Indications
Trifluridine is an antiviral and anticancer medicine available in two very different forms. As eye drops, it treats eye infections caused by the herpes simplex virus, such as herpes keratitis (infection of the clear front of the eye). As tablets, it is combined with Tipiracil to treat certain advanced cancers, mainly colorectal (bowel) cancer and stomach cancer, usually after other treatments have been tried.
How It Works
Trifluridine is similar to one of the building blocks of DNA. It is taken into the DNA of the virus or of cancer cells and stops them copying themselves properly, so the virus or tumour cannot keep growing. In the tablet form, Tipiracil prevents the body breaking down Trifluridine too quickly, so enough of it stays in the blood.
Dosage and Administration
Eye drops: use exactly as prescribed by an eye specialist. Treatment is usually frequent drops during the day at first, then fewer drops, and it is normally not continued for more than about 21 days because of the risk of eye damage.
Tablets (with Tipiracil): this is cancer treatment. The dose is calculated from body size and given in cycles with rest days, exactly as prescribed by the cancer specialist. Take within one hour after the morning and evening meals. Do not change the dose yourself.
Interactions
Eye drops have few known interactions; leave at least 5 minutes between different eye drops. Tablets may interact with other medicines that affect DNA or are handled like Thymidine, and with live vaccines, which should be avoided during treatment. Tell your doctor about all medicines, including herbal products.
Contraindications
Do not use if you are allergic to Trifluridine, Tipiracil or any ingredient. The tablets should not be used in pregnancy, and are not suitable for people with severe liver problems unless the specialist decides otherwise.
Side Effects
Eye drops: burning or stinging, swelling of the eyelids, irritation and, with long use, damage to the surface of the eye.
Tablets: low blood counts (especially low white cells, which raise infection risk), anaemia, low platelets, tiredness, nausea, vomiting, diarrhoea, poor appetite and hair thinning. Regular blood tests are needed.
Get urgent medical help if you have fever or chills, signs of infection, unusual bleeding or bruising, severe diarrhoea or vomiting, worsening eye pain or loss of vision, or signs of a severe allergic reaction.
Pregnancy and Lactation
The tablets can harm an unborn baby. Women and men should use reliable contraception during treatment and for some months after, as advised by the specialist. Do not breastfeed during treatment with the tablets. Eye drops should be used in pregnancy or breastfeeding only if the doctor decides the benefit outweighs the risk.
Precautions and Warnings
Do not use eye drops longer than prescribed. See your eye doctor if there is no improvement within about a week. Tablet treatment needs blood counts checked before each cycle; kidney and liver problems may need dose changes. Avoid contact with people who have infections where possible.
Overdose
Too many eye drops are unlikely to cause serious harm but may irritate the eye. An overdose of the tablets may cause severe lowering of blood counts and stomach upset; contact a doctor or hospital immediately.
Therapeutic Class
Antiviral (ophthalmic) and antineoplastic (nucleoside analogue, with Tipiracil in tablet form).
Storage
Eye drops: store in a refrigerator at 2 to 8°C, do not freeze, and keep tightly closed. Tablets: store below 30°C in a dry place, away from light. Keep all forms out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.