What is LONSURF used for?

LONSURF is used to treat adults with metastatic colorectal cancer or metastatic gastric/gastroesophageal junction cancer that has already been treated with other therapies.

How should I take LONSURF?

You should swallow LONSURF tablets whole with food, twice a day on specific days of your 28-day cycle.

What should I do if I vomit after taking LONSURF?

Do not take another dose if you vomit or miss a dose; just continue with your next scheduled dose.

Can LONSURF cause low blood counts?

Yes, LONSURF can cause severe or life-threatening drops in white blood cells, red blood cells, and platelets.

Is LONSURF safe to take while pregnant?

No, LONSURF can cause serious harm or death to a fetus, and women of reproductive age should use effective contraception.

What are the common side effects of LONSURF?

Common side effects include fatigue, nausea, diarrhea, vomiting, abdominal pain, and decreased appetite.

Who should handle my LONSURF medication?

Anyone else handling the medication should wear gloves because it is a cytotoxic drug.

Does LONSURF affect older adults differently?

Older patients (65+) may have a higher risk of experiencing severe low blood cell counts while taking LONSURF.

tipiracil | CAS 183204-74-2 | QQHMKNYGKVVGCZ

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Antineoplastic (Cancer treatment)

LONSURF is a combination medicine containing trifluridine and tipiracil. It is used to treat certain types of advanced cancer in adults, specifically metastatic colorectal cancer and metastatic gastric or gastroesophageal junction adenocarcinoma, after other treatments have been tried.

How it worksLONSURF works by combining a substance that stops cancer cell DNA production (trifluridine) with a substance that prevents the body from breaking that medicine down (tipiracil), allowing the medicine to stay in the system longer to fight cancer.

Brand names:LONSURF

Used for

Metastatic colorectal cancer (used alone or with bevacizumab)Metastatic gastric or gastroesophageal junction adenocarcinoma

Conditions

Metastatic colorectal cancerMetastatic gastric cancerGastroesophageal junction adenocarcinoma

Class

ChemotherapyAntineoplasticAntineoplastic (Cancer treatment)Digestive systemHematologic system

How to take

FormsOral tablets

RoutesOral

The standard dose is 35 mg/m² taken orally twice daily with food. This is taken on days 1 through 5 and days 8 through 12 of a 28-day cycle.

Swallow tablets whole. Do not retake a dose if you vomit or miss a dose; simply continue with your next scheduled dose. The dose may be adjusted by a doctor based on body surface area.

Missed dose: Do not retake doses of LONSURF that are vomited or missed; continue with the next scheduled dose.

Key warnings

·Severe Myelosuppression: LONSURF can cause life-threatening drops in blood cell counts. Regular blood tests are required.
·Embryo-Fetal Toxicity: This drug can cause harm to an unborn baby. Women of reproductive age should use effective birth control while taking this medicine.

Side effects

Common

Low white blood cell count (neutropenia)Anemia (low red blood cell count)Low platelet count (thrombocytopenia)FatigueNauseaDecreased appetiteDiarrheaVomitingAbdominal painFever

Serious

·Severe myelosuppression (dangerously low blood cell counts)
·Infections due to low white blood cells (febrile neutropenia)
·Fetal harm if taken during pregnancy

Seek help if

·Signs or symptoms of infection
·Severe or persistent nausea, vomiting, diarrhea, or abdominal pain

Interactions

FoodTake LONSURF with food.

Special populations

PregnancyLONSURF can cause fetal harm and death. Animal studies have shown structural birth defects and decreased fetal weight. There is no data on use in pregnant women, so the risk should be carefully weighed.

PediatricThe safety and effectiveness of LONSURF in children have not been established.

GeriatricIn clinical studies, older patients (65+) taking LONSURF alone had higher rates of low white blood cells, anemia, and low platelets compared to younger patients.

Talk to your doctor

Monitor

·Complete blood counts (CBC)
·Signs of infection
·Gastrointestinal symptoms (nausea, vomiting, diarrhea, pain)

Questions to ask

·What are my blood counts looking like?
·How should I manage nausea or diarrhea while on LONSURF?
·What precautions should I take if I am planning a pregnancy?
·Should I use gloves when handling my medication?

Practical

DisposalFollow applicable special handling and disposal procedures for cytotoxic drugs.

Educational summary derived from FDA labeling, AI-assisted. Not medical advice — consult a healthcare professional. Updated 2026-04-26.