The most commonly reported side effects of pimavanserin include hallucination, death, and product dose omission issue, based on 49,887 FDA adverse event reports from 2004 to 2025. 11.7% of reports found the drug to be ineffective.
Percentages show how often each reaction appears relative to total reports for pimavanserin.
1
Hallucination23.1%11,542
2
Death19.9%9,938
3
Drug Ineffective11.7%5,835
4
Product Dose Omission Issue8.1%4,021
5
Confusional State8.0%3,968
6
Fall7.3%3,656
7
Delusion5.1%2,550
8
Condition Aggravated4.2%2,102
9
Parkinson^s Disease4.2%2,102
10
Hallucination, Visual4.2%2,083
11
Gait Disturbance4.1%2,032
12
Urinary Tract Infection3.3%1,635
13
Somnolence3.3%1,627
14
Peripheral Swelling3.1%1,547
15
Adverse Drug Reaction3.0%1,513
These are voluntary reports and do not establish that pimavanserin caused these reactions.
Report severity
49.7%Serious24,808 reports
16.4%Hospitalizations8,188 reports
26.3%Fatal13,112 reports
Seriousness is determined by the reporter, not by OpenClaim.
Pimavanserin drug interactions
Other drugs that appear in adverse event reports alongside pimavanserin. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.
Also suspected
1
Levodopa2.1%1,068
2
Carbidopa1.9%964
3
Quetiapine-fumarate0.9%440
4
Istradefylline0.5%254
5
Droxidopa0.4%197
6
Amantadine0.4%183
7
Apomorphine-hydrochloride0.2%114
8
Donepezil-hydrochloride0.1%73
9
Rivastigmine0.1%70
10
Clozapine0.1%55
11
Pramipexole-dihydrochloride<0.1%48
12
Foscarbidopa<0.1%48
13
Foslevodopa<0.1%48
14
Clonazepam<0.1%45
15
Olanzapine<0.1%44
Taken alongside
1
Carbidopa22.6%11,270
2
Levodopa19.8%9,900
3
Quetiapine-fumarate9.1%4,549
4
Aspirin7.6%3,800
5
Ergocalciferol6.9%3,436
6
Atorvastatin-calcium6.6%3,315
7
Donepezil-hydrochloride6.6%3,315
8
Levothyroxine-sodium5.0%2,497
9
Acetaminophen4.7%2,320
10
Memantine-hydrochloride4.6%2,280
11
Clonazepam4.4%2,205
12
Tamsulosin-hydrochloride4.4%2,192
13
Metoprolol4.4%2,176
14
Omeprazole4.3%2,167
15
Rivastigmine4.3%2,155
Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.
Who reports pimavanserin side effects
38.1% of pimavanserin adverse event reports involve female patients and 60.1% involve male patients. The largest age group is elderly at 93%. These figures reflect who reports side effects, not underlying risk.
Sex
Female38.1%
Male60.1%
Unknown1.8%
Age group
< 2<0.1%
2–11<0.1%
12–17<0.1%
18–647.3%
65+92.7%
What is pimavanserin used for
Conditions and purposes for which patients were taking pimavanserin when the adverse event was reported.
