Reported Reactions

Drugs › Protease inhibitor

Brand name · Nelfinavir mesylate

Viracept: adverse event reports filed with FDA

1,080 reports list it as a suspect or interacting product, 2004–2026. Class: Protease inhibitor.

1,080
reports as suspect product
0% of all reports · about 48 a year
5
reports, 12 months to June 2026
0 in the 12 months before
92.7%
marked serious by the reporter
88.5% across the class
4.4%
record death among outcomes, as reported
48 reports · not verified by FDA

Between January 2004 and June 2026, 1,080 adverse event reports received by FDA list the brand name Viracept (nelfinavir mesylate) as a suspect or interacting product. Reports that mention it only as a concomitant medication (641) are left out of every figure here.

In the 12 months to June 2026, 5 reports listed it, with none 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 48 reports a year and 0% of the 20,646,523 reports in the database, and 4.8% of the reports for the protease inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded drug exposure during pregnancy (25.4%), foetal exposure during pregnancy (16.1%) and premature baby (7.4%). A report can list several reactions, so shares add to more than 100%; 456 different terms appear across these reports. Drug exposure during pregnancy is recorded in 25.4% of these reports, a larger share than in the median protease inhibitor drug (1.4%).

92.7% of the reports are marked serious by the reporter (88.5% across the class); 4.4% record death among the outcomes and 31.6% record hospitalisation, as reported. 37.8% of the reports came from other health professionals, and the largest patient age group is 18 to 44 (28.7%). 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

023Jul 2021: 0Aug 2021: 3Sep 2021: 2Oct 2021: 3Nov 2021: 0Dec 2021: 02022Jan 2022: 2Feb 2022: 1Mar 2022: 1Apr 2022: 0May 2022: 2Jun 2022: 0Jul 2022: 0Aug 2022: 0Sep 2022: 0Oct 2022: 0Nov 2022: 0Dec 2022: 12023Jan 2023: 0Feb 2023: 0Mar 2023: 0Apr 2023: 0May 2023: 2Jun 2023: 0Jul 2023: 0Aug 2023: 0Sep 2023: 0Oct 2023: 2Nov 2023: 0Dec 2023: 02024Jan 2024: 0Feb 2024: 0Mar 2024: 0Apr 2024: 0May 2024: 0Jun 2024: 0Jul 2024: 0Aug 2024: 0Sep 2024: 0Oct 2024: 0Nov 2024: 0Dec 2024: 02025Jan 2025: 0Feb 2025: 0Mar 2025: 0Apr 2025: 0May 2025: 0Jun 2025: 0Jul 2025: 0Aug 2025: 1Sep 2025: 0Oct 2025: 0Nov 2025: 0Dec 2025: 02026Jan 2026: 0Feb 2026: 0Mar 2026: 2Apr 2026: 0May 2026: 0Jun 2026: 2

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

0621242004: 10920042005: 1172006: 1032007: 9520072008: 512009: 302010: 12420102011: 332012: 142013: 1520132014: 192015: 602016: 7420162017: 92018: 252019: 7020192020: 592021: 442022: 720222023: 42025: 12026: 42026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Viracept reports recording the termmedian drug in protease inhibitor

  1. Drug exposure during pregnancythe medicine was taken during pregnancy25.4%274
  2. Foetal exposure during pregnancythe unborn baby was exposed to the medicine16.1%174
  3. Premature babya baby born early7.4%80
  4. Anaemialow red blood cells5%54
  5. Pregnancypregnancy4.8%52
  6. Diarrhoealoose or frequent stools3.8%41
  7. Abortion spontaneousmiscarriage3.5%38
  8. Maternal exposure during pregnancythe mother took the medicine during pregnancy3.2%35
  9. Stillbirth2.8%30
  10. Vomitingbeing sick2.8%30
  11. Congenital anomalya condition present at birth2.4%26
  12. Nauseafeeling sick2.4%26
  13. Aspartate aminotransferase increasedraised liver enzyme (AST)2.3%25
  14. Neutropenialow neutrophils, a type of white blood cell2.3%25
  15. Abdominal distensiona bloated abdomen2.2%24
  16. Lipodystrophy acquiredchanges in body fat distribution2.1%23
  17. Alanine aminotransferase increasedraised liver enzyme (ALT)1.9%21
  18. Hydrocele1.8%19
  19. Fatiguetiredness1.6%17
  20. Cryptorchism1.5%16
  21. Multiple-drug resistance1.5%16

Top 30 of 456 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 median share across the 6 drugs in the protease inhibitor class; 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

Death4.4%48
Life-threatening4.5%49
Hospitalisation (initial or prolonged)31.6%341
Disability3.9%42
Congenital anomaly27.5%297
Other serious56%605
Not serious7.3%79

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 22,331 reports in the class. 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

Under 211.9%129
2 to 111.1%12
12 to 170.2%2
18 to 4428.7%310
45 to 6413.9%150
65 to 740.9%10
75 and over0.4%4
Age not given42.9%463

Patient sex

Female39.4%426
Male51.1%552
Not given9.4%102

Who reported

Physician29.4%318
Pharmacist2.5%27
Other health professional37.8%408
Lawyer1%11
Consumer or non-health professional22.9%247
Not given6.4%69

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 35.5% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Hiv infection54050%
Hiv test positive847.8%
Antiretroviral therapy222%
Acquired immunodeficiency syndrome191.8%
Prophylaxis against HIV infection131.2%
Drug exposure during pregnancy111%

The indication field is filled in by the reporter and is often blank; shares are of all 1,080 reports.

In context

MeasureViraceptProtease inhibitorAll reports
Reports as suspect product1,08022,33120,646,523
Share of that pool—4.8%0%
Reports, latest 12 months5—1,332,454
Marked serious92.7%88.5%57.4%
Death recorded among outcomes, per 1,000 reports448891
Hospitalisation recorded, per 1,000 reports316279213
Consumer-filed share22.9%19.5%45.8%
Top term, share of reportsDrug exposure during pregnancy 25.4%median 1.4%0.2%

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."

Other drugs in the protease inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Prezistabrand6,26412882%
Reyatazbrand5,181583.9%
Darunavirgeneric4,4608694.4%
Atazanavirgeneric2,7252894%
Atazanavir sulfategeneric2,6212295.3%

Ordered by report count for navigation only. 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." A brand and its generic are separate rows because reporters name them separately.

Questions about Viracept reports

How many adverse event reports has FDA received for Viracept?

1,080 reports list Viracept as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 5 of them arrived in the latest 12 months. Another 641 list it only as a concomitant medication.

What reactions are recorded in Viracept reports?

drug exposure during pregnancy (25.4%), foetal exposure during pregnancy (16.1%), premature baby (7.4%), caesarean section (5.1%) and anaemia (5%). 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 Viracept was responsible.

How serious are the reports?

92.7% are marked serious by the reporter. Among the outcomes recorded, 4.4% of reports include death and 31.6% 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 (37.8%), physician (29.4%) and consumer or non-health professional (22.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Viracept rising?

5 reports in the 12 months to June 2026, with none 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 Viracept 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 Viracept?

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 Viracept as a suspect or interacting product; reports listing it only as a concomitant medication (641) 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.