Acyclovir topical

Herpes Labialis

Treatment of recurrent herpes labialis (perioral herpes, cold sores, fever blisters) in immunocompetent adults and children ≥12 years of age.111 112 114

Genital Herpes

Has been used for topical treatment of initial episodes of genital herpes in immunocompromised or immunocompetent adults.101 a

Topical antivirals generally not recommended for treatment of genital herpes.106 110 114 CDC and others recommend oral acyclovir, oral famciclovir, or oral valacyclovir as drugs of choice for treatment of initial episodes of genital herpes and for episodic treatment or chronic suppressive therapy of recurrent genital herpes.106 110 114

Has not been effective for prevention of recurrent genital herpes when initiated immediately following development of prodromal symptoms (e.g., itching, burning, tingling, numbness).107 109

No evidence that topical acyclovir prevents transmission of infection to other individuals.101

Mucocutaneous Herpes Simplex Virus (HSV) Infections

Has been used for topical treatment of non-life-threatening, nongenital, mucocutaneous HSV infections in immunocompromised adults;101 113 efficacy of such treatment not established in immunocompetent individuals.101 113

Systemic therapy (e.g., oral or IV acyclovir) usually recommended for treatment of mucocutaneous HSV infections.113 114

Should not be used for prevention of recurrent HSV infections.101 No evidence that topical acyclovir prevents transmission of HSV or prevents recurrent HSV infections when applied in the absence of signs and symptoms of infection.101

• Converted in vivo to the pharmacologically active triphosphate metabolite.101

• Exerts antiviral effect by interfering with DNA synthesis and inhibiting viral replication.101

• Active against various Herpesviridae,a including herpes simplex virus types 1 and 2 (HSV-1 and HSV-2)101 and varicella-zoster virus (VZV).101 Also active against cytomegalovirus (CMV), Epstein-Barr virus (EBV), and herpes simiae,a but these viruses not generally associated with dermatologic infections.a

• Resistance to acyclovir reported in HSV and VZV.101

• Some acyclovir-resistant HSV and VZV are cross-resistant to penciclovir.115 116

• Antiviral Agent, Topical

There are no dosage adjustments provided in the manufacturer’s labeling. However, dosage adjustment is unlikely due to low systemic absorption.

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.

Usual Adult Dose for Herpes Simplex Labialis:

Cream: Apply to the affected area 5 times a day for 4 days. Therapy should be started as early as possible following onset of signs and symptoms (i.e., during the prodromal phase or when lesions appear).

Usual Adult Dose for Herpes Simplex:

Ointment: Apply to affected area every 3 hours, 6 times a day for 7 days. Therapy should be started as early as possible following onset of signs and symptoms.

Usual Pediatric Dose for Herpes Simplex Labialis:

Cream:
12 years or older: Apply to the affected area 5 times a day for 4 days. Therapy should be started as early as possible following onset of signs and symptoms (i.e., during the prodromal phase or when lesions appear).

Usual Pediatric Dose for Herpes Simplex:

Ointment:
Children: Apply to affected area every 3 hours, 6 times a day for 7 days. Therapy should be started as early as possible following onset of signs and symptoms.

It is not likely that other drugs you take orally or inject will have an effect on topically applied acyclovir. But many drugs can interact with each other. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

>10%

Burning/stinging (30%)

1-10%

Pruritus (4%)

<1%

Dry lips (<1%)

Rash (0.3%)

Frequency Not Defined

Angioedema

Vulvitis

Contraindications

Hypersensitivity

Cautions

Not recommended for recurrent infections

Use caution in immunocompromised patients

Avoid physical contact when lesions are present

For external use only; not for use on the eye or inside mouth

Commonly reported side effects of acyclovir topical include: burning sensation of skin, stinging of the skin, mild local discomfort, and mild pain. See below for a comprehensive list of adverse effects.

Ointment: Apply to affected area every 3 hours, 6 times a day for 7 days. Therapy should be started as early as possible following onset of signs and symptoms.

