Herpes medication may have severe interactions result in
In a “Rote Hand brief” is warned of the potentially fatal interactions between Herpes-medications from the class of brivudin-containing medicines and so-called fluoro-pyrimidines. Not Brivudin and fluoro pyrimidines should therefore be taken at the same time.
Between the application of Brivudin and fluoro pyrimidines, a distance of at least four weeks must be observed in order to avoid potentially fatal interactions, warn the holder of the Authorisation brivudin-containing medicines in consultation with the European medicines Agency (EMA). A corresponding Red-Hand-letter was published on the website of the Federal Institute for drugs and medical products (BfArM).
Brivudin and fluoro-pyrimidines
Medicines with Brivudin are used against the viruses Herpes simplex type 1 (trigger cold sores) and Herpes Zoster (the trigger for the shingles). Fluoro-pyrimidines in turn in cancer therapy, but also in the treatment of fungal infections. Both substances are taken in parallel, this can have fatal consequences.
Fluoropyrimidine toxicity is greatly increased
Because Brivudin inhibits via its main metabolites bromovinyl uracil (BVU), the dihydropyrimidine dehydrogenase (DPD), an enzyme of the Pyrimidine metabolized to a-based drugs such as Fluorouracil, Capecitabine, Tegafur, and Flucytosine. Thus, the inhibition of DPD leads to an increased Level of fluoro-pyrimidines, what is the Fluoropyrimidine toxicity is increased such that it is potentially fatal.
The threat of deaths due to interactions
“Deaths can occur as a result of a Drug interaction between Brivudin and fluoro pyrimidines (e.g., Fluorouracil (5-FU), Capecitabine, Tegafur, Flucytosine)”, so the clear warning in the Red-Hand-letter. Therefore, the smpc, leaflet and labelling of the cartons to be revised accordingly, to promote compliance with, the 4-week interval between treatment with Brivudin and fluoro pyrimidines noted.
A patient card with the most important information for patients and health professionals each pack is to be attached and a check list for prescribing Doctors to be provided.
Who should not receive Brivudin?
Brivudin is according to the information of the Red-Hand-letter contraindicated in patients
- recently, a cancer chemotherapy have received, currently receive, or within four weeks to contain with medicines Fluorouracil, including topical preparations, its Prodrugs (e.g., Capecitabine, Tegafur) and combination products containing any of these active ingredients or other fluoro pyrimidines.
- recently an anti-fungal therapy with Flucytosine have received or currently receive; there is a small amount of Flucytosine is converted into Fluorouracil.
- are immunocompromised, such as those that have recently received a cancer chemotherapy.