Acyclovir

IV Incompatibilities

Blood products and protein-containing solutions

Additive: Dobutamine, dopamine, meropenem (?)

Syringe: Caffeine

Y-site: Amifostine, amsacrine, aztreonam, cefepime, dobutamine, dopamine, fludarabine, foscarnet, gemcitabine, idarubicin, levofloxacin, morphine sulfate (?), ondansetron, piperacillin-tazobactam, sargramostim, vinorelbine

IV Compatibilities

Additive: Fluconazole

Y-site (partial list): Allopurinol, ampicillin, cefazolin, cimetidine, diphenhydramine, fluconazole, heparin, linezolid, lorazepam, magnesium sulfate, potassium chloride, propofol, trimethoprim-sulfamethoxazole, vancomycin

IV Preparation

Reconstitution: Concentrations >10 mg/mL increase risk of phlebitis; usually recommended not to exceed 7 mg/mL in D5W

IV Administration

Maximum dosage: 20 mg/kg q8hr

For IV infusion only

Avoid rapid infusion; infuse over 1 hour at constant rate to prevent renal damage

Maintain adequate hydration

Check for phlebitis, and rotate infusion sites

Storage

Reconstituted solutions remain stable for 24 hours at room temperature

To prevent precipitation, avoid refrigerating reconstituted solutions

Storage And Stability

ZOVIRAX® Tablets should be stored at controlled room temperature (15 to 25°C) in a dry place and protected from light.

ZOVIRAX® Suspension should be stored at controlled room temperature (15 to 25°C).

Dosage Forms, Composition And Packaging

Suspension: Each teaspoonful (5 mL) of ZOVIRAX® Suspension contains 200 mg acyclovir and the non-medicinal ingredients banana flavour, cellulose, glycerin, methylparaben, propylparaben, sorbitol, vanillin, and water.

Tablets: Each ZOVIRAX® 200 Tablet contains 200 mg acyclovir and the non-medicinal ingredients cellulose, indigotine, lactose, magnesium stearate, povidone, and sodium starch glycolate.

ZOVIRAX® Suspension is available in bottles of 125 mL* and 475 mL. Each teaspoonful (5 mL) of off-white, banana-flavoured suspension contains 200 mg acyclovir.

*125 mL bottle not available in Canada

ZOVIRAX® 200 Tablets are available in bottles of 100 tablets. Each blue, shield-shaped, bevel-edged, compressed tablet contains 200 mg acyclovir, and is imprinted with “ZOVIRAX” on one side and a triangle on the reverse.

GlaxoSmithKline Inc., 7333 Mississauga Road, Mississauga, Ontario, L5N 6L4 1-800-387-7374. Revised: November 10, 2014

For management of a suspected drug overdose, contact your regional Poison Control Centre.

Activated charcoal may be administered to aid in the removal of unabsorbed drug. General supportive measures are recommended.

Acyclovir is only partly absorbed in the gastrointestinal tract. Patients have ingested up to 20 g acyclovir on a single occasion, with no unexpected adverse effects. In clinical studies, the highest plasma concentration observed in a single patient at these doses was 10.0 μg/mL. Accidental, repeated overdoses of oral acyclovir over several days have been associated with gastrointestinal effects (such as nausea and vomiting) and neurological effects (headache and confusion).

Intravenous doses administered to humans have been as high as 1,200 mg/m² (28 mg/kg) 3 times daily for up to 2 weeks. Peak plasma concentrations have reached 80 μg/mL. Overdosage of intravenous acyclovir has resulted in elevations of serum creatinine, blood urea nitrogen and subsequent renal failure. Neurological effects including confusion, hallucinations, agitation, seizures and coma have been described in association with intravenous overdosage.

Patients should be observed closely for signs of toxicity. Hemodialysis significantly enhances the removal of acyclovir from the blood and may, therefore be considered a management option in the event of symptomatic overdose. Precipitation of acyclovir in renal tubules may occur if the solubility (2.5 mg/mL) in the intratubular fluid is exceeded. In the event of renal failure and anuria, the patient may benefit from hemodialysis until renal function is restored (see DOSAGE AND ADMINISTRATION).