Summary of Use during Lactation

Even with the highest maternal dosages, the dosage of acyclovir in milk is only about 1% of a typical infant dosage and would not be expected to cause any adverse effects in breastfed infants. Topical acyclovir applied to small areas of the mother's body away from the breast should pose no risk to the infant. Only water-miscible cream or gel products should be applied to the breast because ointments may expose the infant to high levels of mineral paraffins via licking.[1]

Drug Levels

Maternal Levels. A 4-month-postpartum women was taking 200 mg orally 5 times daily every 4 hours while awake. After 4 days of therapy, milk samples were taken 9 hours after the previous dose and at 4 times after a 200 mg dose. The lowest milk level of 427 mcg/L occurred 30 minutes after the first dose. At 3.2 hours after the dose, the milk acyclovir level was 1.3 mg/L and apparently still increasing.[2]

A woman who was 1 year postpartum was taking acyclovir 200 mg orally 5 times daily. Milk levels taken immediately before a dose during 5 days of therapy ranged from 0.78 to 1.07 mg/L. Samples taken after the last dose decreased with a half-life of 2.8 hours.[3]

A woman who had taken oral acyclovir 400 mg 3 times daily for 3 days in the peripartum period had a breastmilk acyclovir level of 54 mcg/L 5 days after her last dose of acyclovir.[4] A mother nursing her 7-month-old infant took acyclovir 800 mg orally 5 times a day. Three milk acyclovir levels on days 5 and 6 of therapy ranged from 4.2 to 5.8 mg/L, with the highest level 9.4 hours after the previous dose. The authors estimated that a fully breastfed infant would receive 0.73 mg/kg/day of acyclovir at this maternal dosage or about 1% of the maternal weight-adjusted dosage.[5]

A woman who was 6 weeks postpartum received intravenous acyclovir 300 mg (5 mg/kg) 3 times daily for 5 days. Milk samples were taken every 6 hours after the last dose. The peak level was 7.3 mg/L and the drug was detectable in milk for up to 88 hours after the last dose.[6] Using the level 6 hours after the last dose, a fully breastfed infant would receive 1.1 mg/kg/day with this maternal dosage regimen.

Acyclovir is given to neonates in intravenous dosages of 20 to30 mg/kg daily. Dosages received in breastmilk with high maternal doses are only about 3 to 5% of this dose. Because the infant receives breastmilk doses orally and acyclovir is only about 20% orally bioavailable,[5] the systemic dosage that the nursing infant receives is 1% or less of a typical infant dosage.

Infant Levels. A 4-month-old infant whose mother was taking 200 mg orally 5 times was breastfed just before a dose. The infant's urine collected over the next 2 hours contained a total of 27 mcg of acyclovir.[2]

Effects in Breastfed Infants

The mother of a 4-month-old infant noticed no adverse effects in her breastfed infant while she was taking an acyclovir dosage of 800 mg orally 5 times daily.[5]

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

Alternate Drugs to Consider

Valacyclovir

References

1. Noti A, Grob K, Biedermann M et al. Exposure of babies to C(15)-C(45) mineral paraffins from human milk and breast salves. Regul Toxicol Pharmacol. 2003;38:317-25. PMID: 14623482

2. Lau RJ, Emery MG, Galinsky RE. Unexpected accumulation of acyclovir in breast milk with estimation of infant exposure. Obstet Gynecol. 1987;69 (3 pt 2):468-71. PMID: 3808527

3. Meyer LJ, de Miranda P, Sheth N et al. Acyclovir in human breast milk. Am J Obstet Gynecol. 1988;158(3 pt 1):586-8. PMID: 3348321

4. Frenkel LM, Brown ZA, Bryson YJ et al. Pharmacokinetics of acyclovir in the term human pregnancy and neonate. Am J Obstet Gynecol. 1991;164:569-76. PMID: 1847004

5. Taddio A, Klein J, Koren G. Acyclovir excretion in human breast milk. Ann Pharmacother. 1994;28:585-7. PMID: 8068994

6. Bork K, Benes P. Concentration and kinetic studies of intravenous acyclovir in serum and breast milk of a patient with eczema herpeticum. J Am Acad Dermatol. 1995;32:1053-5. PMID: 7751454