Skip to content

Valaciclovir

Valaciclovir is an antiviral medicine taken by mouth as a film-coated tablet. It is used for several infections caused by herpes viruses, including shingles and genital herpes. In the body it changes quickly into aciclovir, the compound that acts against the virus. Treatment can shorten an outbreak and ease its symptoms, but it does not clear the virus from the body.

Medicine containing Valaciclovir

Valtrex

Herpes Zoster, Herpes Simplex, Genital Herpes

500 · 1000mg

Valtrex tablets contain valaciclovir for herpes zoster, herpes simplex and genital herpes. Valaciclovir is a prodrug converted to aciclovir. Several strengths are supplied, pack sizes are shown. You see the price per tablet for each option.

FromUS$2.55/ tabletView

Key points

  • Valaciclovir is a prodrug of aciclovir and is converted rapidly after each dose.
  • Tablets are supplied as Valtrex in 500 mg and 1000 mg strengths.
  • Antiviral effect begins within about 1 to 2 hours and lasts roughly 8 to 12 hours.

What valaciclovir is used for

It is used to treat shingles in adults, and herpes simplex infections of the skin and genital herpes in adults and adolescents over 12. Cold sores are also treated with it, and it can be taken to help prevent these infections from returning. Further uses are HSV infections of the eye and prevention of cytomegalovirus infection after an organ transplant. It belongs to the antivirals group; the pages on herpes zoster, herpes simplex and genital herpes describe the infections it treats.

How it works

Valaciclovir is inactive as supplied and is converted rapidly to aciclovir in the body. Aciclovir selectively inhibits viral DNA polymerase, the enzyme the virus needs to copy its genetic material. Blocking that step interrupts DNA synthesis in herpes viruses, so new virus particles are not produced and the immune system has a better chance of controlling the infection.

Forms and brands

Valaciclovir comes as Valtrex film-coated tablets in 500 mg and 1000 mg strengths, swallowed with an adequate amount of fluid. Prices are shown in ringgit. Orders are prepared by pharmacy partners in India and shipped to Malaysia in discreet packaging.

Safety

Do not take valaciclovir if you are allergic to valaciclovir, aciclovir or any other ingredient in the tablet, or if you have previously developed DRESS after taking it. Fluid intake should be adequate, and the medicine is used with caution in elderly patients; kidney impairment and older age both call for a dose adjustment.

Headache and nausea are minor effects, while dizziness and abdominal pain may also occur. Renal impairment and neurological symptoms are serious and need immediate medical attention. A rash with fever and enlarged lymph nodes can be the start of DRESS: stop the tablets and contact a doctor or seek medical attention at once. Take care with other medicines that are nephrotoxic. In pregnancy, use only if clearly needed; while breastfeeding, use with caution and monitor the infant.

What the sources say

  • Valaciclovir is one of the medicines called antivirals, and works by killing or stopping the growth of herpes simplex, varicella zoster and cytomegalovirus (PIL).
  • It treats and controls outbreaks of genital herpes but will not cure the infection, and should be used alongside safe sexual practices (MedlinePlus).
  • DRESS has been reported with valaciclovir; it starts as flu-like symptoms and a facial rash, then extends with high body temperature, raised liver enzymes, eosinophilia and enlarged lymph nodes (PIL).

Further reading

Last updated