Precautions  

Before using acyclovir,

• tell your doctor and pharmacist if you are allergic to acyclovir, valacyclovir (Valtrex), or any other medications.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: amphotericin B (Fungizone); aminoglycoside antibiotics such as amikacin (Amikin), gentamicin (Garamycin), kanamycin (Kantrex), neomycin (Nes-RX, Neo-Fradin), paramomycin (Humatin), streptomycin, and tobramycin (Tobi, Nebcin); aspirin and other nonsteroidal anti-inflammatory medications such as ibuprofen (Advil, Motrin), and naproxen (Aleve, Naprosyn); cyclosporine (Neoral, Sandimmune); interferon; medications to treat HIV or AIDS such as zidovudine (Retrovir); methotrexate, pentamidine (NebuPent?); probenecid (Benemid); sulfonamides such as sulfamethoxazole and trimethoprin (Bactrim); tacrolimus (Prograf); and vancomycin (Vancocin). Many other medications may also interact with acyclovir, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if there is a possibility that you may be dehydrated from a recent illness or activity, or if you have or have ever had problems with your immune system; human immunodeficiency virus infection (HIV); acquired immunodeficiency syndrome (AIDS); or kidney, liver, or nervous system disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking acyclovir, call your doctor.
• if you are using acyclovir to treat genital herpes, you should know that genital herpes can be spread through sexual contact even if you don't have blisters or other symptoms and possibly even if you are using acyclovir. Talk to your doctor about ways to stop the spread of genital herpes and about whether your partner(s) should receive treatment.
• be sure to drink plenty of fluids during your treatment with acyclovir.

Administering your medication  

Before you use acyclovir, look at the solution closely. It should be clear and free of floating material. Gently squeeze the bag or observe the solution container to make sure there are no leaks. Do not use the solution if it is discolored, if it contains particles, or if the bag or container leaks. Use a new solution, but show the damaged one to your health care provider.

It is important that you use your medication exactly as directed. Do not stop your therapy on your own or skip doses for any reason because your infection could worsen and result in hospitalization or could become more difficult to treat. Do not change your dosing schedule without talking to your health care provider. Your health care provider may tell you to stop your infusion if you have a mechanical problem (such as a blockage in the tubing, needle, or catheter). If you have to stop an infusion, call your health care provider immediately so your therapy can continue.