OpenClaim

Acetylcysteine Side Effects

The most commonly reported side effects of acetylcysteine include dyspnoea, off label use, and pneumonia, based on 11,629 FDA adverse event reports from 2004 to 2025. 6.1% of reports found the drug to be ineffective.

Acetylcysteine side effects

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

1
Dyspnoea6.8%791
2
Off Label Use6.1%713
3
Drug Ineffective6.1%710
4
Pneumonia5.6%648
5
Pyrexia4.0%460
6
Fatigue3.9%457
7
Acute Kidney Injury3.7%436
8
Nausea3.6%420
9
Cough3.1%358
10
Hypertension3.0%354
11
Diarrhoea3.0%345
12
Chronic Obstructive Pulmonary Disease2.9%339
13
Death2.7%315
14
Vomiting2.7%311
15
Toxicity To Various Agents2.6%301

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

Report severity

89.3%Serious10,388 reports
53.8%Hospitalizations6,254 reports
18.5%Fatal2,151 reports

Seriousness is determined by the reporter, not by OpenClaim.

Acetylcysteine drug interactions

Other drugs that appear in adverse event reports alongside acetylcysteine. 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
Acetaminophen6.6%765
2
Prednisone4.2%494
3
Aspirin3.2%375
4
Budesonide2.9%342
5
Amlodipine2.8%320
6
Carboplatin2.7%309
7
Methylprednisolone2.6%302
8
Azithromycin2.6%301
9
Albuterol2.6%297
10
Rituximab2.5%292
11
Furosemide2.4%278
12
Omeprazole2.3%270
13
Pregabalin2.2%258
14
Dexamethasone2.1%250
15
Pantoprazole-sodium2.1%248

Taken alongside

1
Acetaminophen17.4%2,021
2
Albuterol16.4%1,904
3
Furosemide14.1%1,636
4
Omeprazole13.0%1,509
5
Aspirin11.3%1,314
6
Pantoprazole-sodium10.7%1,247
7
Prednisone8.7%1,010
8
Ipratropium-bromide8.5%994
9
Budesonide8.3%966
10
Ergocalciferol8.1%947
11
Sodium-chloride7.5%869
12
Potassium-chloride7.4%865
13
Atorvastatin-calcium7.4%861
14
Amlodipine7.3%847
15
Levothyroxine-sodium7.2%840

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 acetylcysteine side effects

46.4% of acetylcysteine adverse event reports involve female patients and 43.9% involve male patients. The largest age group is adult at 49%. These figures reflect who reports side effects, not underlying risk.

Sex

Female46.4%
Male43.9%
Unknown9.7%

Age group

< 21.5%
2–112.8%
12–173.8%
18–6448.6%
65+43.3%

What is acetylcysteine used for

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

Abdominal DiscomfortAccidental Exposure To ProductAccidental OverdoseAcute Hepatic FailureAcute Kidney InjuryAcute Respiratory Distress SyndromeAcute Upper Respiratory Tract InfectionAdverse EventAffective DisorderAlanine Aminotransferase IncreasedAlcohol PoisoningAlkalosisAmyotrophic Lateral SclerosisAnalgesic Drug LevelAnalgesic Drug Level Increased

Showing 15 of 622 indications

Acetylcysteine brand names and reporting trend

Acetylcysteine is sold under brand names including Mucosil-10, Legubeti.

Brand names

Mucosil-1011,679
Legubeti389

Quarterly reports (20042025)

20052010201520202025

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

Taking acetylcysteine with another medication?

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