Product name as reported
Nirmatrelvir Ritonavir: adverse event reports filed with FDA
1,603 reports list it as a suspect or interacting product, 2022–2026.
- 1,603
- reports as suspect product
- 0% of all reports · about 357 a year
- 43
- reports, 12 months to June 2026
- 160 in the 12 months before
- 67.5%
- marked serious by the reporter
- 57.4% across all reports
- 2.7%
- record death among outcomes, as reported
- 44 reports · not verified by FDA
Between January 2022 and May 2026, 1,603 adverse event reports received by FDA list the product name "Nirmatrelvir Ritonavir" as reporters wrote it as a suspect or interacting product. Reports that mention it only as a concomitant medication (153) are left out of every figure here.
In the 12 months to June 2026, 43 reports listed it, down 73% from 160 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 357 reports a year and 0% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.
The reactions recorded most often are drug interaction (19.8%), off label use (11.9%) and diarrhoea (9.1%). A report can list several reactions, so shares add to more than 100%; 271 different terms appear across these reports. Drug interaction is recorded in 19.8% of these reports, against 0.8% of all reports in the database.
67.5% of the reports are marked serious by the reporter; 2.7% record death among the outcomes and 32.3% record hospitalisation, as reported. 57.8% of the reports came from other health professionals, and the largest patient age group is 75 and over (34%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Nirmatrelvir Ritonavir reports recording the termall reports in the database
- Drug interactionan interaction between medicines19.8%318
- Off label useused for a purpose or in a way not on the label11.9%191
- Diarrhoealoose or frequent stools9.1%146
- Acute kidney injurysudden loss of kidney function9%145
- Covid-19COVID-19 infection8.9%143
- Toxicity to various agentspoisoning or toxic effect of one or more substances8.7%139
- Nauseafeeling sick8.2%131
- Dysgeusiaaltered taste7.6%122
- Hepatic function abnormal7.2%115
- Vomitingbeing sick6.7%108
- Overdosea dose above the recommended amount5.5%88
- Incorrect dose administeredthe wrong dose was given4.5%72
- Drug level increaseda raised blood level of the medicine4.1%65
- Rashskin rash3.6%57
- Immunosuppressant drug level increased3.4%55
- Dizzinesslight-headedness or unsteadiness3.2%52
- Headachehead pain3%48
- Inappropriate schedule of product administrationthe product was taken at the wrong times3%48
- Alanine aminotransferase increasedraised liver enzyme (ALT)2.6%42
- Blood creatinine increasedraised creatinine, a kidney test2.6%42
- Taste disorder2.5%40
- Liver injury2.4%38
- Renal impairmentreduced kidney function2.4%38
- Hepatic enzyme increasedraised liver enzymes2.3%37
- Transaminases increased2.2%35
- Abdominal painstomach or belly pain2.1%33
- Drug ineffectivethe medicine did not work as expected2.1%33
- Aspartate aminotransferase increasedraised liver enzyme (AST)2%32
- Pruritusitching1.8%29
Top 30 of 271 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the share of all reports in the database; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 43.3% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Covid-19 | 659 | 41.1% |
| Covid-19 treatment | 435 | 27.1% |
| Coronavirus infection | 54 | 3.4% |
| Upper respiratory tract infection | 53 | 3.3% |
| Antiviral treatment | 52 | 3.2% |
| Pneumonia viral | 38 | 2.4% |
The indication field is filled in by the reporter and is often blank; shares are of all 1,603 reports.
In context
| Measure | Nirmatrelvir Ritonavir | All reports |
|---|---|---|
| Reports as suspect product | 1,603 | 20,646,523 |
| Share of that pool | — | 0% |
| Reports, latest 12 months | 43 | 1,332,454 |
| Marked serious | 67.5% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 27 | 91 |
| Hospitalisation recorded, per 1,000 reports | 323 | 213 |
| Consumer-filed share | 1.9% | 45.8% |
| Top term, share of reports | Drug interaction 19.8% | 0.8% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Questions about Nirmatrelvir Ritonavir reports
How many adverse event reports has FDA received for Nirmatrelvir Ritonavir?
1,603 reports list Nirmatrelvir Ritonavir as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 43 of them arrived in the latest 12 months. Another 153 list it only as a concomitant medication.
What reactions are recorded in Nirmatrelvir Ritonavir reports?
drug interaction (19.8%), off label use (11.9%), diarrhoea (9.1%), acute kidney injury (9%) and covid-19 (8.9%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Nirmatrelvir Ritonavir was responsible.
How serious are the reports?
67.5% are marked serious by the reporter. Among the outcomes recorded, 2.7% of reports include death and 32.3% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
other health professional (57.8%), pharmacist (24.5%) and physician (15.5%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Nirmatrelvir Ritonavir rising?
43 reports in the 12 months to June 2026, down 73% from 160 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Nirmatrelvir Ritonavir was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Nirmatrelvir Ritonavir?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Nirmatrelvir Ritonavir as a suspect or interacting product; reports listing it only as a concomitant medication (153) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.