- Sexually Transmitted Diseases (STDs) Slideshow Pictures
- Image Collection: Picture of Genital Warts (HPV)
- Take the Genital Herpes Quiz
- What is acyclovir, and how does it work (mechanism of action)?
- What brand names are available for acyclovir?
- Is acyclovir available as a generic drug?
- Do I need a prescription for acyclovir?
- What are the side effects of acyclovir?
- What is the dosage for acyclovir?
- Which drugs or supplements interact with acyclovir?
- Is acyclovir safe to take if I'm pregnant or breastfeeding?
- What else should I know about acyclovir?
What is acyclovir, and how does it work (mechanism of action)?
Acyclovir is an antiviral drug, a synthetic nucleoside analogue, that has inhibitory activity (interferes with viral replication) against the herpes viruses, including herpes simplex 1 and 2 (cold sores and genital herpes), varicella-zoster (shingles and chickenpox), and Epstein-Barr virus (mononucleosis). Viruses take over living cells and reproduce themselves, often at the expense of the host cell. The acyclovir is converted to an active form by the virus itself, and the virus then uses the active form of acyclovir rather than the nucleoside it normally uses to manufacture DNA, a critical component of viral replication. Incorporation of active acyclovir into new viral DNA stops the production of the DNA. Virally infected cells absorb more acyclovir than normal cells and convert more of it to the active form, which prolongs its antiviral activity. The FDA approved acyclovir in March 1982.
What is the dosage for acyclovir?
Acyclovir may be taken with or without food.
- Adult oral doses for treating genital herpes are 200 mg every 4 hours (5 times daily) for 7-10 days or 400 mg three times daily for 5-10 days.
- Herpes Zoster (shingles) is treated with 800 mg every 4 hours (5 times daily) for 7 to 10 days.
- The dose for treating chicken pox is 800 mg 4 times daily. The usual adult intravenous dose is 5-10 mg/kg every 8 hours for 7-10 days.
Which drugs or supplements interact with acyclovir?
Acyclovir may decrease levels of phenytoin (Dilantin) or valproic acid (Depakote, Depakote ER). Probenecid (Benemid) may increase acyclovir serum levels by decreasing renal excretion of acyclovir. Acyclovir may increase serum levels of theophylline (Theo-Dur, Respbid, Slo-Bid, Theo-24, Theolair, Uniphyl, Slo-Phyllin).
Is acyclovir safe to take if I'm pregnant or breastfeeding?
There are no adequate studies of acyclovir in pregnant women. In a patient registry of women who used acyclovir during the first trimester, the rate of birth defects was similar to the rate of birth defects in the general population.
Acyclovir is excreted in breast milk, and a significant amount may be transferred to the infant.
What else should I know about acyclovir?
What preparations of acyclovir are available?
- Capsules: 200 mg.
- Tablets: 400 and 800 mg.
- Suspension: 200 mg/5 ml.
- Injection: 50 mg/ml.
- Powder for injection: 500 and 1000 mg.
- Ointment: 5%.
How should I keep acyclovir stored?
Acyclovir should be stored at room temperature, between 15 C 25 C (59 F to 77 F).
Acyclovir (Zovirax) is an antiviral drug prescribed to treat genital herpes, shingles, and chickenpox. Side effects drug interactions, dosing, storage, and pregnancy safety information should be reviewed prior to taking this medication.
Multimedia: Slideshows, Images & Quizzes
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Top acyclovir Related Articles
Chickenpox (Varicella)Chickenpox (chicken pox) is a contagious childhood disease caused by the varicella-zoster virus. Symptoms have an incubation period of 14 to 16 days and include a couple days of mild fever, weakness, and red, raised rash that progresses to blisters that eventually burst and crust over. Complications include bacterial infection of the open sores, scarring, encephalitis, nerve palsies, and Reye's syndrome.
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Facial Nerve Problems
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National Institute of Neurological Disorders and Stroke (NINDS). "NINDS Bell's Palsy Information Page." Updated: Apr 16, 2015.
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NIH. National Center for Advancing Translational Sciences. "Bell's Palsy."
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Shingles (Herpes Zoster)Shingles, or herpes zoster, is a painful rash caused by the varicella zoster virus. Other shingles symptoms include headache, fever, nausea, and body aches. Treatment focuses on pain management and shortening the duration of the illness with antiviral medications.
Take the Shingles QuizShingles falls within a well-known family of viruses that cause itching, burning, blisters, and pain. Take the Shingles Quiz to get the facts, causes, symptoms, and treatments for this itchy, painful condition.
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Tongue ProblemsThere are a variety of diseases and conditions that can cause tongue problems, discoloration, and soreness. Though most tongue problems are not serious. Conditions such as leukoplakia, oral thrush, and oral lichen planus may cause a white tongue while Kawasaki syndrome, scarlet fever, and geographic tongue may cause the tongue to appear red. A black hairy tongue may be caused by overgrown papillae on the tongue. Canker sores, smoking, and trauma may cause soreness of the tongue.