Pharmacologic class (EPC) · 4 drug pages

Antimetabolite immunosuppressant: adverse event reports filed with FDA

121,804 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

121,804
reports across the class: 0.6% of all reports; 12,584
reports, 12 months to June 2026: 12,639 in the 12 months before; 92.4%
marked serious by the reporter: 57.4% across all reports; 4
drugs with a page: brand and generic names counted separately

Antimetabolite immunosuppressant is a pharmacologic class (an FDA Established Pharmacologic Class) with 4 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 121,804 adverse event reports received by FDA, 0.6% of the database, from January 2004 to June 2026.

12,584 reports arrived in the 12 months to June 2026, close to the 12,639 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 92.4% of the class's reports are marked serious, 18.8% record death among the outcomes and 38.4% record hospitalisation, as reported.

Across the class the reactions recorded most often are off label use (14.9%), drug ineffective (8.8%) and product use in unapproved indication (5.8%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Mycophenolate mofetil	generic	82,125	9,692	93.7%	Off label use
CellCeptMycophenolate mofetil	brand	17,983	941	88%	Off label use
Mycophenolic acid	generic	13,844	1,632	96.3%	Off label use
MyforticMycophenolic acid	brand	7,852	319	82%	Diarrhoea

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Off label useused for a purpose or in a way not on the label14.9%18,159
Drug ineffectivethe medicine did not work as expected8.8%10,704
Product use in unapproved indicationused for a purpose not on the label5.8%7,125
Diarrhoealoose or frequent stools5.3%6,431
Pyrexiafever4.3%5,285
Cytomegalovirus infection4.1%5,044
Pneumonialung infection3.9%4,755
Condition aggravatedthe condition being treated got worse3.4%4,090
Transplant rejection3.3%4,023
Covid-19COVID-19 infection3%3,692
Nauseafeeling sick3%3,618
Fatiguetiredness2.9%3,550
Infectionan infection, type not specified2.9%3,518
Vomitingbeing sick2.9%3,501
Acute kidney injurysudden loss of kidney function2.9%3,475
Deaththe patient died; cause not stated by this term2.8%3,392
Sepsisa severe body-wide response to infection2.7%3,241
Dyspnoeashortness of breath2.6%3,174
Headachehead pain2.5%2,999
Hypertensionhigh blood pressure2.4%2,951
Treatment failurethe treatment did not work2.4%2,929
Intentional product use issuedeliberate use not as intended2.2%2,706
Drug intolerancethe medicine was not tolerated2.2%2,675
Neutropenialow neutrophils, a type of white blood cell2.2%2,668
Malaisegeneral feeling of being unwell2.2%2,646

Solid bar: share of all class reports. Hollow bar: the median share across the 4 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death18.8%22,946

Life-threatening9.8%11,974

Hospitalisation (initial or prolonged)38.4%46,799

Disability3.1%3,729

Congenital anomaly1.2%1,413

Other serious66.5%80,972

Not serious7.6%9,255

Patient age

Under 20.9%1,110

2 to 114.2%5,091

12 to 173.3%3,969

18 to 4421.4%26,058

45 to 6428.7%34,946

65 to 7410.8%13,112

75 and over2.9%3,564

Age not given27.9%33,954

Who reported

Physician31.9%38,800

Pharmacist3.7%4,507

Other health professional50.1%60,978

Lawyer0%28

Consumer or non-health professional12%14,600

Not given2.4%2,891

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Antimetabolite immunosuppressant reports

Which drugs are in the Antimetabolite immunosuppressant class on this site?

Mycophenolate mofetil, CellCept, Mycophenolic acid and Myfortic. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

121,804 reports through June 2026, 12,584 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

off label use (14.9%), drug ineffective (8.8%), product use in unapproved indication (5.8%), diarrhoea (5.3%) and pyrexia (4.3%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. 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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.