During extensive clinical trials studying the side effects of valacyclovir, headaches were reported the most often. Other common side effects included nausea, abdominal pain, and dizziness. Some valacyclovir side effects should be reported immediately to your healthcare provider, including unexplained swelling, hallucinations, or difficulty swallowing. Rare side effects include diarrhea, hair loss, and kidney failure.
Valacyclovir Side Effects: An Introduction
As with any medicine, side effects are possible with
valacyclovir hydrochloride (
Valtrex®). However, not everyone who takes this drug will experience side effects. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor, meaning they require no treatment or are easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with valacyclovir. Your healthcare provider can discuss a more complete list of valacyclovir side effects with you.)
Serious Side Effects of Valacyclovir
Some valacyclovir side effects should be reported immediately to your healthcare provider. These include but are not limited to:
- Decreased urination
- Vision changes, including blurred or double vision
- Unexplained skin rash
- Unexplained blisters or peeling of the skin
- Itching
- Hives
- Unexplained swelling
- Wheezing
- Difficulty breathing or swallowing
- Unusual bleeding or bruising
- Unexplained fever
- Hallucinations
- Aggressive behavior
- Unsteady or shaky movements
- Confusion
- Speech problems
- Seizures
- Tremors.