Drug description
Acyclovir is used to treat shingles as well as herpes simplex virus and other types of herpes virus
infections which can cause painful blisters and lesions. Acyclovir reduces the severity of outbreaks
and prevents the development of new blisters. Acyclovir cannot treat CMV disease, which is also
caused by a herpes virus. Acyclovir can prevent herpes simplex outbreaks, which may help people
co-infected with HIV and herpes simplex live longer. High dose acyclovir is used to treat hairy
leukoplakia , a viral infection that usually shows up on the sides of the tongue.
Side effects
Acyclovir has a good toxicity profile, meaning that long term use does not produce major side
effects. Stomach upset, headache or nausea are possible. Hair loss from prolonged use has been
reported.
Dosage
Acyclovir is available in ointment, pill, liquid, and intravenous (injection) forms. Ointment is
applied every 3 hours, 6 times per day for 7 days. Pills come in doses of 800 mg and 200 mg. Severe
acute episodes that do not respond to oral medications can be treated with IV acyclovir. Resistant
strains can be treated with foscarnet (Foscavir). For shingles, the 800 mg tablet is used unless IV
treatment is needed. You cannot take ddC with acyclovir until you are stable on acyclovir. Dosage
reduction is required if you have kidney failure. If you are pregnant or breast feeding, it is
recommended that you do not take acyclovir.
How long it may take to work
Herpes sores usually disappear in a few days after starting treatment. Effectiveness is noted by
crusting over and healing of sores. Long-term therapy with acyclovir may be required if you have
chronic outbreaks of herpes.
Some commonly used brand names are:
In the U.S.-
Zovirax
In Canada-
Alti-Acyclovir
Avirax
Zovirax
Zovirax Wellstat Pac
Zovirax Zostab Pac
Another commonly used name is aciclovir .
Description
Acyclovir (ay-SYE-kloe-veer) belongs to the family of medicines called antivirals, which
are used to treat infections caused by viruses. Usually these medicines work for only one kind or
group of virus infections.
Acyclovir is used to treat the symptoms of chickenpox, shingles, herpes virus infections of the
genitals (sex organs), the skin, the brain, and mucous membranes (lips and mouth), and widespread
herpes virus infections in newborns. Acyclovir is also used to prevent recurrent genital herpes
infections. Although acyclovir will not cure herpes, it does help relieve the pain and discomfort
and helps the sores (if any) heal faster.
Acyclovir may also be used for other virus infections as determined by your doctor. However, it does
not work in treating certain virus infections, such as the common cold.
Acyclovir is available only with your doctor's prescription, in the following dosage forms:
Oral
Capsules (U.S. and Canada)
Oral suspension (U.S. and Canada)
Tablets (U.S. and Canada)
Parenteral
Injection (U.S. and Canada)
Before Using This Medicine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the
good it will do. This is a decision you and your doctor will make. For acyclovir, the following
should be considered:
Allergies-Tell your doctor if you have ever had any unusual or allergic reaction to acyclovir,
ganciclovir, or valacyclovir. Also tell your health care professional if you are allergic to any
other substances, such as foods, sulfites or other preservatives, or dyes.
Pregnancy-Acyclovir has been used in pregnant women and has not been reported to cause birth defects
or other problems. However, studies have not been done in humans. Studies in rabbits have shown that
acyclovir given by injection may keep the fetus from becoming attached to the lining of the uterus
(womb). However, acyclovir has not been shown to cause birth defects or other problems in mice given
many times the usual human dose, or in rats or rabbits given several times the usual human dose.
Breast-feeding-Acyclovir passes into breast milk. However, it has not been reported to cause
problems in nursing babies.
Children-A limited number of studies have been done using oral acyclovir in children, and it has not
caused different effects or problems in children than it does in adults.
Older adults-Acyclovir has been used in the elderly and has not been shown to cause different side
effects or problems in older people than it does in younger adults. However, some of the side
effects involving the central nervous system, for example, agitation, confusion, dizziness, and
drowsiness, may be more severe in older adults.
Other medicines-Although certain medicines should not be used together at all, in many cases two
different medicines may be used together even if an interaction might occur. In these cases, changes
in dose or other precautions may be necessary. If you are taking acyclovir it is especially
important that your health care professional know if you are taking any of the following:
Carmustine (e.g., BiCNU) or
Cisplatin (e.g., Platinol) or
Combination pain medicine containing acetaminophen and aspirin (e.g., Excedrin) or other salicylates
or
Cyclosporine (e.g., Sandimmune) or
Deferoxamine (e.g., Desferal) (with long-term use) or
Gold salts (medicine for arthritis) or
Inflammation or pain medicine, except narcotics, or
Lithium (e.g., Lithane) or
Methotrexate (Mexate) or
Other medicine for infection or
Penicillamine (e.g., Cuprimine) or
Plicamycin (e.g., Mithracin) or
Streptozocin (e.g., Zanosar) or
Tiopronin (Thiola)-Concurrent use of these medicines with acyclovir may increase the chance for side
effects, especially when kidney disease is present
Other medical problems-The presence of other medical problems may affect the use of acyclovir. Make
sure you tell your doctor if you have any other medical problems, especially:
Dehydration or Kidney disease-Dehydration or kidney disease may increase blood levels of acyclovir,
increasing the chance of side effects
Nerve disease-Acyclovir by injection may increase the chance for nervous system side effects
Proper Use
Patient information about the treatment of herpes, chickenpox, or shingles is available
with this medicine. Read it carefully before using this medicine.
