OpenClaim

Olanzapine Side Effects

The most commonly reported side effects of olanzapine include off label use, weight increased, and diabetes mellitus, based on 108,958 FDA adverse event reports from 2004 to 2025. 6.1% of reports found the drug to be ineffective.

#1 Reported: Off Label UseAll side effects ↓Top Co-Medication: Quetiapine-fumarateDrug interactions ↓74% of Reports Are AdultDemographics ↓

Olanzapine side effects

Percentages show how often each reaction appears relative to total reports for olanzapine.

1
Drug Ineffective6.1%6,694
2
Off Label Use5.1%5,571
3
Weight Increased4.1%4,497
4
Diabetes Mellitus3.9%4,273
5
Toxicity To Various Agents3.7%4,011
6
Drug Interaction3.1%3,409
7
Nausea3.1%3,373
8
Somnolence3.1%3,351
9
Fatigue2.8%3,020
10
Anxiety2.6%2,810
11
Vomiting2.4%2,652
12
Suicide Attempt2.4%2,596
13
Weight Increased2.3%2,515
14
Condition Aggravated2.3%2,482
15
Confusional State2.2%2,429

These are voluntary reports and do not establish that olanzapine caused these reactions.

Report severity

85.4%Serious93,029 reports
43.4%Hospitalizations47,329 reports
12.2%Fatal13,267 reports

Seriousness is determined by the reporter, not by OpenClaim.

Olanzapine drug interactions

Other drugs that appear in adverse event reports alongside olanzapine. 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
Quetiapine-fumarate9.7%10,605
2
Risperidone7.4%8,105
3
Aripiprazole7.0%7,673
4
Clozapine6.5%7,102
5
Haloperidol4.1%4,450
6
Lorazepam3.2%3,461
7
Fluoxetine-hydrochloride3.0%3,274
8
Sertraline-hydrochloride2.9%3,209
9
Venlafaxine2.7%2,931
10
Diazepam2.6%2,801
11
Lithium2.4%2,650
12
Mirtazapine2.4%2,569
13
Paliperidone2.3%2,537
14
Lamotrigine2.2%2,427
15
Clonazepam2.0%2,139

Taken alongside

1
Lorazepam7.2%7,793
2
Acetaminophen6.5%7,029
3
Clonazepam4.6%4,978
4
Risperidone4.5%4,904
5
Ondansetron4.4%4,794
6
Levothyroxine-sodium4.2%4,589
7
Sertraline-hydrochloride4.0%4,344
8
Aspirin4.0%4,334
9
Omeprazole3.9%4,282
10
Quetiapine-fumarate3.9%4,208
11
Gabapentin3.6%3,970
12
Pantoprazole-sodium3.6%3,918
13
Lithium3.6%3,890
14
Atorvastatin-calcium3.4%3,656
15
Divalproex-sodium3.3%3,586

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 olanzapine side effects

44.9% of olanzapine adverse event reports involve female patients and 45.7% involve male patients. The largest age group is adult at 74%. These figures reflect who reports side effects, not underlying risk.

Sex

Female44.9%
Male45.7%
Unknown9.4%

Age group

< 21.1%
2–111.3%
12–174.3%
18–6473.6%
65+19.8%

What is olanzapine used for

Conditions and purposes for which patients were taking olanzapine when the adverse event was reported.

22q11.2 Deletion SyndromeAbdominal DiscomfortAbdominal Pain UpperAbnormal BehaviourAbnormal DreamsAccidental ExposureAccidental Exposure To ProductAccidental Exposure To Product By ChildAcute PsychosisAcute Stress DisorderAdjustment DisorderAdjustment Disorder With AnxietyAdjustment Disorder With Depressed MoodAdjustment Disorder With Disturbance Of ConductAdjustment Disorder With Mixed Anxiety And Depressed Mood

Showing 15 of 1,166 indications

Olanzapine brand names and reporting trend

Olanzapine is sold under brand names including Symbyax, Zyprexa Relprevv.

Brand names

Symbyax86,531
Zyprexa Relprevv1,048

Quarterly reports (2004–2025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking olanzapine with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.

Check my medications