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Leucovorin Side Effects

The most commonly reported side effects of leucovorin include diarrhoea, nausea, and off label use, based on 18,907 FDA adverse event reports from 2004 to 2025. 3.4% of reports found the drug to be ineffective.

Leucovorin side effects

Percentages show how often each reaction appears relative to total reports for leucovorin.

1
Diarrhoea5.6%1,063
2
Nausea4.9%919
3
Off Label Use4.7%881
4
Diarrhoea3.7%709
5
Fatigue3.6%688
6
Drug Ineffective3.4%645
7
Neutropenia3.4%641
8
Vomiting3.2%614
9
Pyrexia3.2%599
10
Disease Progression3.0%565
11
Vomiting2.7%505
12
Neuropathy Peripheral2.6%492
13
Neutropenia2.5%471
14
Nausea2.4%454
15
Asthenia2.2%420

These are voluntary reports and do not establish that leucovorin caused these reactions.

Report severity

90.6%Serious17,128 reports
48.3%Hospitalizations9,134 reports
13.6%Fatal2,572 reports

Seriousness is determined by the reporter, not by OpenClaim.

Leucovorin drug interactions

Other drugs that appear in adverse event reports alongside leucovorin. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Fluorouracil50.5%9,542
2
Oxaliplatin40.5%7,650
3
Bevacizumab20.7%3,915
4
Irinotecan-hydrochloride20.0%3,783
5
Methotrexate9.3%1,761
6
Cetuximab5.4%1,017
7
Cyclophosphamide4.8%914
8
Dexamethasone4.6%866
9
Vincristine-sulfate4.4%823
10
Rituximab4.1%768
11
Prednisone3.9%745
12
Panitumumab3.8%718
13
Doxorubicin-hydrochloride3.4%651
14
Cytarabine3.3%619
15
Capecitabine3.2%608

Taken alongside

1
Fluorouracil13.1%2,469
2
Dexamethasone8.5%1,601
3
Acetaminophen8.2%1,543
4
Methotrexate7.3%1,372
5
Oxaliplatin7.2%1,353
6
Ondansetron6.8%1,283
7
Acyclovir6.4%1,206
8
Sulfamethoxazole5.4%1,030
9
Trimethoprim5.3%1,000
10
Irinotecan-hydrochloride5.2%981
11
Omeprazole4.9%919
12
Prednisone4.7%881
13
Pantoprazole-sodium4.5%845
14
Levothyroxine-sodium3.5%668
15
Aspirin3.5%659

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports leucovorin side effects

39.9% of leucovorin adverse event reports involve female patients and 47.6% involve male patients. The largest age group is adult at 56%. These figures reflect who reports side effects, not underlying risk.

Sex

Female39.9%
Male47.6%
Unknown12.5%

Age group

< 20.8%
2–112.1%
12–171.6%
18–6456.3%
65+39.1%

What is leucovorin used for

Conditions and purposes for which patients were taking leucovorin when the adverse event was reported.

Abdominal DiscomfortAcute Kidney InjuryAcute Lymphocytic LeukaemiaAcute Promyelocytic LeukaemiaAdenocarcinomaAdenocarcinoma GastricAdenocarcinoma MetastaticAdenocarcinoma Of AppendixAdenocarcinoma Of ColonAdenocarcinoma PancreasAdenosquamous Cell CarcinomaAdjuvant TherapyAdverse Drug ReactionAdverse ReactionAlopecia

Showing 15 of 631 indications

Leucovorin brand names and reporting trend

Leucovorin is sold under the brand name Leucovorin Calcium Preservative Free.

Brand names

Leucovorin Calcium Preservative Free21,996

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking leucovorin with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.