. Pimavanserin is FDA-approved and available in the United States. Live searches of UK, EU, Canadian, Australian, and New Zealand regulator sources during this research did not find confirmation of authorisation in any of those markets -- this is recorded as unable to verify, not as a confirmed 'no', so check directly with a local pharmacist or regulator if you are outside the US. (1)

Is pimavanserin approved for all types of dementia-related psychosis?

No. This is an important distinction. Pimavanserin's boxed warning covers the general antipsychotic-class risk of increased mortality in elderly patients with dementia-related psychosis, but the medicine itself is only APPROVED for hallucinations and delusions specifically related to Parkinson's disease psychosis. The FDA label explicitly states it is not approved for dementia-related psychosis in general. (1)

Why does pimavanserin carry a boxed warning if it isn't used for dementia generally?

The boxed warning reflects a risk seen across antipsychotic medicines as a class in elderly patients with dementia-related psychosis, based on clinical trial data. Parkinson's disease psychosis, the condition pimavanserin is actually approved to treat, occurs in a related but distinct patient population, and prescribers must weigh this class-wide risk when considering pimavanserin, even though it is not itself approved for dementia-related psychosis broadly. (1)

What is the mechanism of action of pimavanserin?

Pimavanserin is a selective serotonin 5-HT2A receptor inverse agonist/antagonist, with lower affinity for 5-HT2C receptors, and no appreciable affinity for dopamine (including D2), histaminergic, muscarinic, or adrenergic receptors. This mechanism is thought to underlie its antipsychotic effect in Parkinson's disease psychosis without worsening motor symptoms, unlike dopamine-blocking antipsychotics. (1)

What is the generic name of Pimavanserin?

The generic name is pimavanserin. (1)

What class of drug is pimavanserin?

Pimavanserin is classed as: Atypical antipsychotic (selective serotonin 5-HT2A receptor inverse agonist/antagonist). (1)

References

  1. NUPLAZID (pimavanserin) capsules and tablets, for oral use -- full prescribing information (setid 1e6bea44-57d6-4bac-9328-46e1ee59f83b, updated 18 June 2026)U.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, ACADIA Pharmaceuticals Inc. · United States · accessed 2026-07-30 · source 1
  2. P/0351/2016: EMA decision of 2 December 2016 on a paediatric investigation plan for pimavanserin (EMEA-001688-PIP03-16)European Medicines Agency (EMA) -- Paediatric Committee decision · European Union · accessed 2026-07-30 · source 2
  3. NUPLAZID (PIMAVANSERIN TARTRATE) CAPSULE NUPLAZID (PIMAVANSERIN TARTRATE) TABLET, COATED [ACADIA PHARMACEUTICALS INC.] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
  4. Pimavanserin — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
  5. NUPLAZID — FDA approval record (Drugs@FDA NDA207318)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
  6. pimavanserin — RxNorm normalized drug concept (RXCUI 1791685)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6

Brand names by country

Single-ingredient pimavanserin names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • NUPLAZID10 mg, 34 mg · acadia pharmaceuticals inc.
View brands in additional countries.

This page provides general reference information about pimavanserin (Nuplazid) and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions should be made with your prescriber. Availability outside the United States could not be confirmed at the time this page was drafted.

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