NIRMATRELVIR AND RITONAVIR

35/100 · Moderate

Manufactured by Pfizer Laboratories Div Pfizer Inc

Nirmatrelvir and Ritonavir Adverse Events: Mostly Non-Serious, with Common Gastrointestinal Reactions

110,406 FDA adverse event reports analyzed

Last updated: 2026-05-12

About NIRMATRELVIR AND RITONAVIR

NIRMATRELVIR AND RITONAVIR is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by Pfizer Laboratories Div Pfizer Inc. Based on analysis of 110,406 FDA adverse event reports, NIRMATRELVIR AND RITONAVIR has a safety score of 35 out of 100. This lower score reflects a significant number of adverse event reports, suggesting that patients should discuss potential risks carefully with their healthcare provider. The most commonly reported adverse reactions for NIRMATRELVIR AND RITONAVIR include COVID-19, DISEASE RECURRENCE, DYSGEUSIA, DIARRHOEA, NAUSEA. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for NIRMATRELVIR AND RITONAVIR.

AI Safety Analysis

Nirmatrelvir And Ritonavir has a safety concern score of 35 out of 100, placing it in the moderate concern category based on analysis of FDA adverse event data. The FDA has received approximately 110,406 adverse event reports for this medication, which is primarily manufactured by Pfizer Laboratories Div Pfizer Inc.

The most commonly reported adverse events include Covid-19, Disease Recurrence, Dysgeusia. Of classified reports, 17.8% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. The majority of adverse events are non-serious, with gastrointestinal issues being the most common.

Disease recurrence and incorrect dose administration are significant safety concerns. Drug interactions and prescribing errors are reported but less frequent. Serious adverse events account for about 17.8% of total reports, with respiratory issues being notable. The adverse event profile is dominated by common symptoms like nausea, diarrhea, and fatigue.

Patients taking Nirmatrelvir And Ritonavir should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Drug interactions and prescribing errors are common, with warnings to avoid certain medications and to follow the prescribed schedule strictly. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.

Safety Score: 35/100

Nirmatrelvir And Ritonavir received a safety concern score of 35/100 (moderate concern). This is based on a 17.8% serious event ratio across 53,109 classified reports. The score accounts for 110,406 total adverse event reports and 100 distinct reaction types. This moderate score is typical for widely prescribed medications with established safety profiles.

Top Adverse Reactions

COVID 1922,774 reports
DISEASE RECURRENCE20,089 reports
DYSGEUSIA7,316 reports
DIARRHOEA4,003 reports
NAUSEA2,620 reports
HEADACHE2,156 reports
COUGH2,041 reports
FATIGUE2,006 reports
INCORRECT DOSE ADMINISTERED1,691 reports
VOMITING1,384 reports
NASAL CONGESTION1,366 reports
MALAISE1,362 reports
OFF LABEL USE1,300 reports
DRUG INTERACTION1,250 reports
OROPHARYNGEAL PAIN1,247 reports
PYREXIA1,245 reports
DIZZINESS1,191 reports
RHINORRHOEA1,088 reports
THERAPEUTIC PRODUCT EFFECT INCOMPLETE1,072 reports
PAIN1,053 reports
TASTE DISORDER1,040 reports
SYMPTOM RECURRENCE992 reports
FEELING ABNORMAL968 reports
INSOMNIA864 reports
ILLNESS832 reports
ABDOMINAL PAIN UPPER809 reports
INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION743 reports
DYSPNOEA737 reports
INCORRECT PRODUCT ADMINISTRATION DURATION733 reports
RASH733 reports
ASTHENIA702 reports
PRODUCT PRESCRIBING ERROR670 reports
CONTRAINDICATED PRODUCT ADMINISTERED667 reports
ABDOMINAL DISCOMFORT660 reports
DECREASED APPETITE633 reports
SARS COV 2 TEST POSITIVE628 reports
PRODUCT USE ISSUE600 reports
PRURITUS567 reports
PRODUCT TASTE ABNORMAL562 reports
MYALGIA512 reports
NASOPHARYNGITIS503 reports
ABDOMINAL PAIN495 reports
SNEEZING478 reports
DRUG INEFFECTIVE470 reports
URTICARIA454 reports
WRONG TECHNIQUE IN PRODUCT USAGE PROCESS450 reports
CONDITION AGGRAVATED435 reports
CHILLS407 reports
HYPERTENSION401 reports
PRODUCT DOSE OMISSION ISSUE398 reports
DYSPHAGIA395 reports
DRY MOUTH388 reports
DYSPHONIA368 reports
AGEUSIA363 reports
ACUTE KIDNEY INJURY362 reports
THERAPEUTIC RESPONSE UNEXPECTED357 reports
REBOUND EFFECT342 reports
ARTHRALGIA333 reports
WEIGHT DECREASED329 reports
INTENTIONAL PRODUCT MISUSE326 reports
BLOOD PRESSURE INCREASED311 reports
MUSCLE SPASMS311 reports
PRODUCT DISPENSING ERROR306 reports
HYPERHIDROSIS304 reports
ANXIETY294 reports
CHEST DISCOMFORT285 reports
CHEST PAIN284 reports
HYPERSENSITIVITY280 reports
DYSPEPSIA278 reports
TOXICITY TO VARIOUS AGENTS278 reports
DEHYDRATION276 reports
BACK PAIN274 reports
TREMOR272 reports
PAIN IN EXTREMITY259 reports
THROAT IRRITATION257 reports
PRODUCT USE COMPLAINT252 reports
PALPITATIONS242 reports
ANOSMIA230 reports
PRODUCTIVE COUGH230 reports
SOMNOLENCE229 reports
EXPIRED PRODUCT ADMINISTERED227 reports
ERYTHEMA223 reports
HYPOTENSION221 reports
SINUSITIS215 reports
DRUG HYPERSENSITIVITY210 reports
PNEUMONIA210 reports
GASTROINTESTINAL DISORDER205 reports
CONFUSIONAL STATE204 reports
HEART RATE INCREASED204 reports
FALL198 reports
GASTROOESOPHAGEAL REFLUX DISEASE196 reports
DEATH194 reports
PARAESTHESIA193 reports
VISION BLURRED193 reports
THROAT TIGHTNESS192 reports
SINUS CONGESTION188 reports
IMMUNOSUPPRESSANT DRUG LEVEL INCREASED184 reports
LOSS OF CONSCIOUSNESS180 reports
GAIT DISTURBANCE179 reports
BRADYCARDIA178 reports

