According to Drugs.com, Valtrex is not known to interact with alcohol, making it safe to drink while under treatment. However, Valtrex can harm the kidneys and may interact with other medications that affect the kidneys.
Drugs.com warns that those who are allergic to valacyclovir or acyclovir (Zovirax) should not take Valtrex. Previous medical conditions, such as HIV/AIDS, kidney disease or having had a bone marrow transplant, can create complications when taking Valtrex; a doctor's consultation is necessary in these cases. Pregnant women can take Valtrex, but the child can still be infected with herpes during birth. Women who are breastfeeding should talk to their doctors before taking Valtrex.