Administration

Administer orally or by IV infusion.403 409

Parenteral preparation should not be administered orally or by IM or sub-Q injection and should not be applied topically or to the eye.409

Oral Administration

Administer without regard to meals.213 403

IV Infusion

For solution and drug compatibility information, see Compatibility under Stability.

Reconstitution

Reconstitute vial containing 500 mg or 1 g of acyclovir powder with 10 or 20 mL of sterile water for injection, respectively, to provide a solution containing 50 mg/mL.409

Shake well to ensure complete dissolution.409 Must be diluted further before IV administration.409

Dilution

For IV infusion, dilute concentrate containing acyclovir 25 or 50 mg/mL with a compatible IV solution (see Solution Compatibility under Stability) to a concentration of ≤7 mg/mL.409

Alternatively, dilute solutions reconstituted from powder prior to IV infusion with 50–125 mL of a compatible IV infusion solution.409 (See Solution Compatibility under Stability.) For fluid-restricted patients, dilute reconstituted solution in a ratio of approximately 1 part reconstituted solution to 9 parts infusion solution to a concentration of ≤7 mg/mL.409

Rate of Administration

Administer by IV infusion at a constant rate over at least 1 hour.409 Do not administer by rapid IV infusion (over <10 minutes) or rapid IV injection.409 (See Renal Effects under Cautions.)

Ensure adequate hydration.409

Dosage

Available as acyclovir and acyclovir sodium; dosage expressed in terms of acyclovir.409

Pediatric Patients

Mucocutaneous, Ocular, and Systemic Herpes Simplex Virus (HSV) Infections Treatment of Mucocutaneous HSV Infections Oral†

Immunocompromised children: 1 g daily given in 3–5 divided doses for 7–14 days.322

IV

Immunocompromised children <12 years of age: 10 mg/kg every 8 hours for 7–14 days.322 381 409

HIV-infected or immunocompromised adolescents and children ≥12 years of age: 5 mg/kg every 8 hours for 7–14 days.322 381 409 412 Alternatively, after lesions begin to regress, consider switching to oral acyclovir in a dosage of 400 mg 3 times daily and continue until lesions are completely healed.412

HSV Gingivostomatitis Oral†

HIV-infected children with mild, symptomatic gingivostomatitis: CDC and others recommend 20 mg/kg (up to 400 mg) 3 times daily for 7–14 days.413

Immunocompetent children: 15 mg/kg (up to 200 mg) 5 times daily for 7 days has been used in a few children 1–6 years of age.418

IV

HIV-infected children with moderate to severe gingivostomatitis: CDC and others recommend 5–10 mg/kg 3 times daily for 7–14 days.413 Consider chronic oral suppressive or maintenance therapy (secondary prophylaxis) in those with frequent or severe recurrences of gingivostomatitis.413

Chronic Suppressive or Maintenance Therapy (Secondary Prophylaxis) of HSV Infections† Oral

HIV-infected infants and children: 80 mg/kg daily (up to 1 g daily) in 3 or 4 divided doses.404

HIV-infected adolescents: 200 mg 3 times daily or 400 mg twice daily.404

Prophylaxis Against Recurrent Ocular HSV Disease† Oral

Children ≥12 years of age: 400 mg twice daily.408 419 AAP recommends 80 mg/kg daily (up to 1 g daily) given in 3 divided doses.322

Optimum duration of prophylaxis unclear;419 has been continued for 12–18 months in clinical studies.408 419

Treatment of HSV Encephalitis or Disseminated Disease IV

Immunocompromised children: 20 mg/kg every 8 hours in those 3 months to 12 years of age381 409 and 10–15 mg/kg every 8 hours in those ≥12 years of age.211 246 322 409 413 Manufacturer recommends a treatment duration of 10 days,409 but AAP and others recommend 14–21 days for disseminated or CNS infections.235 236 311 322 381 413

HIV-infected children: CDC and others recommend 10 mg/kg or 500 mg/m2 3 times daily for 21 days.413

HIV-infected adolescents: CDC and others recommend 10 mg/kg 3 times daily for 14–21 days.412

Treatment of Neonatal HSV Infections IV

Neonates and children ≤3 months of age: Manufacturer recommends 10 mg/kg every 8 hours for 10 days.409