Key Safety Signals

  • High frequency of incorrect dose administration and product misuse.
  • Significant number of reports related to drug interactions and prescribing errors.
  • Respiratory symptoms like cough and dyspnea are notable among serious events.
  • Gastrointestinal issues are the most common adverse events, with diarrhea and nausea being frequent.
  • Serious adverse events include respiratory issues, kidney injury, and death.

Patient Demographics

Adverse event reports by sex: Female: 30,853, Male: 16,849, Unknown: 64. The most frequently reported age groups are age 68 (1,343 reports), age 70 (1,337 reports), age 69 (1,287 reports). These demographics reflect reporting patterns and may not represent the full patient population.

Report Outcomes

Out of 53,109 classified reports for NIRMATRELVIR AND RITONAVIR:

  • Serious: 9,454 reports (17.8%) — includes hospitalization, disability, life-threatening events, or death
  • Non-Serious: 43,655 reports (82.2%)
Serious 17.8%Non-Serious 82.2%

The FDA classifies an adverse event as “serious” if it results in death, hospitalization, disability, congenital anomaly, or requires intervention to prevent permanent damage.

Demographics Breakdown

Reports by Sex

Female30,853 (64.6%)
Male16,849 (35.3%)
Unknown64 (0.1%)

Reports by Age

Age 681,343 reports
Age 701,337 reports
Age 691,287 reports
Age 651,269 reports
Age 661,266 reports
Age 711,233 reports
Age 671,230 reports
Age 721,187 reports
Age 641,030 reports
Age 731,006 reports
Age 62994 reports
Age 63966 reports
Age 61937 reports
Age 60934 reports
Age 74910 reports
Age 75901 reports
Age 59883 reports
Age 58808 reports
Age 57783 reports
Age 55777 reports

Demographics reflect voluntary FDA adverse event reporting patterns and may not represent the full patient population.

Drug Interactions & Warnings

Drug interactions and prescribing errors are common, with warnings to avoid certain medications and to follow the prescribed schedule strictly.

What You Should Know

If you are taking Nirmatrelvir And Ritonavir, here are important things to know. The most commonly reported side effects include covid-19, disease recurrence, dysgeusia, diarrhoea, nausea. While many of these may be mild and temporary, you should contact your healthcare provider if any symptoms are severe or persistent. Follow the prescribed dose and schedule strictly to avoid incorrect dose administration. Be cautious of potential drug interactions and consult a healthcare provider before combining with other medications. If you experience a serious adverse reaction, seek emergency medical attention immediately or call 911. You can report side effects to the FDA's MedWatch program at 1-800-FDA-1088.

Regulatory Context

The FDA continues to monitor the safety of Nirmatrelvir and Ritonavir, with ongoing reviews of adverse event reports.

Frequently Asked Questions

How many adverse event reports has the FDA received for Nirmatrelvir And Ritonavir?

The FDA has received approximately 110,406 adverse event reports associated with Nirmatrelvir And Ritonavir. These reports come from healthcare professionals, consumers, and manufacturers through the FDA Adverse Event Reporting System (FAERS). Note that the number of reports does not directly indicate the frequency of side effects, as adverse events are voluntarily reported and may be underrepresented.

What are the most commonly reported side effects of Nirmatrelvir And Ritonavir?

