Acyclovir: Uses & Side Effects (2024)

What is this medication?

ACYCLOVIR (ay SYE kloe veer) treats infections caused by viruses. This medication will not treat colds, the flu, or infections caused by bacteria.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Zovirax

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

• Kidney disease
• An unusual or allergic reaction to acyclovir, ganciclovir, valacyclovir, other medications, foods, dyes, or preservatives
• Pregnant or trying to get pregnant
• Breast-feeding

How should I use this medication?

Take this medication by mouth with a glass of water. Follow the directions on the prescription label. You can take it with or without food. Take your medication at regular intervals. Do not take your medication more often than directed. Take all of your medication as directed even if you think you are better. Do not skip doses or stop your medication early.

Talk to your care team regarding the use of this medication in children. While this medication may be prescribed for selected conditions, precautions do apply.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

Do not take this medication with any of the following:

• Cidofovir

This medication may also interact with the following:

• Adefovir
• Amphotericin B
• Certain antibiotics like amikacin, gentamicin, tobramycin, vancomycin
• Cimetidine
• Cisplatin
• Colistin
• Cyclosporine
• Foscarnet
• Lithium
• Methotrexate
• Probenecid
• Tacrolimus

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Tell your care team if your symptoms do not improve. This medication works best when started very early in the course of an infection. Begin treatment at the first signs of infection.

Drink 6 to 8 glasses of water or fluids every day while you are taking this medication. This will help prevent side effects.

You can still pass chickenpox, shingles, or herpes to another person even while you are taking this medication. Avoid contact with others as directed. Genital herpes is a sexually transmitted disease. Talk to your care team about how to stop the spread of infection.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

• Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
• Confusion
• Hallucinations
• Kidney injury—decrease in the amount of urine, swelling of the ankles, hands, or feet
• Seizures

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

• Diarrhea
• Headache
• Nausea
• Upset stomach
• Vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 15 and 25 degrees C (59 and 77 degrees F). Throw away any unused medication after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.