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acyclovir - Zovirax (and other generic drugs)

General Information Acyclovir is an antibiotic used to treat several different viral infections.
Specifics Acyclovir is a well-respected and very effective medication.  Acyclovir has a VERY long track record of effectiveness and safety. 

Acyclovir works by inhibiting the production of proteins within certain viruses.

Dosing Acyclovir is available as tablets or capsules in a variety of strengths.

The dose varies but usually it is taken at least 3 times per day for treatment of infection or twice a day to prevent infection or recurrences of infection.

Genital or lip herpes treatment:  usually 200 mg 5 times per day (while awake) or 400 mg three times per day until all the herpes spots are crusted or have a scab
Shingles or herpes zoster: 
usually 800 mg 5 times per day (while awake) until all the shingles spots are crusted or have a scab
Oral hairy leukoplakia:
usually 800 mg 5 times per day (while awake) until the white marks on the tongue are gone

This refers to your willingness, ability, and actual performance in taking your medications.

For further information and tips on adherence, go to the Adherence section of this site.

It is very important to take every dose that is prescribed unless instructed by your healthcare provider.

If the medication is not taken correctly or long enough, the infection may come back or possibly even develop resistance to the acyclovir.

Do not adjust the amount of the dose or the frequency of acyclovir without speaking to your healthcare provider first.

Possible Side Effects
The package insert for most drugs including acyclovir is often overwhelming and scary with perhaps an overemphasis on side effects.  We have summarized the important and more common problems here.

Most people take acyclovir without any or very many side effects.  

Many side effects get better with time.

The most frequent side effect of acyclovir is nausea, tremor, rash.

If one takes acyclovir in high doses when one is dehydrated, acyclovir can cause problems with the kidneys.  Therefore, do not take acyclovir if you are having difficulty with fluid intake due to nausea and vomiting.

Always drink plenty of fluids when you are taking acyclovir.

This refers to the way that
acyclovir affects other medications and how other medications might affect acyclovir.

Make sure that your healthcare provider is aware of all the medications you are taking so that important and possibly dangerous interactions are not overlooked.

Acyclovir can interact with other medications that can cause decreased kidney performance such as furosemide (Lasix), other diuretics, ibuprofen (and all other anti-inflammatory drugs such as sulindac, naproxen,) gentamicin (and other aminoglycoside antibiotics,) and amphotericin B.  Always drink plenty of fluids if you are taking acyclovir.

Valacylcovir (Valtrex), famciclovir (Famvir), ganciclovir , valganciclovir (Valcyte), and cidofovir (Vistide) should not be taken with acyclovir as they are treating the same infection and can cause extra kidney problems.

Report to you healthcare provider or go to an Emergency Room if you have severe side effects, increasing side effects, increasing shortness of breath, fever, eye pain or redness, loss of vision, jaundice (eyes and skin turn yellow,) nausea and vomiting (so that you cannot hold down your food and liquids) or rash.
You can download this handout in PDF format by clicking HERE.