What the label lists and what reports show
Quetiapine side effects
Quetiapine's FDA label: “Most common adverse reactions (incidence ≥5% and twice placebo): Adults: somnolence, dry mouth, dizziness, constipation, asthenia, abdominal pain, postural hypotension, pharyngitis, weight gain, lethargy, ALT increased, dyspepsia ( 6.1 ) Children and …” FAERS holds 191,480 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 toxicity to various agents (10,154 reports).
- Generic listed
- Boxed warning
Check it at the source: the quetiapine FDA label on DailyMed (effective April 10, 2026, H2-Pharma, LLC); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are possible side effects of SEROQUEL?SEROQUEL can cause serious side effects, including: • See “What is the most important information I should know about SEROQUEL?” • stroke that can lead to death can happen in elderly people with dementia who take medicines like SEROQUEL • neuroleptic malignant syndrome (NMS). NMS is a rare but very serious condition that can happen in people who take antipsychotic medicines, including SEROQUEL. NMS can cause death and must be treated in a hospital. Call your healthcare provider right away if you become severely ill and have some or all of these symptoms:∘high fever∘excessive sweating∘rigid muscles∘confusion∘changes in your breathing, heartbeat, and blood pressure• falls can happen in some people who take SEROQUEL. These falls may cause serious injuries.• high blood sugar (hyperglycemia). High blood sugar can happen if you have diabetes already or if you have never had diabetes. […]
Source: FDA drug label, NDA020639 (Cheplapharm), as published by H2-Pharma, LLC, effective April 10, 2026 (SPL set 8ae62aaf-f8c5-417f-baac-0098369ca322), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence ≥5% and twice placebo): Adults: somnolence, dry mouth, dizziness, constipation, asthenia, abdominal pain, postural hypotension, pharyngitis, weight gain, lethargy, ALT increased, dyspepsia ( 6.1 ) Children and Adolescents: somnolence, dizziness, fatigue, increased appetite, nausea, vomiting, dry mouth, tachycardia, weight increased ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact H2-Pharma at 1-888-864-2308 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Table 10: Adverse Reaction Incidence in 3-Week Placebo-Controlled Clinical Trials for the Treatment of Bipolar Mania (Adjunct Therapy)
| Preferred Term | SEROQUEL (n=196) | PLACEBO (n=203) |
|---|---|---|
| Somnolence | 34% | 9% |
| Dry Mouth | 19% | 3% |
| Headache | 17% | 13% |
| Asthenia | 10% | 4% |
| Constipation | 10% | 5% |
| Dizziness | 9% | 6% |
| Tremor | 8% | 7% |
| Abdominal Pain | 7% | 3% |
| Postural Hypotension | 7% | 2% |
| Agitation | 6% | 4% |
| Weight Gain | 6% | 3% |
| Pharyngitis | 6% | 3% |
| Back Pain | 5% | 3% |
| Hypertonia | 4% | 3% |
| Rhinitis | 4% | 2% |
| Peripheral Edema | 4% | 2% |
| Twitching | 4% | 1% |
| Dyspepsia | 4% | 3% |
| Depression | 3% | 2% |
| Amblyopia | 3% | 2% |
| Speech Disorder | 3% | 1% |
| Hypotension | 3% | 1% |
| Hormone Level Altered | 3% | 0% |
| Heaviness | 2% | 1% |
| Infection | 2% | 1% |
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 adverse reactions are discussed in more detail in other sections of the labeling: • Increased mortality in elderly patients with dementia-related psychosis [see Warnings and Precautions (5.1) ] • Suicidal thoughts and behaviors in adolescents and young adults [see Warnings and Precautions (5.2) ] • Cerebrovascular adverse reactions, including stroke in elderly patients with dementia-related psychosis [see Warnings and Precautions (5.3 )] • Neuroleptic Malignant Syndrome (NMS) [see Warnings and Precautions (5.4 )] • Metabolic changes (hyperglycemia, dyslipidemia, weight gain) [see Warnings and Precautions (5.5) ] • Tardive dyskinesia [see Warnings and Precautions (5.6 )] • Hypotension [see Warnings and Precautions (5.7 )] • Falls [see Warnings and Precautions (5.8 )] • Increases in blood pressure (children and adolescents) [see Warnings and Precautions (5.9 )] • Leukopenia, neutropenia and agranulocytosis [see Warnings and Precautions (5.10 )] • Cataracts [see Warnings and Precautions (5.11 )] • QT Prolongation [see Warnings and Precautions (5.12 )] • Seizures [see Warnings and Precautions (5.13 )] • Hypothyroidism [see Warnings and Precautions (5.14 )] • Hyperprolactinemia [see Warnings and Precautions (5.15 )] • Potential for cognitive and motor impairment [see Warnings and Precautions (5.16 )] • Body temperature regulation [see Warnings and Precautions (5.17 )] …
Source: FDA drug label, NDA020639 (Cheplapharm), as published by H2-Pharma, LLC, effective April 10, 2026 (SPL set 8ae62aaf-f8c5-417f-baac-0098369ca322), via openFDA; the full label on DailyMed
What do FAERS reports show?
191,480 reports list quetiapine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 28,195 are coded as a death and 70,149 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, 10 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?
- Quetiapine: 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