{"entity":{"id":"valaciclovir","kind":"drug","name":"Valaciclovir","aka":["valacyclovir"],"tldr":"Valaciclovir is an antiviral tablet against herpes viruses. People having some cancer treatments take it, or aciclovir, to prevent cold sores, mouth ulcers and shingles coming back.","summary":"The Valtrex label covers cold sores, genital herpes and herpes zoster in adults and cold sores and chickenpox in children, and states that efficacy and safety have not been established in immunocompromised patients other than for suppressing genital herpes in HIV. AGIHO 2022 notes that valaciclovir \"has been shown to be non-inferior to acyclovir in preventing HSV stomatitis in patients with acute leukaemia and intensive chemotherapy\"; it recommends oral aciclovir as prophylaxis of oral HSV disease and says oral valaciclovir \"can be used alternatively (BI)\", the best regimen not yet defined. The NDA was first approved on 23 June 1995.","status":"approved","asOf":"2026-11-11","wikipedia":"https://en.wikipedia.org/wiki/Valaciclovir","links":[{"label":"US label (DailyMed): Valtrex","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=56a62c21-bead-4f3b-a24e-c3fd0b4a732f"},{"label":"Sandherr et al., Management of herpesvirus reactivations in patients with solid tumours and hematologic malignancies: AGIHO guideline update (Ann Hematol 2022)","url":"https://doi.org/10.1007/s00277-021-04746-y"}],"tags":["supportive","generic","supportive-care-gaps-2026-11"],"related":["posaconazole"],"cancers":[],"sections":[],"technologies":["allogeneic-hsct"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"provenance":{"editedBy":"OnCo supportive care gap fill (DailyMed, openFDA, Drugs@FDA, emc SmPCs, NICE, ESMO, ASCO, MASCC, SITC, ASTCT, ITAC, Europe PMC)","editedOn":"2026-11-11"},"brand":"Valtrex","modality":"Antiviral (oral prodrug of aciclovir)","supportive":true,"mechanism":"A prodrug of aciclovir, a deoxynucleoside analogue that inhibits herpesvirus DNA polymerase; better absorbed by mouth than aciclovir.","approvals":[{"region":"US","year":1995,"indication":"Cold sores, genital herpes and herpes zoster in adults; cold sores and chickenpox in children","note":"Year is the Valtrex NDA 020487 approval (Drugs@FDA); prophylaxis during cancer treatment is off-label"}],"mechanismSteps":[],"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/valaciclovir/","neighbours":{"drug":[{"id":"posaconazole","kind":"drug","name":"Posaconazole","route":"/drugs/posaconazole/"}],"technology":[{"id":"allogeneic-hsct","kind":"technology","name":"Allogeneic stem cell transplantation","route":"/technologies/allogeneic-hsct/"}],"term":[{"id":"lymphoma-tx-pjp-and-infection-prophylaxis","kind":"term","name":"Infection prophylaxis in lymphoma: PJP, herpes, fungal risk and vaccination","route":"/terms/lymphoma-tx-pjp-and-infection-prophylaxis/"}]}}