Neonates and children ≤3 months of age: AAP recommends 20 mg/kg every 8 hours given for 14 days for infections of skin, eyes, or mouth or 21 days for disseminated or CNS infections.322

HIV-infected or -exposed neonates: CDC and others recommend 20 mg/kg 3 times daily given for 14 days for infections of skin, eyes, or mouth or 21 days for disseminated or CNS infections.413

Prevention of HSV Recurrence in Hematopoietic Stem Cell Transplant (HSCT) Recipients† Oral

HSV-seropositive children: 0.6–1 g daily given in 3–5 divided doses.414

HSV-seropositive adolescents: 200 mg 3 times daily.414

Initiate prophylaxis at beginning of conditioning therapy and continue until engraftment or until mucositis resolves (approximately 30 days after allogeneic HSCT).414 Routine prophylaxis for >30 days after HSCT not recommended.414

IV

HSV-seropositive children: 250 mg/m2 every 8 hours or 125 mg/m2 every 6 hours.414

HSV-seropositive adolescents: 250 mg/m2 every 12 hours.

Initiate prophylaxis at beginning of conditioning therapy and continue until engraftment or until mucositis resolves (approximately 30 days after allogeneic HSCT).414 Routine prophylaxis for >30 days after HSCT not recommended.414

Genital Herpes Treatment of First Episodes Oral

Children: AAP recommends 40–80 mg/kg daily (maximum 1 g daily) given in 3 or 4 divided doses for 5–10 days.322

Adolescents: CDC recommends 400 mg 3 times daily or 200 mg 5 times daily for 7–10 days;244 duration may be extended if healing is incomplete after 10 days.244

HIV-infected adolescents: CDC and others recommend 20 mg/kg (up to 400 mg) or 400 mg 3 times daily for 7–14 days.412

IV

Adolescents and children ≥12 years of age with severe initial episodes: 5–10 mg/kg every 8 hours.244 381 409 410

Manufacturer and some clinicians recommend 5–7 days of IV acyclovir;381 409 CDC states IV acyclovir should be given for 2–7 days or until clinical improvement occurs, followed by an oral antiviral to complete at least 10 days of treatment.244

Episodic Treatment of Recurrent Episodes Oral

Adolescents: CDC recommends 400 mg 3 times daily for 5 days, 800 mg twice daily for 5 days, or 800 mg 3 times daily for 2 days.244

HIV-infected adolescents: CDC recommends 400 mg 3 times daily for 5–10 days.244 Alternatively, acyclovir can be given for 7–14 days.412

Initiate episodic therapy at the earliest prodromal sign or symptom of recurrence or within 1 day of the onset of lesions.244 403

Chronic Suppression of Recurrent Episodes Oral

Adolescents: CDC recommends 400 mg twice daily.244

HIV-infected adolescents: CDC recommends 400–800 mg 2 or 3 times daily.244

Discontinue periodically (e.g., after 12 months or once yearly) to reassess need for continued therapy.244 403

Varicella-Zoster Infections Treatment of Varicella (Chickenpox) Oral

Immunocompetent children ≥2 years of age: Manufacturer recommends 20 mg/kg 4 times daily (maximum 80 mg/kg daily) for 5 days in those weighing ≤40 kg and 800 mg 4 times daily for 5 days in those weighing >40 kg.403 Alternatively, some clinicians recommend 20 mg/kg (up to 800 mg) 4 times daily for 5 days.239 322 329 331 336 368 381 410

HIV-infected children with mild immunosuppression and mild varicella: CDC and others recommend 20 mg/kg (up to 800 mg) 4 times daily for 7 days or until no new lesions have appeared for 48 hours.413

Initiate therapy at the earliest sign or symptom of infection (within 24 hours of onset of rash).368 403

IV

Immunocompromised children: AAP recommends 10 mg/kg 3 times daily for 7–10 days for those <1 year of age and 500 mg/m2 3 times daily for 7–10 days in those ≥1 year of age.322

Immunocompromised adolescents and children: Some clinicians recommend 20 mg/kg every 8 hours for 7–10 days in those ≤12 years of age and 10 mg/kg every 8 hours for 7 days in those >12 years of age.381

