What special precautions should I follow?  

Before using topical acyclovir,

• tell your doctor and pharmacist if you are allergic to acyclovir, valacyclovir (Valtrex), any other medications, or any of the ingredients in acyclovir cream or ointment. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had any condition that affects your immune system such as human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS).
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while using acyclovir, call your doctor.

What special dietary instructions should I follow?  

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?  

Apply the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not apply extra cream or ointment to make up for a missed dose.