Acyclovir

Name: Acyclovir

Warnings

ZOVIRAX (acyclovir) Capsules, Tablets, and Suspension are intended for oral ingestion only. Renal failure, in some cases resulting in death, has been observed with acyclovir therapy (see ADVERSE REACTIONS: Observed During Clinical Practice and OVERDOSAGE). Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), which has resulted in death, has occurred in immunocompromised patients receiving acyclovir therapy.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Acyclovir

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Capsules

200 mg*

Acyclovir Capsules

Actavis, Ranbaxy, Teva, Watson

Zovirax (with parabens)

GlaxoSmithKline

Suspension

200 mg/5 mL*

Acyclovir Suspension (with parabens)

Actavis, Hi-Tech

Zovirax (with glycerin, parabens, and sorbitol)

GlaxoSmithKline

Tablets

400 mg*

Acyclovir Tablets

Actavis, Ranbaxy, Teva, Watson

Zovirax (with povidone)

GlaxoSmithKline

800 mg*

Acyclovir Tablets

Actavis, Ranbaxy, Teva, Watson

Zovirax (with povidone)

GlaxoSmithKline

Acyclovir Sodium

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Parenteral

For injection, concentrate, for IV infusion only

50 mg (of acyclovir) per mL (500 mg, 1 g)

Acyclovir Sodium Injection

Abraxis

For injection, for IV infusion only

500 mg (of acyclovir)

Acyclovir Sodium for Injection

Abraxis, Bedford, Sicor

Zovirax

GlaxoSmithKline

1 g (of acyclovir)

Acyclovir Sodium for Injection

Abraxis, Bedford, Sicor

Zovirax

GlaxoSmithKline

Acyclovir Sodium in Sodium Chloride

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Parenteral

Injection, for IV infusion only

5 mg (of acyclovir) per mL [500 mg, 1 g] in 0.9% Sodium Chloride

Acyclovir Sodium Injection in 0.9% Sodium Chloride Injection Redi-Infusion

ESI Lederle

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.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include agitation, seizure (convulsions), or loss of consciousness.

What other drugs will affect acyclovir?

Acyclovir can harm your kidneys. This effect is increased when you also use certain other medicines, including: probenecid, antivirals, chemotherapy, injected antibiotics, medicine for bowel disorders, medicine to prevent organ transplant rejection, injectable osteoporosis medication, and some pain or arthritis medicines (including aspirin, Tylenol, Advil, and Aleve).

Other drugs may interact with acyclovir, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Usual Adult Dose for Herpes Simplex Encephalitis

10 mg/kg IV every 8 hours
Duration of therapy: 10 days (manufacturer); 21 days (CDC)

Comments:
-The Center for Disease Control and Prevention (CDC) recommends 21 days of IV therapy to treat HSV encephalitis.

Use: For the treatment of HSV encephalitis.

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

Comments:
-Varicella-zoster immune globulin is the preferred therapy for postexposure prophylaxis; oral antiviral therapy may be used when passive immunization is not possible; if antiviral therapy is used, varicella vaccines should not be given for at least 72 hours following last dose.
-Guidelines for the Prevention and Treatment of Opportunistic Infections Among HIV- Infected Adults and Adolescents may be consulted for additional guidance.

Use: For HIV-infected person who has had close contact with a person who has active varicella or herpes zoster and is susceptible to the virus (e.g. no history of vaccination or either condition, or is known to be seronegative).

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

Comments:
-Varicella-zoster immune globulin is the preferred therapy for postexposure prophylaxis; oral antiviral therapy may be used when passive immunization is not possible; if antiviral therapy is used, varicella vaccines should not be given for at least 72 hours following last dose.
-Guidelines for the Prevention and Treatment of Opportunistic Infections Among HIV- Infected Adults and Adolescents may be consulted for additional guidance.

Use: For HIV-infected person who has had close contact with a person who has active varicella or herpes zoster and is susceptible to the virus (e.g. no history of vaccination or either condition, or is known to be seronegative).

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

Comments:
-Acyclovir is the drug of choice for local and disseminated herpes simplex in HIV-infected and exposed infants and children; children with severe immunosuppression and moderate to severe lesions should be treated initially with IV therapy and may require longer therapy.
-Immunocompromised patients may have prolonged or severe episodes; clinical manifestations of genital herpes may worsen during immune reconstitution early after initiation of antiretroviral therapy.
-CDC STD Treatment Guidelines and the Guidelines for the Prevention and Treatment of Opportunistic Infections Among HIV- Exposed and HIV-Infected Children may be consulted for additional guidance.

