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- What is acyclovir, and how does it work (mechanism of action)?
- What are the uses 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 brand names are available for acyclovir?
Is acyclovir available as a generic drug?
GENERIC AVAILABLE: Yes
Do I need a prescription for acyclovir?
What are the side effects of acyclovir?
The most common side effects are
Other reported side effects include:
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).
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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.
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Related Disease Conditions
STDs in Men
Symptoms of sexually transmitted diseases (STDs) in men include painful urination, bumps or sores on the penis, and penile discharge and itching. Learn about the most common STDs in men.
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.
There 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.
Pityriasis rosea is a rash that begins with a large inflamed patch with well-defined scaly borders on the back, chest, or neck. In 1-2 weeks, the person will develop many smaller patches on his or her trunk, arms, and legs. Symptoms include mild itching and possible sore throat, fatigue, nausea, aching, and decreased appetite. Pityriasis rosea typically resolves on its own and symptoms and signs may be treated with topical steroid creams and oral antihistamines.
Pimple vs. Cold Sore
Pimples are areas of skin inflammation with pus in the center. Cold sores are fluid-filled blisters. Pimples are caused by bacterial overgrowth and inflammation. Cold sores are caused by infection with herpes simplex viruses (HSV-1 and HSV-2). Benzoyl peroxide and sometimes antibiotics treat acne. Antiviral medications accelerate the healing process of oral herpes.
Sexually Transmitted Diseases (STDs)
Common sexually transmitted diseases (STDs) in women include gonorrhea, chlamydia, genital herpes, and HPV infection (genital warts). Learn about types, symptoms, and treatment.
Cold Sores (Oral Herpes, Herpes Labialis)
Cold sores (labial herpes) are caused by herpes simplex virus type 1 infection and often appear on the mouth and lips. Read about treatment causes, symptoms, treatment, and diagnosis of oral herpes.
What Is Genital Herpes in Women?
Genital herpes is a sexually transmitted disease (STD) caused by the herpes simplex virus (HSV). Symptoms of genital herpes include painful blisters and often fever, body aches, and swollen lymph nodes for the first outbreak. Genital herpes is diagnosed with lab tests to test for the presence of the virus. Treatment for genital herpes includes antiviral medications to shorten the duration of the outbreak or reduce the risk of future outbreaks. There is no cure for genital herpes. Condoms may help prevent the spread of genital herpes.
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.
Bell's Palsy (Facial Nerve Problems)
Bell's palsy is one type of facial nerve paralysis. The seventh cranial nerve controls the muscles of the face, and although scientists do not know the exact cause of Bell's palsy, they think it may be due to nerve damage from an infection, for example, the flu, common cold viruses, and more serious infections like meningitis. The symptoms of Bell's palsy vary from person to person, but can include mild weakness to total paralysis, dry eye, dry mouth, eyelid drooping, drooling, mouth drooping, dry mouth, changes in taste, and excessive tearing in one eye.
Are Cold Sores (Fever Blisters) Contagious?
About 20% of cases of cold sores are caused by herpes simplex virus type 2 (HSV-2), and approximately 80% of cold sores are caused by herpes simplex virus type 1 (HSV-1). Cold sores are transmitted by sharing utensils and razors, kissing, and oral sex. There is no cure for cold sores.
Ramsay Hunt Syndrome
Ramsay Hunt syndrome is an infection of a facial nerve that causes a red painful rash with blisters and facial paralysis. Other symptoms of Ramsay Hunt syndrome may include ear pain, hearing loss, dizziness (or vertigo), dry eye, and changes in taste sensation. The herpes zoster virus causes the infection.
What Happens When You Get Shingles When Pregnant?
Becoming infected with chickenpox during pregnancy could cause birth defects in your unborn child. Likewise, shingles could also cause problems for your unborn child. If you are pregnant and haven't had chickenpox, avoid exposure to infected people. Zostavax, the shingles vaccine, can reduce the incidence of shingles by half. Women should wait at least three months after receiving the vaccine before trying to get pregnant.
Sexually Transmitted Diseases and Pregnancy (STDs)
When you are pregnant, many sexually transmitted diseases (STDs) can be especially harmful to you and your baby. These STDs include herpes, HIV/AIDS, genital warts (HPV), hepatitis B, chlamydia, syphilis, gonorrhea, and trichomoniasis. Symptoms include bumps, sores, warts, swelling, itching, or redness in the genital region. Treatment of STDs while pregnant depends on how far along you are in the pregnancy and the progression of the infection.
Treatment & Diagnosis
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