What the label lists and what reports show
Tipiracil and trifluridine side effects
Tipiracil and trifluridine's FDA label: “The most common adverse reactions or laboratory abnormalities for single agent LONSURF (≥10%) are neutropenia, anemia, thrombocytopenia, fatigue, nausea, decreased appetite, diarrhea, vomiting, abdominal pain, and pyrexia.” FAERS holds 10,666 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fatigue (1,403 reports).
- No generic listed
Check it at the source: the tipiracil and trifluridine FDA label on DailyMed (effective November 5, 2025, Taiho Pharmaceutical Co., Ltd.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of LONSURF?LONSURF may cause serious side effects, including: See “ What is the most important information I should know about LONSURF? ” The most common side effects of LONSURF when used alone include: low blood counts tiredness and weakness nausea decreased appetite diarrhea vomiting stomach-area (abdominal) pain fever The most common side effects of LONSURF when used in combination with bevacizumab include: low blood counts tiredness and weakness nausea certain abnormal liver function blood tests decreased salt (sodium) in your blood diarrhea stomach-area (abdominal) pain decreased appetite Tell your healthcare provider if you have nausea, vomiting, or diarrhea that is severe or that does not go away. These are not all of the possible side effects of LONSURF. For more information, ask your healthcare provider. Call your doctor for medical advice about side effects. […]
Source: FDA drug label, Taiho Pharmaceutical Co., Ltd., effective November 5, 2025 (SPL set f5beed22-d71d-4c0d-8dca-2c7317d65d85), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions or laboratory abnormalities for single agent LONSURF (≥10%) are neutropenia, anemia, thrombocytopenia, fatigue, nausea, decreased appetite, diarrhea, vomiting, abdominal pain, and pyrexia.
Table 5: Adverse Reactions (≥5%) in SUNLIGHT
| Reaction | All Grades | Grade 3 or 4 | All Grades | Grade 3 or 4 |
|---|---|---|---|---|
| Nausea | 37 | 1.6 | 27 | 1.6 |
| Diarrhea Represents a composite of multiple related terms | 21 | 1.2 | 19 | 2.4 |
| Abdominal pain | 20 | 2.8 | 18 | 3.7 |
| Vomiting | 19 | 0.8 | 15 | 1.6 |
| Stomatitis | 13 | <0.4 | 4.1 | 0 |
| Constipation | 11 | 0 | 11 | 0.8 |
| Fatigue | 45 | 5 | 37 | 8 |
| Pyrexia | 4.9 | 0 | 6 | 0.4 |
| Infections and infestations | 31 | 8 | 24 | 8 |
| Decreased appetite | 20 | <0.8 | 15 | 1.2 |
| Musculoskeletal pain | 18 | 1.2 | 11 | 2 |
| Headache | 8 | 0 | 3.7 | 0 |
| Hypertension | 11 | 6 | 2 | 1.2 |
| Hemorrhage | 10 | 1.2 | 3.7 | 0.8 |
| Proteinuria | 6 | 0.8 | 1.2 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are described elsewhere in the labeling: Severe Myelosuppression [see Warnings and Precautions (5.1) ] The most common adverse reactions or laboratory abnormalities for single agent LONSURF (≥10%) are neutropenia, anemia, thrombocytopenia, fatigue, nausea, decreased appetite, diarrhea, vomiting, abdominal pain, and pyrexia. ( 6.1 ) The most common adverse reactions or laboratory abnormalities for LONSURF in combination with bevacizumab (≥20%) are neutropenia, anemia, thrombocytopenia, fatigue, nausea, increased AST, increased ALT, increased alkaline phosphatase, decreased sodium, diarrhea, abdominal pain, and decreased appetite. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Taiho Oncology, Inc. at 1-844-878-2446 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. …
Source: FDA drug label, Taiho Pharmaceutical Co., Ltd., effective November 5, 2025 (SPL set f5beed22-d71d-4c0d-8dca-2c7317d65d85), via openFDA; the full label on DailyMed
What do FAERS reports show?
10,666 reports list tipiracil and trifluridine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 4,219 are coded as a death and 2,932 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 20 reactions below, 11 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Tipiracil and trifluridine: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions