Valtrex (valacyclovir)

Overview of drug


 

How does valacyclovir work?

 

Valacyclovir is antiviral. 



 

What is the dose of valacyclovir?

Herpes simplex virus, mucocutaneous infection:


Genital:


Patients who are immunocompetent:


Treatment, initial episode: Oral: 1 g twice daily for 7 to 10 days; extend duration if lesion has not healed completely after 10 days (Ref).


Treatment, recurrent episode: Oral: 500 mg twice daily for 3 days or 1 g once daily for 5 days. Note: Treatment is most effective when initiated during the prodrome or within 1 day of lesion onset .


Suppressive therapy (eg, for severe and/or frequent recurrences): Oral: 500 mg or 1 g once daily. Note: Reassess need periodically (eg, annually). The 500 mg daily dose may be less effective in patients who experience very frequent (≥10) recurrences per year.




 

What are the side effects of valacyclovir?

As a prodrug of acyclovir, valacyclovir may also cause acute kidney injury (Ref). Like acyclovir, this may result most often from obstructive nephropathy but may also be due to interstitial nephritis or renal tubular necrosis. Kidney injury is reversible in most cases after dosage reduction or discontinuation; however, some cases may not return to baseline.

 

[1] Valacyclovir: Drug information. Uptodate Lexidrug. 


Mohammadi O, Kassim TA. Azathioprine. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542190/
Mohammadi O, Kassim TA. Azathioprine. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542190/
Mohammadi O, Kassim TA. Azathioprine. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542190/