Drugs / Acetaminophen
Acetaminophen
DrugAcetaminophen (paracetamol) is a widely used analgesic and antipyretic medicine for fever and mild to moderate pain. It is commonly sold over the counter and also appears in prescription products in some markets. Typical consumer brands include Tylenol and Panadol.
- Trials
- 1158
- Recruiting
- 64
- Completed
- 746
- With results
- 313
Last revised
Pipeline
Phase by status
| Phase | Recruiting | Not yet | By invitation | Active | Completed | Terminated | Withdrawn | Suspended | Unknown | Total |
|---|---|---|---|---|---|---|---|---|---|---|
| Early Phase 1 | 1 | 1 | — | — | 13 | 1 | 2 | — | 6 | 24 |
| Phase 1 | 5 | 3 | — | 4 | 90 | 6 | 3 | — | 5 | 116 |
| Phase 1/2 | 2 | — | — | 1 | 15 | 4 | 1 | 1 | 3 | 27 |
| Phase 2 | 9 | 3 | — | 5 | 97 | 9 | 9 | 1 | 9 | 142 |
| Phase 2/3 | 2 | 1 | — | — | 17 | 1 | 2 | — | 8 | 31 |
| Phase 3 | 8 | 3 | — | 9 | 114 | 13 | 11 | 3 | 16 | 177 |
| Phase 4 | 23 | 14 | 5 | 5 | 237 | 42 | 12 | — | 38 | 376 |
| Not applicable | 11 | 9 | — | 2 | 135 | 12 | 9 | 1 | 45 | 224 |
| Unknown | 3 | 1 | 2 | 1 | 28 | — | 2 | — | 4 | 41 |
Trials started per year
Conditions studied, by phase
| Condition | Early Phase 1 | Phase 1 | Phase 1/2 | Phase 2 | Phase 2/3 | Phase 3 | Phase 4 | Not applicable | Unknown | Total |
|---|---|---|---|---|---|---|---|---|---|---|
| Pain, Postoperative | 4 | 7 | 2 | 17 | 3 | 35 | 96 | 47 | 5 | 216 |
| Pain | 2 | 11 | — | 23 | 5 | 32 | 69 | 28 | 3 | 173 |
| Agnosia | 2 | 6 | 2 | 12 | 4 | 12 | 43 | 19 | 1 | 101 |
| Fever | — | 2 | 1 | 4 | 2 | 11 | 14 | 6 | 1 | 41 |
| Acute Pain | 1 | 3 | — | 4 | — | 10 | 16 | 3 | 1 | 38 |
| Ductus Arteriosus, Patent | — | 2 | 2 | 7 | 5 | 2 | 3 | 2 | 3 | 26 |
| Emergencies | — | — | — | 2 | — | 1 | 14 | 3 | 2 | 22 |
| Obesity | — | 16 | — | — | 1 | 1 | 1 | 2 | 1 | 22 |
| Osteoarthritis | — | 2 | 1 | 2 | — | 3 | 6 | 3 | 1 | 18 |
| Osteoarthritis, Knee | — | 1 | 1 | — | — | 5 | 3 | 7 | 1 | 18 |
Most active sponsors
| # | Sponsor | Trials | Phase 3 |
|---|---|---|---|
| 1 | GlaxoSmithKline | 24 | 8 |
| 2 | Merck Sharp & Dohme LLC | 16 | 7 |
| 3 | National Cancer Institute (NCI) | 16 | 0 |
| 4 | Montefiore Medical Center | 14 | 4 |
| 5 | Pamukkale University | 13 | 0 |
| 6 | Cairo University | 12 | 1 |
| 7 | Stanford University | 12 | 2 |
| 8 | Mallinckrodt | 11 | 7 |
| 9 | University Hospital, Clermont-Ferrand | 11 | 1 |
| 10 | Ain Shams University | 10 | 2 |
Most studied interventions
| # | Intervention | Trials |
|---|---|---|
| 1 | Acetaminophen | 1158 |
| 2 | Ibuprofen | 250 |
| 3 | Morphine | 80 |
| 4 | Oxycodone | 80 |
| 5 | Tramadol | 68 |
| 6 | Diphenhydramine | 66 |
| 7 | Dexamethasone | 58 |
| 8 | Ketorolac | 52 |
| 9 | oxycodone-acetaminophen | 50 |
| 10 | Bupivacaine | 49 |
Evidence
- Results reported
- 42%313 of 746 completed
- Published
- 11.9%89 of 746 completed
- Primary endpoint met
- 44%135 of 307 analyses
- Median months to report
- 15
Documents disclosed
Trial profile
- Median enrollment
- 80
- Median duration
- 18months
- Countries
- 87
- Study sites
- 3415
Who is enrolled
Median enrollment by phase
- Early Phase 1
- 60
- Phase 1
- 32
- Phase 1/2
- 40
- Phase 2
- 80
- Phase 2/3
- 80
- Phase 3
- 150
- Phase 4
- 90
- Not applicable
- 80
- Unknown
- 77
Where trials run
Busiest cities
| # | City | Country | Trials |
|---|---|---|---|
| 1 | New York | United States | 48 |
| 2 | Houston | United States | 37 |
| 3 | Salt Lake City | United States | 36 |
| 4 | Philadelphia | United States | 34 |
| 5 | Boston | United States | 25 |
| 6 | Cairo | Egypt | 23 |
| 7 | Columbus | United States | 23 |
| 8 | Pittsburgh | United States | 23 |
| 9 | Atlanta | United States | 22 |
| 10 | Chicago | United States | 22 |
Terminations
- Terminated
- 88
- Withdrawn
- 51
- Suspended
- 6
- Stopped for recruitment
- 3.5%40 of 1158 trials
Stated reasons
Reasons are grouped from the sponsor's own wording with a rule-based classifier; the original text is shown below.
Recently stopped
| Trial | Status | Stated reason | Stopped |
|---|---|---|---|
| NCT06689943 Suspended | Suspended | The protocol needs to be changed before enrolling | 2030-12-31 |
| NCT07625267 Withdrawn | Withdrawn | Study was never approved by the institutional review board. | 2028-06-30 |
| NCT03947671 Withdrawn | Withdrawn | Loss of funds | 2026-10-31 |
| NCT02703610 Withdrawn | Withdrawn | No participants were enrolled and the study will not be conducted. | 2026-07-30 |
| NCT05285813 Terminated | Terminated | \<75% participation | 2026-05-15 |
| NCT05088876 Terminated | Terminated | Recruitment difficulties | 2026-03-05 |
| NCT05597878 Terminated | Terminated | Study initially suspended following an audit and need of amendment to address deficiencies. PI requested to terminate due to lack of support. | 2026-02-26 |
| NCT05640674 Terminated | Terminated | After reviewing our enrollment numbers and feasibility, we have decided to close the study due to low enrollment. | 2025-12-15 |
| NCT05685225 Withdrawn | Withdrawn | No participants enrolled; study suspended due to recruitment challenges. | 2025-12-02 |
| NCT03192566 Suspended | Suspended | financial | 2025-09-30 |
Trial records
Individual study records live on ClinicalTrials.gov. A sample of the trials counted above: