What the label lists and what reports show
Pimavanserin side effects
Pimavanserin's FDA label: “Most common adverse reactions (≥5% and twice the rate of placebo): peripheral edema and confusional state.” FAERS holds 55,140 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is confusional state (4,296 reports).
- Generic approved
- Boxed warning
Check it at the source: the pimavanserin FDA label on DailyMed (effective June 18, 2026, Acadia Pharmaceuticals Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsMost common adverse reactions (≥5% and twice the rate of placebo): peripheral edema and confusional state.
Table 1 Adverse Reactions in Placebo-Controlled Studies of 6-Week Treatment Duration and Reported in ≥2% and >Placebo
| Reaction | NUPLAZID 34 mg N=202 | Placebo N=231 |
|---|---|---|
| Nausea | 7% | 4% |
| Constipation | 4% | 3% |
| Peripheral edema | 7% | 2% |
| Gait disturbance | 2% | <1% |
| Hallucination | 5% | 3% |
| Confusional state | 6% | 3% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following serious adverse reactions are discussed elsewhere in the labeling: Increased Mortality in Elderly Patients with Dementia-Related Psychosis [see Boxed Warning and Warnings and Precautions (5.1) ] QT Interval Prolongation [see Warnings and Precautions (5.2) ] Most common adverse reactions (≥5% and twice the rate of placebo): peripheral edema and confusional state. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Acadia Pharmaceuticals Inc. at 1-844-422-2342 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The clinical trial database for NUPLAZID consists of over 1200 subjects and patients exposed to one or more doses of NUPLAZID. Of these, 616 were patients with hallucinations and delusions associated with Parkinson's disease psychosis (PDP). In the placebo-controlled setting, the majority of experience in patients comes from studies evaluating once-daily NUPLAZID doses of 34 mg (N=202) compared to placebo (N=231) for up to 6 weeks. …
Source: FDA drug label, Acadia Pharmaceuticals Inc., effective June 18, 2026 (SPL set 1e6bea44-57d6-4bac-9328-46e1ee59f83b), via openFDA; the full label on DailyMed
What do FAERS reports show?
55,140 reports list pimavanserin among the medicines taken, each a report of something that happened, not proof the medicine caused it; 14,158 are coded as a death and 9,077 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 17 reactions below, 8 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Pimavanserin: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions