Acyclovir

By

Generic Name: Acyclovir Brand Name(s): Generics only. No brands available.

Uses

What is acyclovir used for?

Acyclovir is an antiviral drug. It slows the growth and spread of the herpes virus in the body. It will not cure herpes, but it can lessen the symptoms of the infection.

Acyclovir is used to treat infections caused by herpes viruses, such as genital herpes, cold sores, shingles, and chicken pox.

Acyclovir may also be used for purposes not listed in this medication guide.

How should I take acyclovir?

Take acyclovir exactly as it was prescribed for you. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Treatment with acyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Shake the oral suspension (liquid) well just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

To take the acyclovir buccal tablet (Sitavig):

  • Keep the tablet in its blister pack until you are ready to take it. Use a dry finger to remove the tablet.
  • Do not chew or swallow a buccal tablet. Place the flat side of the tablet against your upper gum, behind your lip and above your canine tooth. Place the tablet on the same side of the mouth as your cold sore.
  • Close your mouth and gently press on the outside of your lip over the tablet, holding it in place for 30 seconds. Avoid touching or pressing on the tablet once it is in place.
  • Allow the tablet to dissolve in your mouth throughout the day. You may eat and drink normally while the buccal tablet is in place.
  • During the first 6 hours of wearing time: If the tablet falls off or does not stick well, you may replace it with a new tablet. If you accidentally swallow the tablet, drink a glass of water and put a new tablet in place.

Tell your doctor if you have any changes in weight. Acyclovir doses are based on weight (especially in children and teenagers), and any changes may affect the dose.

Drink plenty of water while you are taking acyclovir to keep your kidneys working properly.

Use this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely treated. Acyclovir will not treat a viral infection such as the flu or a common cold.

Lesions caused by herpes viruses should be kept as clean and dry as possible. Wearing loose clothing may help to prevent irritation of the lesions.

How do I store acyclovir?

Acyclovir is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store acyclovir in the bathroom or the freezer. There may be different brands of acyclovir that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush acyclovir down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using acyclovir?

Before using this drug, tell your doctor if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of active or inactive ingredients of acyclovir or other medications.
  • You have any other illnesses, disorders, or medical conditions.

You should not take this medicine if you are allergic to acyclovir or valacyclovir (Valtrex). You should not take acyclovir buccal tablets (Sitavig) if you are allergic to milk proteins.

To make sure acyclovir is safe for you, tell your doctor if you have:

  • Kidney disease
  • A weak immune system (caused by disease or by using certain medicine)

Herpes can be passed to your baby during childbirth if you have a genital lesion when your baby is born. If you have genital herpes, it is very important to prevent herpes lesions during pregnancy. Take your medicine as directed to best control your infection.

Acyclovir passes into breast milk and may harm a nursing infant. Do not take this medication without telling your doctor if you are breast-feeding a baby.

Do not give an acyclovir buccal tablet to a young child or choking could occur.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using acyclovir during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking acyclovir. Acyclovir is pregnancy risk category B, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from acyclovir?

Get emergency medical help if you have any signs of an allergic reaction to acyclovir: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • Easy bruising or bleeding, purple or red pinpoint spots under your skin
  • Signs of a kidney problem -little or no urinating; painful or difficult urination; swelling in your feet or ankles; feeling tired or short of breath

Common side effects may include:

  • Nausea, vomiting
  • Diarrhea
  • General ill feeling
  • Headache
  • Mouth pain while using an acyclovir buccal tablet

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Interactions

What drugs may interact with acyclovir?

Acyclovir may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with acyclovir?

Acyclovir may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with acyclovir?

Acyclovir may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using acyclovir.

What is the dose of acyclovir for an adult?

Usual Adult Dose for Herpes Simplex – Mucocutaneous/Immunocompetent Host

Treatment of First Episode of Genital Herpes:

  • 200 mg orally every 4 hours 5 times a day for 10 days (manufacturer dosing)
  • 400 mg orally 3 times a day for 5 to 10 days (CDC recommendation)

Severe Disease or Complications Requiring Hospitalization:

  • 5 mg/kg IV every 8 hours for 5 days (manufacturer dosing)
  • 5 to 10 mg/kg IV every 8 hours for 2 to 7 days or until clinical improvement is observed, followed by oral antiviral therapy to complete at least 10 days of total therapy (CDC recommendation)

Episodic (Intermittent) Therapy: Effective treatment requires therapy initiation within 1 day of lesion onset or during the prodrome preceding an episode/recurrence

  • 200 mg orally every 4 hours 5 times a day for 5 days (manufacturer dosing)
  • 400 mg orally 3 times a day for 5 days OR 800 mg orally 2 times a day for 5 days OR 800 mg orally 3 times a day for 2 days (CDC recommendations)

Usual Adult Dose for Herpes Simplex – Mucocutaneous/Immunocompromised Host

Concomitant HIV infection:

Treatment of First Episode of Genital Herpes:

  • 400 mg orally 3 times a day for 5 to 10 days (guideline recommendation)
  • Duration of therapy: 5 to 10 days

Severe Disease:

  • 5 mg/kg IV every 8 hours after lesions begin to regress, may change to oral therapy; continue treatment until lesions have completely healed (guideline recommendation)

Episodic (Intermittent) Therapy: Effective treatment requires therapy initiation within 1 day of lesion onset or during the prodrome preceding an episode/recurrence

  • 400 mg orally 3 times a day for 5 to 14 days

Usual Adult Dose for Herpes Simplex Encephalitis

10 mg/kg IV every 8 hours

Duration of therapy: 10 days (manufacturer); 21 days (CDC)

Usual Adult Dose for Herpes Zoster

800 mg orally every 4 hours 5 times a day for 7 to 10 days

Immunocompromised host:

10 mg/kg IV every 8 hours for 7 days

Usual Adult Dose for Varicella-Zoster

Immunocompetent Host: 800 mg orally 4 times a day for 5 days

Immunocompromised Host: 10 mg/kg IV every 8 hours for 7 days

HIV-Infected Adults:

  • Uncomplicated course: 800 mg orally 5 times a day for 5 to 7 days (alternative therapy; oral valacyclovir or famciclovir are preferred therapy)
  • Severe or complicated course: 10 to 15 mg/kg IV every 8 hours for 7 to 10 days; may switch to oral therapy after defervescence if no evidence of visceral involvement

Usual Adult Dose for Herpes Simplex Labialis

Immunocompetent host:

Apply 50 mg (1 buccal tablet) as a single-dose to the upper gum region (canine fossa)

Usual Adult Dose for Herpes Simplex – Suppression

Daily Suppressive Therapy for Recurrent Disease: 400 mg orally 2 times a day

Alternative regimens from 200 mg orally 3 times a day to 200 mg orally 5 times a day have been used.

Concomitant HIV infection: 400 to 800 mg orally 2 to 3 times a day

Usual Adult Dose for Herpes Zoster – Prophylaxis

HIV-Infected Adults (guideline dosing):

Post-Exposure Prophylaxis: 800 mg orally 5 times a day for 5 to 7 days; begin 7 to 10 days after exposure

Usual Adult Dose for Varicella-Zoster – Prophylaxis

HIV-Infected Adults (guideline dosing):

Post-Exposure Prophylaxis: 800 mg orally 5 times a day for 5 to 7 days; begin 7 to 10 days after exposure

What is the dose of acyclovir for a child?

Usual Pediatric Dose for Herpes Simplex – Congenital

Neonatal Herpes:

Birth to 3 months: 10 mg/kg IV every 8 hours for 10 days (manufacturer dosing)

Birth to 3 months: 20 mg/kg IV every 8 hours (CDC recommendation)

Duration of therapy: Disease limited to the skin and mucous membranes: 14 days; Disseminated disease or disease involving the CNS: 21 days

Follow with oral suppressive therapy: 300 mg/m2 orally 3 times a day for 6 months 

Usual Pediatric Dose for Herpes Simplex – Mucocutaneous/Immunocompetent Host

Treatment of First Episode of Genital Herpes:

  • Less than 12 years: 40 to 80 mg/kg/day orally in divided doses 3 to 4 times a day for 5 to 10 days
  • Maximum dose: 1000 mg/day
  • 12 years or older: 200 mg orally every 4 hours 5 times a day OR 400 mg orally 3 times a day
  • Duration of therapy: 7 to 10 days

Severe Disease or Complications Requiring Hospitalization:

  • Less than 12 years: 10 mg/kg IV every 8 hours for 7 days
  • 12 years or older: 5 mg/kg IV every 8 hours for 7 days

Recurrence of Genital HSV Infection:

  • Less than 12 years: 20 to 25 mg/kg orally twice a day; Maximum dose: 400 mg
  • 12 years or older: 200 mg orally 5 times a day for 5 days OR 800 mg orally 2 times a day for 5 days OR 800 mg orally 3 times a day for 2 days

Usual Pediatric Dose for Herpes Simplex Encephalitis

3 months to 12 years old: 10 to 20 mg/kg IV every 8 hours

12 years or older: 10 mg/kg IV every 8 hours

Duration of therapy: 10 days (manufacturer); 21 days (CDC)

Usual Pediatric Dose for Herpes Simplex – Mucocutaneous/Immunocompromised Host

Less than 12 years: 10 mg/kg IV every 8 hours for 7 days (manufacturer dosing)

12 years or older: 5 mg/kg IV every 8 hours for 7 days (manufacturer dosing)

Concomitant HIV infection (guideline dosing):

Mild Symptomatic Gingivostomatitis:

  • 20 mg/kg orally 4 times a day for 7 to 10 days
  • Maximum dose: 400 mg

Moderate to Severe Gingivostomatitis:

  • 5 to 10 mg/kg IV 3 times a day
  • May switch to oral therapy after lesions have begun to regress; treat until lesions have completely healed

Usual Pediatric Dose for Herpes Zoster

Immunocompetent Host:

Parenteral:

  • Less than 1 year: 10 mg/kg IV every 8 hours for 7 to 10 days
  • 1 year or older: 500 mg/m2 IV every 8 hours for 7 to 10 days

Oral: 12 years or older: 800 mg orally 5 times a day for 5 to 7 days

Immunocompromised Host: 10 mg/kg IV every 8 hours for 7 to 10 days

HIV-exposed and HIV-Infected Children:

Uncomplicated Zoster:

  • 20 mg/kg orally 4 times a day for 7 to 10 days; Maximum dose: 800 mg

Severe immunosuppression (CDC immunologic category 3), trigeminal or sacral nerve involvement, extensive multidermatomal, or disseminated zoster:

  • 10 mg/kg IV every 8 hours until cutaneous lesions and visceral disease are clearly resolving; then may switch to oral therapy to complete a 10 to 14-day course

HIV-Infected Adolescents:

  • Localized Dermatomal: 800 mg orally 5 times a day for 7 to 10 days (alternative therapy; oral valacyclovir or famciclovir are preferred therapy)
  • Extensive Cutaneous Lesion or Visceral Involvement: 10 to 15 mg/kg IV every 8 hours until clinical improvement (i.e. no new vesicle formation or improvement of signs and symptoms of visceral disease), then switch to oral therapy
  • Duration of therapy: 7 to 14-day course (oral plus IV)

Usual Pediatric Dose for Varicella-Zoster

Immunocompetent host:

2 years or older (40 kg or less): 20 mg/kg orally 4 times a day for 5 days

2 years or older (over 40 kg): 800 mg orally 4 times a day for 5 days

Maximum doses: Single: 800 mg; Daily: 3200 mg/day

Immunocompromised host:

  • Less than 1 year: 10 mg/kg IV 3 times a day for 7 to 10 days
  • 1 year or older: 500 mg/m2 IV 3 times a day for 7 to 10 days

HIV-exposed and HIV-infected Children

  • Mild disease with no or moderate immune suppression (CDC immunologic category 1 and 2): 20 mg/kg orally 4 times a day for 7 to 10 days and until no new lesions for 48 hours
  • Maximum dose: 800 mg

Severe immune suppression (CDC immunologic category 3): 10 mg/kg or 500 mg/m2 IV every 8 hours for 7 to 10 days and until no new lesions for 48 hours

HIV-Infected Adolescents:

  • Uncomplicated course: 800 mg orally 5 times a day for 5 to 7 days (alternative therapy; oral valacyclovir or famciclovir are preferred therapy)
  • Severe or complicated course: 10 to 15 mg/kg IV every 8 hours for 7 to 10 days; may switch to oral therapy after defervescence if no evidence of visceral involvement

Usual Pediatric Dose for Herpes Simplex – Suppression

Neonatal period (less than 1 year): 300 mg/m2 orally 3 times a day for 6 months

Secondary Prophylaxis in HIV-Exposed and HIV-infected Children:

  • 20 mg/kg orally twice a day
  • Maximum dose: 800 mg

Usual Pediatric Dose for Herpes Simplex Labialis

Concomitant HIV infection:

  • 20 mg/kg orally 4 times a day for 5 days
  • Maximum dose: 400 mg

Adolescents: 400 mg orally 3 times a day for 5 to 10 days

Usual Pediatric Dose for Herpes Zoster – Prophylaxis

HIV-Infected Children or Adolescents (guideline dosing):

Post-exposure Prophylaxis in HIV-Infected Children or Adolescents:

20 mg/kg orally 4 times a day (maximum dose 800 mg) for 7 days beginning 7 to 10 days after exposure

Usual Pediatric Dose for Varicella-Zoster – Prophylaxis

HIV-Infected Children or Adolescents (guideline dosing):

Post-exposure Prophylaxis in HIV-Infected Children or Adolescents:

20 mg/kg orally 4 times a day (maximum dose 800 mg) for 7 days beginning 7 to 10 days after exposure

How is acyclovir available?

Acyclovir is available in the following dosage forms and strengths:

  • Injection

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of acyclovir, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: September 14, 2017 | Last Modified: September 14, 2017

Sources
You might also like