Pronunciation:

ay-SYE-kloe-vir

Brand Names:

• Zovirax
• Acyclovir

Dosage Forms:

• Ointment
• Cream

Classifications:

Therapeutic—

Antiviral

Pharmacologic—

Viral DNA Polymerase Inhibitor

Chemical—

Guanosine Nucleoside Analog

Uses of This Medicine:

Acyclovir belongs to the family of medicines called antivirals. Antivirals are used to treat infections caused by viruses. Usually they work for only one kind or group of virus infections.

Topical acyclovir is used to treat the symptoms of herpes simplex virus infections of the skin, mucous membranes, and genitals (sex organs). Although topical acyclovir will not cure herpes simplex, it may help relieve the pain and discomfort and may help the sores (if any) heal faster. Topical acyclovir may also be used for other conditions as determined by your doctor.

Acyclovir is available only with your doctor's prescription.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of topical acyclovir in children with use in other age groups.

Older adults—

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing the use of topical acyclovir in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Breast-feeding—

Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Fezolinetant

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Bupropion
• Dichlorphenamide
• Emtricitabine
• Fexinidazole
• Foscarnet
• Hydroxychloroquine
• Leflunomide
• Mycophenolate Mofetil
• Nitisinone
• Tenofovir Alafenamide
• Teriflunomide
• Tizanidine
• Vadadustat
• Warfarin

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Fosphenytoin
• Phenytoin
• Valproic Acid

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems—

Tell your doctor if your herpes simplex infection keeps coming back while you are using acyclovir.

Proper Use of This Medicine:

Acyclovir may come with patient information about herpes simplex infections. Read this information carefully. If you have any questions, check with your health care professional.

Do not use this medicine in the eyes.

Acyclovir is best used as soon as possible after the signs and symptoms of herpes infection (for example, pain, burning, or blisters) begin to appear.

Use a finger cot or rubber glove when applying this medicine. This will help keep you from spreading the infection to other areas of your body and will prevent the transmission of the infection to other persons . Apply enough medicine to completely cover all the sores (blisters). A 1.25-centimeter (approximately ½-inch) strip of ointment applied to each area of the affected skin measuring 5 × 5 centimeters (approximately 2 × 2 inches) is usually enough, unless otherwise directed by your doctor.

To help clear up your herpes infection, continue using acyclovir for the full time of treatment, even if your symptoms begin to clear up after a few days. Do not miss any doses. However, do not use this medicine more often or for a longer time than your doctor ordered.

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For topical dosage form (cream):
  • For herpes simplex infection:
    • Adults—Apply to the affected area(s), four to six times a day, for up to ten days.
    • Children—Use and dose must be determined by your doctor.
• For topical dosage form (ointment):
  • For herpes simplex infection:
    • Adults—Apply to the affected area(s), every three hours, for a total of six times a day, for seven days.
    • Children—Use and dose must be determined by your doctor.
    • Adults—Apply to the affected area(s), four to six times a day, for up to ten days.
    • Children—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, apply it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.

Storage—

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using This Medicine:

Women with genital herpes may be more likely to get cancer of the cervix (opening to the womb). Therefore, it is very important that Pap tests be taken at least once a year to check for cancer. Cervical cancer can be cured if found and treated early.

If your symptoms do not improve within 1 week, or if they become worse, check with your doctor.

Consider the possibility of viral resistance to acyclovir if little or no improvement in symptoms during therapy.

The areas affected by herpes should be kept as clean and dry as possible. Also, wear loose-fitting clothing to avoid irritating the sores (blisters).

Herpes infection of the genitals can be caught from or spread to your partner during any sexual activity. Although you may get herpes even though your sexual partner has no symptoms, the infection is more likely to be spread if sores are present. This is true until the sores are completely healed and the scabs have fallen off. The use of a condom (prophylactic) may help prevent the spread of herpes. However, spermicidal (sperm-killing) jelly or a diaphragm will not help prevent the spread of herpes. Therefore, it is best to avoid any sexual activity if either you or your partner has any symptoms of herpes. It is also important to remember that acyclovir will not keep you from spreading herpes to others.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Mild pain, burning, or stinging

Less common

Itching

Rare

Itching, stinging, or redness of the genital area

skin rash

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.