Pharmacologic class (EPC) · 3 drug pages

Folate analog: adverse event reports filed with FDA

16,736 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.

16,736
reports across the class: 0.1% of all reports; 1,416
reports, 12 months to June 2026: 1,469 in the 12 months before; 94.8%
marked serious by the reporter: 57.4% across all reports; 3
drugs with a page: brand and generic names counted separately

Folate analog is a pharmacologic class (an FDA Established Pharmacologic Class) with 3 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 16,736 adverse event reports received by FDA, 0.1% of the database, from January 2004 to June 2026.

1,416 reports arrived in the 12 months to June 2026, close to the 1,469 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 94.8% of the class's reports are marked serious, 15.4% record death among the outcomes and 47.3% record hospitalisation, as reported.

Across the class the reactions recorded most often are diarrhoea (10.1%), neutropenia (7.3%) and nausea (7.3%). 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
Leucovorin calcium	generic	11,894	1,211	93.3%	Diarrhoea
Calcium folinate	generic	3,359	0	98.5%	Diarrhoea
Levoleucovorin calcium	generic	1,483	205	99.1%	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

Diarrhoealoose or frequent stools10.1%1,693
Neutropenialow neutrophils, a type of white blood cell7.3%1,218
Nauseafeeling sick7.3%1,215
Vomitingbeing sick6.3%1,052
Pyrexiafever5.1%856
Fatiguetiredness4.6%777
Disease progressionthe disease advanced4.6%772
Neuropathy peripheralnerve damage in hands or feet4.5%758
Febrile neutropeniafever with low white blood cells4.3%725
Thrombocytopenialow platelets3.7%622
Off label useused for a purpose or in a way not on the label3.6%608
Abdominal painstomach or belly pain3.6%598
Dehydrationdehydration3.2%531
Anaemialow red blood cells3.2%528
Astheniaweakness or lack of energy3%505
Sepsisa severe body-wide response to infection2.8%469
Pulmonary embolisma blood clot in the lung2.6%432
Decreased appetitereduced appetite2.6%431
Dyspnoeashortness of breath2.5%415
Drug ineffectivethe medicine did not work as expected2.4%407
Deaththe patient died; cause not stated by this term2.3%392
Mucosal inflammation2.3%378
Hypertensionhigh blood pressure2.3%377
Malignant neoplasm progression2.2%376
Pneumonialung infection2.2%362

Solid bar: share of all class reports. Hollow bar: the median share across the 3 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death15.4%2,581

Life-threatening7.6%1,265

Hospitalisation (initial or prolonged)47.3%7,913

Disability1.5%245

Congenital anomaly0.5%89

Other serious52.6%8,808

Not serious5.2%864

Patient age

Under 20.5%81

2 to 111.4%227

12 to 170.7%120

18 to 447.6%1,268

45 to 6430.5%5,101

65 to 7421.8%3,656

75 and over8.5%1,419

Age not given29.1%4,864

Who reported

Physician35.7%5,973

Pharmacist6%1,005

Other health professional39.3%6,585

Lawyer0%8

Consumer or non-health professional6.2%1,039

Not given12.7%2,126

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 Folate analog reports

Which drugs are in the Folate analog class on this site?

Leucovorin calcium, Calcium folinate and Levoleucovorin calcium. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

16,736 reports through June 2026, 1,416 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?

diarrhoea (10.1%), neutropenia (7.3%), nausea (7.3%), vomiting (6.3%) and pyrexia (5.1%).

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.