Use: For the treatment of initial and recurrent mucosal and cutaneous herpes simplex (HSV-1 and HSV-2) in immunocompromised patients

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

Comments:
-Varicella-zoster immune globulin is the preferred therapy for postexposure prophylaxis; oral antiviral therapy may be used when passive immunization is not possible; if antiviral therapy is used, varicella vaccines should not be given for at least 72 hours following last dose.
-Guidelines for the Prevention and Treatment of Opportunistic Infections Among HIV- Exposed and HIV-Infected Children or HIV- Infected Adults and Adolescents may be consulted for additional guidance.

Use: For HIV-infected person who has had close contact with a person who has active varicella or herpes zoster and is susceptible to the virus (e.g. no history of vaccination or either condition, or is known to be seronegative).

Dialysis

Hemodialysis: Adjust dosing interval to provide an additional dose after each dialysis
Peritoneal Dialysis: No supplemental dose necessary after adjustment of the dosing interval

Other Comments

Administration advice:
-Maintain adequate hydration

Parenteral:
-Administer via IV infusion over at least 1 hour; infused concentration should not exceed 7 mg per mL
-Do not administer by rapid or bolus IV injections; not for IM or subcutaneous injection

Oral:
-May take with or without food

Buccal tablet:
-Apply to upper gum just above the incisor tooth with a dry finger immediately after taking it out of the blister; hold in place for 30 seconds to ensure adhesion.
-For comfort, the rounded side should be placed to the gum (but either side can be placed)
-Tablet should be applied on the same side of the mouth as the herpes labialis symptoms.
-Tablet should stay in position and gradually dissolve throughout the day
-Buccal tablet should not be crushed, chewed, sucked, or swallowed
-Food and drink can be taken normally; avoid chewing gum, touching, pressing, or moving tablet
-If buccal tablet does not adhere or falls off within the first 6 hours; reposition immediately, if the tablet does not adhere, a new tablet should be placed
-If buccal tablet is swallowed within the first 6 hours, patient should be instructed to drink a glass of water and apply a new tablet
-If buccal tablet falls out or is swallowed after the first 6 hours, no need to reapply

Reconstitution/storage/preparation techniques:
-For IV infusion only; must be diluted prior to use
-Reconstitute with sterile water for injection (do not use bacteriostatic water for injection containing benzyl alcohol or parabens); use within 12 hours (refrigeration of reconstituted solution may result in the formation of a precipitate)
-Infusion concentrations must be 7 mg/mL or lower; once diluted, use within 24 hours

IV compatibility: Standard, commercially available electrolyte and glucose solutions are suitable for IV administration; biologic or colloidal fluids (e.g., blood products, protein solutions) are not recommended

General:
-Maximum dose of 20 mg/kg every 8 hours should not be exceeded
-Therapy should be initiated as early as possible following onset of symptoms.

Monitoring:
-Assess renal function prior to therapy

Patient advice:
-Patients should be advised to maintain adequate hydration during therapy.
-Patients should understand this drug is not a cure for genital herpes; proper precautions should be discussed and practiced to prevent transmission.

Response and Effectiveness

  • May take up to two hours to reach peak plasma concentrations after oral acyclovir administration.
  • May take up to three days for symptom reduction; however, acyclovir should be taken until the course prescribed is completed. Acyclovir works best when started within 48 hours of symptom onset.
  • In herpes zoster (shingles) infections, acyclovir shortened to time it took lesions to scab over and decreased the time needed for the rash to heal and become pain-free. Adults older than 50 gained the most benefit from taking acyclovir.
  • In varicella infections (chickenpox), acyclovir shortened the time to 50% healing, reduced the number of lesions and vesicles, and decreased rates of fever and tiredness by day 2.

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Before taking this medicine

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; or

  • a weak immune system (caused by disease or by using certain medicine).

Acyclovir is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

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.

What should I avoid while taking acyclovir?

Avoid brushing your teeth, chewing gum, or wearing an upper denture while you have a buccal tablet in your mouth. You may rinse your mouth gently. Drink plenty of liquids to prevent dry mouth.

Herpes infections are contagious and you can infect other people, even while you are being treated with acyclovir. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

Taking this medicine will not prevent you from passing genital herpes to your sexual partner. Avoid sexual intercourse while you have active lesions or the first symptoms of an outbreak. Genital herpes may still be contagious through "viral shedding" from your skin, even if you have no symptoms.

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