Valacyclovir

💊 What is Valacyclovir used for?

• •Cold sores (herpes labialis) in adults and in children aged 12 and older
• •Treatment of the first (initial) episode of genital herpes in immunocompetent adults
• •Treatment of recurrent episodes of genital herpes in immunocompetent adults
• •Long-term suppressive therapy to reduce recurrent genital herpes in immunocompetent and HIV-1-infected adults
• •Reducing the transmission of genital herpes in immunocompetent adults
• •Herpes zoster (shingles) in adults
• •Chickenpox in children aged 2 to under 18

How it works

The label describes valacyclovir as a DNA polymerase inhibitor, a type of antiviral that works against the enzyme the virus uses to copy its genetic material. The label does not explain this in further detail.

How it is usually taken

• •The label says valacyclovir tablets may be taken with or without meals. Tablets are film-coated and are described as capsule-shaped. The label gives different schedules for each condition, and doses are usually spaced about 12 hours apart for some uses, such as cold sore treatment. The label says cold sore treatment should not last more than 1 day. Follow the exact instructions from your prescriber or pharmacist.

Comes as

• •500 mg tablets (blue, film-coated, capsule-shaped, unscored)
• •1 gram tablets (blue, film-coated, capsule-shaped, partially scored)
• •The label says a liquid (oral suspension) can be prepared by a pharmacy from the 500 mg tablets for children who cannot take a solid form.

⚠️ Valacyclovir side effects

🛑 Who should not take Valacyclovir, and who should be careful

The label says not to take it if

• 🚨You have had a clinically significant allergic (hypersensitivity) reaction, such as anaphylaxis, to valacyclovir, acyclovir, or any ingredient in the tablet.
• 🚨You have had a severe skin reaction (severe cutaneous adverse reaction) to valacyclovir or acyclovir.

Tell your doctor before taking it if

• •Tell your prescriber or pharmacist about your full medical history, including any kidney problems.
• •The label says to maintain adequate hydration (drinking enough fluids).
• •The label advises caution in older adults, and says dosage reduction is recommended for people with impaired kidney function.
• •The label says the safety and effectiveness of valacyclovir have not been established in immunocompromised patients, except for suppression of genital herpes in HIV-1-infected patients.

🔀 Valacyclovir with other medicines, food and alcohol

The label says to discuss these with your doctor or pharmacist

• •The label states that no clinically significant drug-drug or drug-food interactions are known.
• •The label advises caution when valacyclovir is used with other potentially nephrotoxic (kidney-affecting) drugs, because of the risk of acute renal failure.

Alcohol and food

The label says valacyclovir tablets may be taken without regard to meals. The label does not provide information about alcohol.

🤰 Valacyclovir in pregnancy and breastfeeding

Pregnancy

The label says clinical data over several decades have not identified a drug-associated risk of major birth defects with valacyclovir and its metabolite acyclovir. It notes there are insufficient data on miscarriage and other outcomes. The label also says untreated herpes simplex during pregnancy carries risks to the fetus. Discuss pregnancy with your prescriber.

Breastfeeding

The label does not say.

🗓️ Storage, missed doses and taking too much

Storage

Store at 20 to 25 degrees C (68 to 77 degrees F), as stated on the label.

If a dose is missed

The label says that if you miss a dose, take it as soon as you remember. Do not double your next dose or take more than the prescribed dose.

If too much is taken

The label says caution should be taken to prevent accidental overdose. It notes that acyclovir can build up in the kidney tubules if too much is taken, and that in cases of acute renal failure with no urine output, hemodialysis (a kidney filtering treatment) may be used. If you think you have taken too much, contact a doctor, pharmacist, or poison control center right away.

🗒️ Questions to ask about Valacyclovir

• What is the right way for me to take valacyclovir for my specific condition?
• When should I start treatment, based on the label's timing guidance for my condition?
• Should I drink extra fluids while I take this medicine, and how much?
• What signs of a serious skin reaction or kidney problem should I watch for?
• Are there other medicines I take that could affect my kidneys?
• How long should I continue suppressive therapy, and what should I do about safer sex practices?

❓ Valacyclovir: frequently asked questions