Most Commonly Reported Adverse Reactions

These are the most commonly reported adverse reactions across all drugs in the FAERS database. Common reactions like fatigue, nausea, and headache appear frequently because they are associated with many different medications and are easily recognized by patients.

# Reaction ↕ Total Reports ↕ Drugs Reporting ↕
1 FATIGUE 11,561,068 499
2 OFF LABEL USE 10,077,442 500
3 DRUG INEFFECTIVE 9,988,325 500
4 NAUSEA 9,822,201 499
5 PAIN 8,854,826 500
6 DYSPNOEA 8,799,278 499
7 DIARRHOEA 8,555,594 499
8 HEADACHE 8,339,258 499
9 ARTHRALGIA 7,020,968 490
10 VOMITING 6,887,655 497
11 DIZZINESS 6,403,566 491
12 PYREXIA 6,145,506 484
13 PNEUMONIA 6,004,227 498
14 RASH 5,942,908 497
15 ASTHENIA 5,852,679 491
16 MALAISE 5,427,042 498
17 FALL 5,335,583 479
18 DEATH 4,999,372 476
19 PRURITUS 4,846,888 468
20 TOXICITY TO VARIOUS AGENTS 4,246,942 294
21 CONDITION AGGRAVATED 3,236,806 320
22 INFUSION RELATED REACTION 3,176,492 296
23 RHEUMATOID ARTHRITIS 3,059,530 305
24 JOINT SWELLING 2,910,261 309
25 NASOPHARYNGITIS 2,875,256 310
26 WEIGHT INCREASED 2,537,491 294
27 HYPERTENSION 2,510,977 302
28 PAIN IN EXTREMITY 2,401,221 207
29 SINUSITIS 2,353,744 283
30 HYPERSENSITIVITY 2,295,819 284
31 COMPLETED SUICIDE 2,229,822 279
32 WEIGHT DECREASED 2,141,270 188
33 COUGH 2,096,822 186
34 MYOCARDIAL INFARCTION 1,884,360 135
35 CONSTIPATION 1,707,947 174
36 ANAEMIA 1,605,375 144
37 GASTROINTESTINAL HAEMORRHAGE 1,600,979 131
38 HYPOTENSION 1,572,981 151
39 CHEST PAIN 1,555,298 135
40 FLUSHING 1,505,682 131
41 CEREBROVASCULAR ACCIDENT 1,388,670 132
42 ACUTE KIDNEY INJURY 546,196 51
43 CHRONIC KIDNEY DISEASE 466,244 39
44 ALOPECIA 302,488 23
45 DECREASED APPETITE 300,334 45
46 BACK PAIN 286,799 39
47 ABDOMINAL PAIN 277,458 35
48 RENAL FAILURE 272,647 37
49 ABDOMINAL DISCOMFORT 272,471 21
50 DRUG INTERACTION 263,688 34

Key Takeaways

  • The most common reactions tend to be general symptoms (fatigue, pain, nausea) that occur with many different drugs.
  • High report counts for a reaction reflect how many drugs can trigger it, not necessarily severity.
  • The "drugs reporting" column shows how many different medications have been associated with each reaction.

Important Disclaimer

FDA adverse event reports are submitted voluntarily and do not prove causation. A reported reaction does not mean the drug caused it. Drugs with more users naturally have more reports. These rankings reflect reporting volume, not drug safety. Always consult your doctor or pharmacist before making medication decisions.