The most frequently reported adverse events for Nirmatrelvir And Ritonavir include Covid-19, Disease Recurrence, Dysgeusia, Diarrhoea, Nausea. By volume, the top reported reactions are: Covid-19 (22,774 reports), Disease Recurrence (20,089 reports), Dysgeusia (7,316 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Nirmatrelvir And Ritonavir.

What percentage of Nirmatrelvir And Ritonavir adverse event reports are serious?

Out of 53,109 classified reports, 9,454 (17.8%) were classified as serious and 43,655 as non-serious. The FDA classifies an event as "serious" if it results in death, hospitalization, disability, or other medically significant outcomes. A higher serious-event ratio warrants closer attention but does not necessarily mean the drug is unsafe.

Who reports adverse events for Nirmatrelvir And Ritonavir (by sex)?

Adverse event reports for Nirmatrelvir And Ritonavir break down by patient sex as follows: Female: 30,853, Male: 16,849, Unknown: 64. This distribution reflects reporting patterns rather than actual risk differences between groups. Reporting rates can be influenced by prescribing patterns, disease demographics, and reporting behavior.

What age groups report the most side effects for Nirmatrelvir And Ritonavir?

The most frequently reported age groups for Nirmatrelvir And Ritonavir adverse events are: age 68: 1,343 reports, age 70: 1,337 reports, age 69: 1,287 reports, age 65: 1,269 reports, age 66: 1,266 reports. Age-related reporting patterns can reflect both the demographics of the patient population and potential age-related susceptibility to certain side effects.

Who manufactures Nirmatrelvir And Ritonavir?

The primary manufacturer associated with Nirmatrelvir And Ritonavir adverse event reports is Pfizer Laboratories Div Pfizer Inc. Multiple manufacturers may produce generic versions of this drug. The manufacturer listed reflects the most frequently reported brand in FDA adverse event data.

What other side effects have been reported for Nirmatrelvir And Ritonavir?

Beyond the most common reactions, other reported adverse events for Nirmatrelvir And Ritonavir include: Headache, Cough, Fatigue, Incorrect Dose Administered, Vomiting. Less common side effects can still be clinically significant. Patients should report any unusual symptoms to their healthcare provider.

How do I report a side effect from Nirmatrelvir And Ritonavir?

You can report adverse events from Nirmatrelvir And Ritonavir to the FDA through their MedWatch program at www.fda.gov/medwatch, by calling 1-800-FDA-1088, or by completing Form FDA 3500. Healthcare professionals, consumers, and manufacturers can all submit reports. Reporting helps the FDA monitor drug safety after approval.

What is Nirmatrelvir And Ritonavir's safety score and what does it mean?

Nirmatrelvir And Ritonavir has a safety concern score of 35 out of 100 (moderate concern). This score is calculated from the ratio of serious to non-serious adverse events, the diversity of reported reactions, and the overall volume of reports relative to usage. The majority of adverse events are non-serious, with gastrointestinal issues being the most common.

What are the key safety signals for Nirmatrelvir And Ritonavir?

Key safety signals identified in Nirmatrelvir And Ritonavir's adverse event data include: High frequency of incorrect dose administration and product misuse.. Significant number of reports related to drug interactions and prescribing errors.. Respiratory symptoms like cough and dyspnea are notable among serious events.. Gastrointestinal issues are the most common adverse events, with diarrhea and nausea being frequent.. Serious adverse events include respiratory issues, kidney injury, and death.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.

Does Nirmatrelvir And Ritonavir interact with other drugs?

Drug interactions and prescribing errors are common, with warnings to avoid certain medications and to follow the prescribed schedule strictly. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Nirmatrelvir And Ritonavir.

What should patients know before taking Nirmatrelvir And Ritonavir?

Follow the prescribed dose and schedule strictly to avoid incorrect dose administration. Be cautious of potential drug interactions and consult a healthcare provider before combining with other medications.

Are Nirmatrelvir And Ritonavir side effects well-documented?

Nirmatrelvir And Ritonavir has 110,406 adverse event reports on file with the FDA. Disease recurrence and incorrect dose administration are significant safety concerns. The volume of reports for Nirmatrelvir And Ritonavir reflects both the drug's usage level and the vigilance of the reporting community.

What is the FDA's position on Nirmatrelvir And Ritonavir?

The FDA continues to monitor the safety of Nirmatrelvir and Ritonavir, with ongoing reviews of adverse event reports. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.

Related Drugs

Drugs related to NIRMATRELVIR AND RITONAVIR based on therapeutic use, drug class, or shared indications:

NirmatrelvirRitonavirOther antiviralsImmunosuppressantsRespiratory medications
Important Disclaimer: This content is generated by AI analysis of FDA adverse event reports and is provided for informational purposes only. It is not medical advice. Adverse event reports submitted to the FDA do not prove that a medication caused the reported side effect. Always consult your healthcare provider before starting, stopping, or changing any medication. If you experience a serious side effect, contact your doctor or call 911 immediately.