Acyclovir belongs to a class of medications known as antivirals. It works by stopping the growth of the virus. This medication is used to treat cold sores/fever blisters. It can speed up healing of the sores and decrease symptoms (such as tingling, pain, burning, itching).
Side effects are:
•Dry/cracked lips.
•Burning.
•Stinging.
•Flaky skin.
•Swelling.