Acyclovir (Zovirax®) vs Docosanol (Abreva®)
Based on "Antibiotic and Chemotherapy"
written by Roger G. Finch
Difference between topical Acyclovir and Docosanol
- Docosanol (Abreva®) cream is an acceptable OTC alternative to prescription topical acyclovir (Zovirax®). The only advantage of docosanol is that it is available without a prescription.
- In practice, docosanol cream is hardly any effective than an excipient in treating cold sores4.
- In experimental research5 acyclovir demonstrated more potent antiviral activity than n-docosanol.
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Acyclovir | Docosanol |
• Zovirax® |
• Abreva® |
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Drug class | |
• Synthetic nucleoside analogue active against herpes simplex virus (HSV) | • 22-carbon saturated aliphatic alcohol |
Dose formulations | |
• Topical cream 5% | • Topical cream 10% |
FDA-approved indications | |
• Treatment of recurrent herpes labialis (cold sores) in immunocompetent adults and adolescents 12 years of age and older | |
•Treatment of recurrent herpes labialis (cold sores) in immunocompetent adults and adolescents 12 years of age and older | • Treatment of recurrent herpes labialis (perioral herpes, cold sores, fever blisters). |
Dosage regimen | |
• 5 times per day for 4 days. | • 5 times per day until healed (maximum 10 days) |
Mechanism of action | |
• Acyclovir is an antiviral drug which is highly active against herpes viruses. • Acyclovir interferes with viral DNA polymerase and inhibits the replication of virus. |
• Docosanol is not a true antiviral medication because this agent has no direct virucidal activity by itself. • The antiviral effects of docosanol are due to its inhibition of the viral entry into the cell 3. |
Contraindications | |
• Hypersensitivity to acyclovir, valacyclovir or any component of the formulation | • Hypersensitivity to docosanol or component of the formulation |
Side effects | |
• Burning, stinging or other local skin reactions at the application site | |
Pregnancy category | |
• B | • Not available |
Therapeutic effect | |
• Reduces the duration of cold sores episode by one-half day1. |
• Reduces the duration of cold sores episode by one-half day1. |
• No effects on prevention of progression of herpes lesions. |
Further reading
References
- 1. Prescribing Information for Zovirax® (Acyclovir) PDF
- 2. Prescribing Information for Abreva® (Docosanol) PDF
- 3. Pope LE, Marcelletti JF, Katz LR, Lin JY, Katz DH, Parish ML, Spear PG. The anti-herpes simplex virus activity of n-docosanol includes inhibition of the viral entry process.Antiviral Res. 1998 Dec;40(1-2):85-94.
- 4. Docosanol: new drug. Herpes labialis: barely more effective than an excipient. Prescrire Int. 2009 Jun;18(101):106-7. PubMed
- 5. McKeough MB, Spruance SL.Comparison of new topical treatments for herpes labialis: efficacy of penciclovir cream, acyclovir cream, and n-docosanol cream against experimental cutaneous herpes simplex virus type 1 infection. Arch Dermatol. 2001 Sep;137(9):1153-8.
Published: September 20, 2018
Last reviewed: September 20, 2018
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Interesting facts
- Topical treatments for cold sores are less effective than oral antiviral medications.
- Topical medications decrease healing time and pain duration by less than a day, but require multiple daily applications.