Valtrex

Before taking this medicine

Do not take Valtrex if you have had a clinically significant allergic reaction to valacyclovir, acyclovir or any of its ingredients, including anaphylaxis or a severe skin reaction. Use requires caution in older adults, people with kidney disease, those who are inadequately hydrated, and those taking other medicines that can harm the kidneys. Acute kidney failure can occur. People with reduced kidney function may need their treatment adjusted by the prescriber. Agitation, hallucinations, confusion and other brain-related effects can occur in adults and children, with or without kidney problems. Older adults are more likely to experience these effects. Serious blood disorders called thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) have occurred in clinical trials involving people with advanced HIV-1 disease, donor bone marrow transplants or kidney transplants. Treatment must be stopped if symptoms and laboratory findings indicate TTP/HUS. Stop Valtrex immediately and seek medical attention if you develop a painful rash involving areas such as the mouth or eyes, or a severe rash that is worsening. Severe skin reactions have been reported.