OpenClaim

Mepolizumab Side Effects

The most commonly reported side effects of mepolizumab include asthma, dyspnoea, and wheezing, based on 47,245 FDA adverse event reports from 2008 to 2025. 9.3% of reports found the drug to be ineffective.

Mepolizumab side effects

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

1
Asthma26.3%12,421
2
Dyspnoea21.6%10,203
3
Wheezing14.6%6,905
4
Product Dose Omission Issue13.1%6,194
5
Cough10.5%4,939
6
Therapeutic Product Effect Incomplete10.4%4,917
7
Pneumonia9.4%4,422
8
Drug Ineffective9.3%4,408
9
Loss Of Personal Independence In Daily Activities8.8%4,149
10
Sleep Disorder Due To A General Medical Condition6.4%3,042
11
Off Label Use6.2%2,932
12
Fatigue6.2%2,919
13
Malaise5.6%2,633
14
Condition Aggravated5.5%2,605
15
Headache5.3%2,527

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

Report severity

63.1%Serious29,806 reports
32.1%Hospitalizations15,177 reports
7.5%Fatal3,555 reports

Seriousness is determined by the reporter, not by OpenClaim.

Mepolizumab drug interactions

Other drugs that appear in adverse event reports alongside mepolizumab. 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
Albuterol16.9%8,007
2
Prednisone12.9%6,072
3
Fluticasone11.0%5,183
4
Budesonide10.4%4,928
5
Tiotropium-bromide10.3%4,880
6
Montelukast-sodium8.7%4,131
7
Formoterol7.5%3,521
8
Ciclesonide5.2%2,443
9
Salmeterol-xinafoate4.9%2,297
10
Vilanterol-trifenatate4.7%2,242
11
Cetirizine-hydrochloride3.6%1,702
12
Ipratropium-bromide3.6%1,701
13
Candesartan-cilexetil3.5%1,677
14
Acetaminophen3.5%1,630
15
Abatacept3.4%1,604

Taken alongside

1
Albuterol8.3%3,938
2
Prednisone6.6%3,130
3
Fluticasone5.2%2,459
4
Budesonide5.1%2,388
5
Montelukast-sodium4.9%2,292
6
Tiotropium-bromide4.6%2,188
7
Formoterol4.4%2,071
8
Vilanterol-trifenatate2.3%1,100
9
Pantoprazole-sodium2.1%993
10
Ergocalciferol1.9%911
11
Acetaminophen1.9%908
12
Salmeterol-xinafoate1.9%897
13
Umeclidinium-bromide1.6%740
14
Levothyroxine-sodium1.5%728
15
Calcium1.5%718

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 mepolizumab side effects

49.2% of mepolizumab adverse event reports involve female patients and 23.4% involve male patients. The largest age group is adult at 59%. These figures reflect who reports side effects, not underlying risk.

Sex

Female49.2%
Male23.4%
Unknown27.5%

Age group

< 20.3%
2–110.7%
12–170.8%
18–6459.4%
65+38.8%

What is mepolizumab used for

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

Adjuvant TherapyAlcoholismAllergic Granulomatous AngiitisAnaphylactic ReactionAngioimmunoblastic T-cell LymphomaAntiphospholipid SyndromeAortic StenosisArthralgiaArthropathyAspergillus InfectionAspirin-exacerbated Respiratory DiseaseAsthmaAsthma Late OnsetAsthma ProphylaxisAsthma-chronic Obstructive Pulmonary Disease Overlap Syndrome

Showing 15 of 647 indications

Mepolizumab brand names and reporting trend

Mepolizumab is sold under the brand name Nucala.

Brand names

Nucala29,744

Quarterly reports (20082025)

200820202025

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

Taking mepolizumab with another medication?

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