Acyclovir topical

Name: Acyclovir topical

What Is Acyclovir Topical?

Acyclovir topical (for the skin) is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection.

Acyclovir topical cream is used to treat cold sores.

Acyclovir topical ointment is used to treat genital herpes lesions.

Acyclovir topical will not cure or prevent herpes, but it can lessen the symptoms of the infection.

Acyclovir topical may also be used for purposes not listed in this medication guide.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

You should not use this medicine if you are allergic to acyclovir or valacyclovir (Valtrex).

To make sure acyclovir topical is safe for you, tell your doctor if you have:

  • weak immune system (caused by disease or by using certain medicine).

FDA pregnancy category B. Acyclovir topical is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Herpes virus can be passed from an infected mother to her baby during childbirth. If you have genital herpes, it is very important to prevent herpes lesions during your pregnancy so that you do not have a genital lesion when your baby is born.

It is not known whether acyclovir topical passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby. You should not breast-feed if you have a herpes lesion on or near your breast.

Acyclovir topical should not be used on a child younger than 12 years old.

Acyclovir Pharmacokinetics

Absorption

Bioavailability

Not appreciably absorbed into systemic circulation following topical application to intact skin.101 112

Not detected in blood or urine of immunocompromised adults following application of 5% ointment to intact skin (4.5 inch2) at a dosage of 25 mg (1-cm ribbon) 4 times daily for 7 days.101 112

Following topical application of 5% ointment in patients with localized varicella-zoster virus (VZV) infections, plasma acyclovir concentrations were ≤0.28 mcg/mL or ≤0.78 mcg/mL in those with normal or impaired renal function, respectively.101

Following repeated (5 times daily for 4 days) topical application of 5% cream to intact skin (710 cm2) in adult males, plasma acyclovir concentrations measured 1 hour after the final application were undetectable or just above the limits of detection.112

Systemic absorption of 5% cream not evaluated in children <18 years of age.112

Distribution

Not fully characterized following topical application.a

Crosses placenta following oral or IV administration.105 117

Not known if drug or its metabolites distributed into human milk following topical application.101 Following oral or IV administration, distributed into human milk in concentrations greater than concurrent maternal plasma concentrations.100 101 117

Elimination

Metabolism

Not fully characterized following topical application.a

Converted in vivo to the pharmacologically active triphosphate metabolite.101

Elimination Route

Following systemic absorption, excreted principally in urine.101

Following topical application of 5% ointment in immunocompromised patients with localized VZV infections, ≤9.4% of total daily dose excreted in urine.101

Following repeated (5 times daily for 4 days) topical application of 5% cream to intact skin (710 cm2) in adult males, 0.04% of the daily dose was detected in urine within 24 hours.112

Use Labeled Indications

Herpes virus:

Buccal tablet: Treatment of recurrent herpes labialis (cold sores) in immunocompetent adults.

Cream: Treatment of recurrent herpes labialis (cold sores) in immunocompetent children ≥12 years of age, adolescents, and adults.

Ointment: Management of initial genital herpes and in limited non-life-threatening mucocutaneous herpes simplex virus infections in immunocompromised patients.

Contraindications

Buccal tablet: Hypersensitivity to acyclovir, valacyclovir, milk protein concentrate or any component of the formulation

Cream, ointment: Hypersensitivity to acyclovir, valacyclovir, or any component of the formulation

Dosing Geriatric

Refer to adult dosing.

Storage

Buccal tablet: Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C and 30°C (59°F and 86°F). Protect from moisture.

Cream: Store at or below 25°C (77°F); excursions permitted between 15°C and 30°C (59°F and 86°F).

Ointment: Store at controlled room temperature of 20°C to 25°C (68°F to 77°F) in a dry place.

What should I avoid while using acyclovir topical?

Avoid getting this medication in your eyes, nose, or mouth. If this does happen, rinse with water. When treating a cold sore, apply the medication only the outer part of your lips.

Herpes infections are contagious and you can infect other people, even while you are being treated with acyclovir. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

Acyclovir will not prevent the spread of genital herpes. Avoid sexual intercourse or use a latex condom to prevent spreading the virus to others.

Acyclovir topical side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Common side effects may include:

  • dry, cracked, or peeling lips;

  • dryness or flaking of treated skin;

  • burning, stinging, or itching when the medicine is applied.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Pharmacology

Mechanism of Action

Exerts its antiviral effect on herpes simplex viruses and varicella zoster virus by interfering with DNA synthesis and inhibiting viral replication

Helps shed herpes virus quicker and reduces pain and duration; used for management of initial episodes of herpes genitalis and in mucocutaneous herpes simplex viral infections in immunocompromised patients

Absorption

Minimal

Metabolism

In cells infected with herpes viruses, principally by intracellular phosphorylation of drug by virus-coded thymidine kinase and several cellular enzymes

Elimination

Excretion: Urine

Side Effects

Dry/cracked lips, burning, stinging, or flaky skin may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she 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, seek immediate medical attention 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.

List Acyclovir Cream side effects by likelihood and severity.

Interactions

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.

Renal Dose Adjustments

No adjustment recommended.

Liver Dose Adjustments

No adjustment recommended.

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