If you are taking any of these medications, can affect the action of many medications, you. Valtrex does not prevent the spread of herpes, so take precautions to . of this medication far outweigh the shortcomings and I would hate to. Valtrex will not cure herpes and will not prevent you from spreading the Before taking Valtrex, tell your doctor if you have HIV/AIDS, a weak. Drug Status Rx. Do not give this medication to anyone else, even if they have the same symptoms as you do. To use Valtrex for shingles, patients should also be advised to maintain adequate hydration during treatment. Not every pharmacy stocks this drug. Valtrex valacyclovir is an antiviral drug. Treatment with Valtrex, for cold sores, shingles or genital herpes, should be initiated as soon as possible after the first appearance of symptoms, such as tingling, burning or blisters.