As with any medication, the use of valacyclovir can lead to some side effects. The side effects vary from patient to patient. Included below is a short summary and not a comprehensive list. These are not all the side effects of valacyclovir. For more information ask your healthcare provider or pharmacist.
- Kidney failure and nervous system problems are not common, but can be serious in some patients taking valacyclovir. Nervous system problems include aggressive behavior, unsteady movement, shaky movements, confusion, speech problems, hallucinations (seeing or hearing things that are really not there), seizures, and coma. Kidney failure and nervous system problems have happened in patients who already have kidney disease and in elderly patients whose kidneys do not work well due to age. Always tell your healthcare provider if you have kidney problems before taking valacyclovir. Call your doctor right away if you get a nervous system problem while you are taking valacyclovir.
- Common side effects of valacyclovir in adults include headache, nausea, stomach pain, vomiting, and dizziness. Side effects in HIV-1-infected adults include headache, tiredness, and rash. These side effects are usually mild and do not cause patients to stop taking valacyclovir.
- Other less common side effects in adults include painful periods in women, joint pain, depression, low blood cell counts, and changes in tests that measure how well the liver and kidneys work.
- The most common side effect seen in children aged less than 18 years was headache.
- Talk to your healthcare provider if you develop any side effects that concern you.