Lonsurf Use In Pregnancy & Lactation

Women of childbearing potential/Contraception in males and females: Based on findings in animals, trifluridine may cause foetal harm when administered to pregnant women. Women should avoid becoming pregnant while taking Lonsurf and for up to 6 months after ending treatment. Therefore, women of child-bearing potential must use highly effective contraceptive measures while taking Lonsurf and for 6 months after stopping treatment. It is currently unknown whether Lonsurf may reduce the effectiveness of hormonal contraceptives, and therefore women using hormonal contraceptives should add a barrier contraceptive method.
Men with a partner of child-bearing potential must use effective contraception during treatment and for up to 6 months after discontinuation of treatment.
Pregnancy: There are no available data from the use of Lonsurf in pregnant women. Based on the mechanism of action, trifluridine is suspected to cause congenital malformations when administered during pregnancy. Studies in animals have shown reproductive toxicity (see Pharmacology: Toxicology: Preclinical safety data under Actions). Lonsurf should not be used during pregnancy unless the clinical condition of the woman requires treatment with Lonsurf.
Breast-feeding: It is unknown whether Lonsurf or its metabolites are excreted in human milk. Studies in animals have shown excretion of trifluridine, tipiracil hydrochloride and/or their metabolites in milk (see Pharmacology: Toxicology: Preclinical safety data under Actions). A risk to the suckling child cannot be excluded. Breast-feeding should be discontinued during treatment with Lonsurf.
Fertility: There are no data available on the effects of Lonsurf on human fertility. Results of animal studies did not indicate an effect of Lonsurf on male or female fertility (see Pharmacology: Toxicology: Preclinical safety data under Actions). Patients who wish to conceive a child should be advised to seek reproductive counselling and cryo-conservation of either the ovum or sperm prior to starting Lonsurf treatment.