Medical Editor: John P. Cunha, DO, FACOEP
Zovirax (acyclovir) Cream, 5% is a herpes simplex virus (HSV) nucleoside analogue DNA polymerase inhibitor used to treat recurrent herpes labialis (cold sores) in immunocompetent adults and adolescents 12 years of age and older. Common side effects of Zovirax Cream include:
- application site reactions such as dry lips,
- skin sloughing,
- skin dryness,
- cracked lips,
- burning skin,
- flakiness of skin,
- contact dermatitis,
- skin swelling, and
- temporary burning or stinging on skin where the medication is applied.
Zovirax Cream should be applied five times per day for four days. Therapy should be initiated as early as possible following the onset of signs or symptoms of herpes labialis i.e., during the prodrome or when lesions appear. Zovirax may interact with other drugs. Tell your doctor all medications and supplements you use. Tell your doctor if you are pregnant or plan to become pregnant before using Zovirax Cream. It is unknown if topically applied acyclovir passes into breast milk. Oral forms of this drug pass into breast milk. Do not nurse if you have lesions on or near the breasts. Consult your doctor before breastfeeding.
Our Zovirax (acyclovir) Cream, 5% Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
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.
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug, and may not reflect the rates observed in practice.
In five double-blind, placebo-controlled trials, 1,124 patients were treated with ZOVIRAX Cream and 1,161 with placebo (vehicle) cream. Local application site reactions were reported by 5% of patients receiving ZOVIRAX Cream and 4% of patients receiving placebo. The most common adverse reactions at the site of topical application were dry lips, desquamation, dryness of skin, cracked lips, burning skin, pruritus, flakiness of skin, and stinging on skin; each adverse reaction occurred in less than 1% of patients receiving ZOVIRAX Cream and placebo. Three patients on ZOVIRAX Cream and one patient on placebo discontinued treatment due to an adverse event.
An additional study, enrolling 22 healthy adults, was conducted to evaluate the dermal tolerance of ZOVIRAX Cream compared with vehicle using single occluded and semi-occluded patch testing methodology. Both ZOVIRAX Cream and placebo showed a high and cumulative irritation potential. Another study, enrolling 251 healthy adults, was conducted to evaluate the contact sensitization potential of ZOVIRAX Cream using repeat insult patch testing methodology. Of 202 evaluable subjects, possible cutaneous sensitization reactions were observed in the same 4 (2%) subjects with both ZOVIRAX Cream and placebo, and these reactions to both ZOVIRAX Cream and placebo were confirmed in 3 subjects upon rechallenge. The sensitizing ingredient(s) has not been identified.
The safety profile in patients 12 to 17 years of age was similar to that observed in adults.
In addition to adverse events reported from clinical trials, the following events have been identified during post-approval use of acyclovir cream. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to acyclovir cream.
Read the entire FDA prescribing information for Zovirax Cream (Acyclovir Cream, 5%)