This medication is used to treat cold sores around the mouth (caused by herpes virus) that keep coming back.

Acyclovir is an antiviral drug. However, it is not a cure for the infection. The virus that causes infection continues to live in the body between outbreaks. Acyclovir makes outbreaks shorter and less severe. It helps the sores heal faster, keeps new sores from forming, and decreases pain/itching. This medication may also help reduce how long pain lasts after the sores heal.

Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start using acyclovir buccal tablets and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Apply one tablet within one hour after you have the first symptom of a cold sore, and before a cold sore appears. Symptoms may include itching, redness, burning, or tingling. Apply the tablet on the same side of your mouth as the cold sore symptoms.

Before applying the tablet, find the area in your mouth in which to place the tablet. It should be placed on the upper gum, just above the left or right incisor tooth. The incisors are the teeth just to the left and right of your two front teeth. With dry hands, remove one tablet from the blister pack and place it in your mouth with the round side facing against your gum and gently push it into place. Remove your hand from inside your mouth and gently press your finger on the outside of your upper lip for 30 seconds. This will make the tablet stick to your gum. The tablet will slowly dissolve over time and should be left in place. You may eat and drink while using this medication. Do not crush, chew, suck, or swallow the tablet.

If the tablet does not stick to your upper gum or falls off within the first 6 hours after you apply it, the same tablet should be placed back onto your upper gum right away. If it still does not stay in place, apply another acyclovir tablet to your upper gum.

If you accidentally swallow the tablet within the first 6 hours after placement, drink a glass of water and apply a new dose to your gum. However, if the tablet has been in place 6 hours or longer and it falls out or you swallow it, do not re-apply the tablet.

Avoid doing things that may keep the buccal tablet from sticking to your gum, including touching or pressing the tablet after placement, wearing an upper denture that interferes with tablet placement, chewing gum, and brushing your teeth while the tablet is in place. You may gently rinse your mouth with water to clean your teeth while the tablet is in place. Drink plenty of liquids if you have dry mouth.

This medication works best when started at the first sign of a cold sore, as directed by your doctor. It may not work as well if you delay treatment.

Tell your doctor if your condition does not get better or if it gets worse.

Headache or pain at the application site may occur. If either of these effects lasts or gets worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using acyclovir, tell your doctor or pharmacist if you are allergic to it; or to valacyclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Tell your health care professional that you are using acyclovir before having any immunizations/vaccinations (such as vaccines against the varicella virus).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this form of acyclovir passes into breast milk. However, this medication is unlikely to harm a nursing infant. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Acyclovir is very similar to valacyclovir. Do not use medications containing valacyclovir while using acyclovir.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor tells you to.

Not applicable.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.