Acyclovir is best used as soon as possible after the symptoms of herpes infection or shingles (for
example, pain, burning, blisters) begin to appear .
If you are taking acyclovir for the treatment of chickenpox , it is best to start taking acyclovir
as soon as possible after the first sign of the chickenpox rash , usually within one day.
Acyclovir capsules, tablets, and oral suspension may be taken with meals or on an empty stomach.
If you are using acyclovir oral suspension , use a specially marked measuring spoon or other device
to measure each dose accurately. The average household teaspoon may not hold the right amount of
liquid.
Acyclovir is best taken with a full glass (8 ounces) of water.
To help clear up your herpes infection, chickenpox, or shingles, keep taking acyclovir for the full
time of treatment , even if your symptoms begin to clear up after a few days. Do not miss any doses
. However, do not use this medicine more often or for a longer time than your doctor ordered .
Dosing-The dose of acyclovir will be different for different patients. Follow your doctor's orders
or the directions on the label . The following information includes only the average doses of
acyclovir. Your dose may be different if you have kidney disease. If your dose is different, do not
change it unless your doctor tells you to do so.
The number of capsules or tablets or teaspoonfuls of suspension that you take depends on the
strength of the medicine. Also, the number of doses you take each day, the time allowed between
doses, and the length of time you take the medicine depend on the medical problem for which you are
taking acyclovir .
For oral dosage forms (capsules, oral suspension, or tablets):
For treatment of genital herpes:
Adults and children 12 years of age and older-200 milligrams (mg) five times a day for ten days.
Children up to 12 years of age-Use and dose must be determined by the doctor.
For prevention of recurrent outbreaks of genital herpes infections:
Adults and children 12 years of age and older-200 to 400 mg two to five times a day for five days or
up to twelve months, depending on how often your outbreaks of infection occur.
Children up to 12 years of age-Use and dose must be determined by the doctor.
For treatment of chickenpox:
Adults and children who weigh over 88 pounds (40 kilograms)-800 mg four times a day for five days.
Children 2 years of age and older and weighing 88 pounds (40 kilograms) or less-Dose is based on
body weight and must be determined by the doctor. The usual dose is 20 mg per kilogram (kg) of body
weight, up to 800 mg, four times a day for five days.
Children up to 2 years of age-Use and dose must be determined by the doctor.
For treatment of shingles:
Adults and children 12 years of age and older-800 mg five times a day for seven to ten days.
Children up to 12 years of age-Use and dose must be determined by the doctor.
For injection dosage form:
For treatment of herpes of the brain, genitals, or mucous membranes, or for the treatment of
shingles:
Adults and children 12 years of age and older-Dose is based on body weight and must be determined by
the doctor. The usual dose is 5 to 10 mg of acyclovir per kg (2.3 to 4.5 mg per pound) of body
weight, injected slowly into a vein over at least a one-hour period, and repeated every eight hours
for five to ten days.
Children up to 12 years of age-Dose is based on body weight and must be determined by the doctor.
The usual dose is 10 mg to 20 mg of acyclovir per kg (4.5 mg to 9.1 mg per pound) of body weight,
injected slowly into a vein over at least a one-hour period and repeated every eight hours for seven
to ten days.
For treatment of widespread herpes virus infection in newborns:
Infants from birth to 3 months of age-Dose is based on body weight and must be determined by the
doctor. The usual dose is 10 mg of acyclovir per kg (4.5 mg per pound) of body weight, injected
slowly into a vein over at least a one-hour period and repeated every eight hours for ten days.
Missed dose-If you do miss a dose of this medicine, take it as soon as possible. However, if it is
almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do
not double doses.
Storage-To store this medicine:
Keep out of the reach of children.
Store away from heat and direct light.
Do not store the capsule or tablet form of this medicine in the bathroom, near the kitchen sink, or
in other damp places. Heat or moisture may cause the medicine to break down.
Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is
out of the reach of children.
Precautions
If your symptoms do not improve within a few days, or if they become worse, check with your
doctor.
The areas affected by herpes, chickenpox, or shingles should be kept as clean and dry as possible.
Also, wear loose-fitting clothing to avoid irritating the sores (blisters).
It is important to remember that acyclovir will not keep you from spreading herpes to others .
Herpes infection of the genitals can be caught from or spread to your partner during any sexual
activity. Even though you may get herpes if your partner has no symptoms, the infection is more
likely to be spread if sores are present. This is true until the sores are completely healed and the
scabs have fallen off. Therefore, it is best to avoid any sexual activity if either you or your
sexual partner has any symptoms of herpes . The use of a latex condom (``rubber'') may help prevent
the spread of herpes. However, spermicidal (sperm-killing) jelly or a diaphragm will probably not
help.
