This page contains brief details about the drug , it's indication, dosage & administaration, mechanism of action, related brands with strength, warnings and common side effects.

Background and Date of Approval

The U.S. FDA-approved Valacyclovir to treat people with shingles and herpes infections of the skin, eyes, and genitals, cytomegalovirus in organ transplant patients, prevent infection relapse, prevent cold sores on June 25, 2001.

Mechanism of Action of undefined

Valacyclovir is a prodrug that gets converted into a substance called acyclovir. Acyclovir blocks an important enzyme that the virus needs for replication. By restricting the replication of the virus, Valacyclovir helps to control and reduce the symptoms of herpes, such as painful sores or blisters.

Uses of undefined

Valacyclovir is used to treat shingles and herpes infections of the skin, eyes, and genitals, cytomegalovirus in organ transplant patients, prevent infection relapse, and prevent cold sores.  Herpes virus is associated with causing a cold sore that produces painful ulcers around the mouth. Shingles infection causes blisters over the skin. Cytomegalovirus infection causes flu-like symptoms along with skin rashes and swollen lymph glands

undefined Drug administaration and Dosage available

Take the Valacyclovir tablet as your physician advises. Do not crush, chew, or open the medicine. Your physician will decide the correct dosage and duration based on age, body weight, and disease condition. Only stop taking the tablet if your doctor advises you to stop

Warnings, Precautions and Side Effects of undefined


Do not consume Valcivir 1000mg tablet if you are allergic to Acyclovir or Valacyclovir and its other ingredients. Before starting the treatment, inform your physician if you have a liver or kidney condition because dose adjustment is needed in such a condition. Notify your doctor if you are above the age of 65 years or with weakened immune system. 


Do not continue taking Valacyclovir if you experience any rashes with fever, inflammation of lymph nodes, higher levels of liver enzymes, and eosinophilia (increased WBC count). While taking this tablet daily, it is advised to have safe sex to prevent the spread of genital herpes infection to your partner. Kidney patients should cautiously get injected with Valacyclovir.

Side Effects

The most common side effects of Valacyclovir are sickness, dizziness, vomiting, diarrhea, photosensitivity (skin reaction after exposure to sunlight)

Serious side effects while taking Valacyclovir are swelling of the lips, face, neck, and throat, angioedema (difficulty in breathing), collapse in blood pressure, skin rashes (with or without blisters), or itchy edema dress (drug reaction with eosinophilia and systemic symptoms) syndrome fever, flu.

Word Of Advice

Keep Valacyclovir out of sight and reach of children. Do not store above 30°C. Do not freeze. Dose adjustments will be suggested to child and kidney patients. Do not take a double dose to make up for a forgotten dose. Consuming plenty of water or fluid throughout the day while on the treatment with tablets is advised to avoid side effects that affect the nervous system and kidneys. Discuss with your doctor if you have undergone organ transplantation before commencing the treatment with Valacyclovir is advised. Avoid having sex if you have genital sores or blisters.

Frequently Asked Question


  1. Goodman & Gilman’s, The Pharmacological Basis of Therapeutics, Antiviral agents (Nonretroviral), 12th edition, 2011, 1594.
  2. KD Tripathi, Essentials of Medical Pharmacology, Antiviral drugs, 7th edition, 2013, 799.
  3. Ranbaxy (UK) Limited, Electronic medicines compendium (emc), [ Revised on Nov 2022], [Accessed on 18th May 2023],


The drug information on this page is not a substitute for medical advice. It is meant for educational purposes only. For further details, consult your doctor about your medical condition to know if you are eligible to receive this treatment.