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Acyclovir topical Side Effects

Medically reviewed by Last updated on Aug 25, 2023.

Applies to acyclovir topical: topical cream, topical ointment.

Serious side effects of Acyclovir topical

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

Other side effects of Acyclovir topical

Some side effects of acyclovir topical 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

Less common


For Healthcare Professionals

Applies to acyclovir topical: topical cream, topical ointment.


The more commonly reported adverse effects have included local application site reactions including transient stinging and burning.[Ref]


Very common (10% or more): Mild pain including transient burning and stinging (30%) at application site

Common (1% to 10%): Local pruritus

Rare (less than 0.1%): Erythema

Frequency not reported: Dry lips, desquamation, dryness of skin, cracked lips, burning skin, flakiness of skin

Postmarketing reports: Contact dermatitis, eczema[Ref]

The incidence of events between the drug and placebo group appears to be similar. Where sensitivity tests have been conducted, the reactive substance has often been the component of the cream rather than the active drug.[Ref]


Postmarketing reports: Angioedema, anaphylaxis


Postmarketing reports: Edema


1. (2017) "Product Information. Zovirax (acyclovir)." Mylan Pharmaceuticals Inc

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. (2017) "Product Information. Zovirax Topical (acyclovir topical)." Valeant Pharmaceuticals

4. Wagstaff AJ, Faulds D, Goa KL (1994) "Aciclovir: a reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic efficacy." Drugs, 47, p. 153-205

5. Reichman RC, Badger GJ, Guinan ME, Nahmias AJ, Keeney RE, Davis LG, Ashikaga T, Dolin R (1983) "Topically administered acyclovir in the treatment of recurrent herpes simplex genitalis: a controlled trial." J Infect Dis, 147, p. 336-40

6. Corey L, Nahmias AJ, Guinan ME, Benedetti JK, Critchlow CW, Holmes KK (1982) "A trial of topical acyclovir in genital herpes simplex virus infections." N Engl J Med, 306, p. 1313-9

7. Gola M, Francalanci S, Brusi C, Lombardi P, Sertoli A (1989) "Contact sensitization to acyclovir." Contact Dermatitis, 20, p. 394-5

8. Gnann JW Jr, Barton NH, Whitley RJ (1983) "Acyclovir: mechanism of action, pharmacokinetics, safety and clinical applications." Pharmacotherapy, 3, p. 275-83

9. Koch P (1995) "No evidence of contact sensitization to acyclovir in acute dermatitis of the lips following local application of zovirax cream." Contact Dermatitis, 33, p. 255-7

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.