You must tell your physician if you are allergic to
valacyclovir or
acyclovir. any kidney disease, blood disorders, immune deficiencies, dizziness etc. side effects associated are nausea, vomiting, fatigue, sore throat, hemolytic uremic syndrome etc.
You need to be concerned about the cumulative side effects of the two drugs. Otherwise, there are no serious interactions documented in the medical literature. Hope this helps. Take care.