This article describes acyclovir oral tablet’s dosages, its strengths, and details on how to take it. You’ll also find information on cost savings and coupon options for acyclovir.
Acyclovir oral tablet is a generic medication. It doesn’t come in a brand-name version. Acyclovir also comes in oral capsule, oral suspension, and injectable forms, but these forms aren’t described in this article. To learn more about these forms, talk with your doctor.
If you want to know more about acyclovir oral tablet, see this overview article. It covers details about the drug’s uses, side effects, and more.
Form and strengths of acyclovir
Acyclovir oral tablet is swallowed. It comes in the following strengths:
- 400 milligrams (mg)
- 800 mg
Dosage of acyclovir
This article describes the recommended dosages* for acyclovir oral tablet.
If your doctor prescribes this medication, they’ll determine the dosage that’s best for you. Do not change your dosage of acyclovir oral tablet without your doctor’s recommendation.
* The drugmaker provides these recommended dosages. If your doctor prescribes acyclovir, be sure to take the dosage they prescribe for you.
Usual recommended dosages of acyclovir in adults
Acyclovir is approved to treat genital herpes, chickenpox, and shingles in adults.
Usually, doctors start by prescribing a low acyclovir oral tablet dose. Then, they’ll adjust it over time until the right dosage is reached. Ultimately, your doctor will prescribe the smallest dosage of acyclovir oral tablet that gives the desired outcome.
The table below describes dosages that are commonly prescribed. That said, always take the dosage your doctor prescribes for you. Your doctor will determine the dosage that best meets your needs. Doses are listed in milligrams (mg).
Condition | Dose | Frequency |
genital herpes, suppression* | 400 mg | 2 times per day for up to 12 months |
chickenpox | 800 mg | 4 times per day for 5 days |
shingles (also called herpes zoster) | 800 mg | 5 times per day for 7 to 10 days |
* This treatment with acyclovir tablet prevents the infection from becoming active again. But to treat a first infection of genital herpes, doctors may use the capsule form of acyclovir. Doctors may also use the capsule form of acyclovir to treat a genital herpes infection that becomes active again.
Dosages of acyclovir in children
Acyclovir is approved to treat chickenpox in children ages 2 to 17 years. Children’s dosages are based on the child’s weight. (For reference, 1 kilogram [kg] equals about 2.2 pounds [lb].)
Body weight in kg | Approximate body weight in lb | Dose | Frequency |
40 kg or less | 88 lb or less | 20 mg per kg (mg/kg) | 4 times per day for 5 days |
more than 40 kg | more than 88 lb | 800 mg | 4 times per day for 5 days |
For example, assume a doctor prescribes acyclovir oral tablet for a child who weighs 20 kg (about 44 lb). The dosage would be 400 mg, to be taken four times per day for 5 days.
Dosage adjustments for acyclovir
Your doctor will prescribe a dosage of acyclovir oral tablet based on several factors, including:
- the specific condition being treated and how severe it is
- age
- child’s body weight
- other health conditions
Missed dose of acyclovir
Talk with your doctor or pharmacist right away if you realize you forgot to take a dose of acyclovir oral tablet. They may advise you to take the missed dose. Or they may advise you to skip it and take your next dose as scheduled.
For tips on how to plan your doses of acyclovir oral tablet and avoid missing a dose, read this article. You could also try:
- downloading a reminder app on your phone
- setting an alarm
- putting a note where you’ll see it, such as on your calendar, bathroom mirror, or bedside table
Frequently asked questions
Below are answers to some commonly asked questions about acyclovir oral tablet and its dosage.
Is there a 400-mg or 800-mg dose of acyclovir for cold sores?
Although acyclovir oral tablet isn’t approved to treat cold sores, this is a common off-label use. With off-label use, doctors prescribe a drug for a purpose other than its approved uses.
The same virus that causes genital herpes causes cold sores (oral herpes). The dose of acyclovir doctors prescribe to treat cold sores is based on expert opinion and medical research.
You can talk with your doctor about treatments that may help lessen your symptoms of cold sores.