Cold sore drug shows no benefit for early Alzheimer's disease

Embargoed until: Publicly released: 2025-12-18 03:00

International

CC0, Story by Lyndal Byford, Australian Science Media Centre

A drug used to treat cold sores, which targets the herpes virus, has shown no benefit in treating people with early stage Alzheimer's disease, despite recent studies suggesting a link between the herpes virus and dementia. The trial found that the cognitive scores of those treated with the drug valacyclovir were worse than the scores of those taking a placebo. Herpes viruses remain dormant in nerve cells after an initial infection, and one theory of how Alzheimer's develops suggests that reactivation of these viruses could be a cause or a contributor to Alzheimer's disease. An accompanying editorial says it is now reasonable to assume that reactivated herpes simplex virus type 1 does not contribute to Alzheimer's disease symptoms.

News release

From: JAMA

Valacyclovir Treatment of Early Symptomatic Alzheimer Disease

JAMA
Original Investigation

About The Study: Valacyclovir, an antiviral medication, was not efficacious with cognitive worsening for the primary outcome and it is not recommended to treat individuals with early symptomatic Alzheimer disease and herpes simplex virus seropositivity.

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Research JAMA, Web page Please link to the article in online versions of your report (the URL will go live after the embargo ends).

Editorial / Opinion JAMA, Web page Please link to the article in online versions of your report (the URL will go live after the embargo ends).

Journal/
conference: JAMA

Research: Link to Paper 1 | Paper 2

Organisation/s: New York State Psychiatric Institute, USA

Funder: The study was supported by grant R01AG055422 from the National Institute on Aging.

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