HIV-infected children with moderate or severe immunosuppression and varicella associated with high fever or necrotic lesions: CDC and others recommend 10 mg/kg 3 times daily for 7 days or until no new lesions have appeared for 48 hours.413 Alternatively, a dosage of 500 mg/m2 every 8 hours has been suggested for those ≥1 year of age.413

HIV-infected adolescents: CDC and others recommend 10 mg/kg every 8 hours for 7–10 days.412 After defervescence and if there is no evidence of visceral involvement, switch to oral acyclovir in a dosage of 800 mg 4 times daily.412

Treatment of Herpes Zoster (Shingles, Zoster) Oral

Immunocompetent children ≥12 years of age: 800 mg every 4 hours 5 times daily (4 g daily) for 5–10 days.261 284 285 309 322 381 403 410

HIV-infected children with mild immunosuppression and mild varicella: CDC and others recommend 20 mg/kg (up to 800 mg) 4 times daily for 7–10 days.413

Initiate therapy preferably within 48 hours of onset of rash.261 284 285 309 322 381 403 410

IV

Immunocompetent children: AAP recommends 10 mg/kg 3 times daily for 7–10 days for those <1 year of age and 500 mg/m2 3 times daily for 7–10 days in those ≥1 year of age.322

Immunocompromised children: 20 mg/kg every 8 hours for 7–10 days in those <12 years of age381 322 409 413 and 10 mg/kg every 8 hours for 7 days in those ≥12 years of age.381 409 410

HIV-infected children with severe immunosuppression and extensive multidermatomal zoster or zoster with trigeminal nerve involvement: CDC and others recommend 10 mg/kg 3 times daily for 7–10 days.413

HIV-infected adolescents: CDC and others recommend 10 mg/kg every 8 hours until cutaneous and visceral disease resolves.412

Adults

Mucocutaneous, Ocular, and Systemic Herpes Simplex Virus (HSV) Infections Treatment of Mucocutaneous HSV Infections Oral†

Immunocompromised or HIV-infected adults: 400 mg every 4 hours while awake (5 times daily) for 7–14 days.381 410

IV

Immunocompromised or HIV-infected adults: CDC and others recommend 5 mg/kg every 8 hours for 7–14 days.381 409 412 Alternatively, after lesions begin to regress, consider switching to oral acyclovir in a dosage of 400 mg 3 times daily and continue until lesions are completely healed.412

Chronic Suppressive or Maintenance Therapy (Secondary Prophylaxis) of HSV Infections† Oral

HIV-infected adults: 200 mg 3 times daily or 400 mg twice daily.404

Treatment of Orolabial HSV Infections Oral

400 mg 5 times daily for 5 days.381

HIV-infected adults: CDC and others recommend 400 mg 3 times daily for 7–14 days.381 412

Treatment of HSV Keratitis† Oral

HIV-infected adults: 400 mg 5 times daily.407 Long-term therapy may be required to prevent recurrence.407

Prophylaxis Against Recurrent Ocular HSV Disease† Oral

Immunocompetent adults: 400 mg twice daily.408 419 420 Optimum duration of prophylaxis unclear;419 has been continued for 12–18 months in clinical studies.408 419

Treatment of HSV Encephalitis or Disseminated Disease IV

10–15 mg/kg every 8 hours.211 246 322 381 409 412 Manufacturer recommends a treatment duration of 10 days,409 but CDC and others recommend 14–21 days for disseminated or CNS infections.235 236 311 381 412

HIV-infected adults: CDC and others recommend 10 mg/kg 3 times daily for 14–21 days.412

Prevention of HSV Recurrence in Hematopoietic Stem Cell Transplant (HSCT) Recipients† Oral

HSV-seropositive adults: 200 mg 3 times daily initiated at beginning of conditioning therapy and continued until engraftment or until mucositis resolves (i.e., approximately 30 days after allogeneic HSCT).414 Routine prophylaxis for >30 days after HSCT not recommended.414

IV

HSV-seropositive adults: 250 mg/m2 every 12 hours initiated at beginning of conditioning therapy and continued until engraftment or until mucositis resolves (i.e., approximately 30 days after allogeneic HSCT).414 Routine prophylaxis for >30 days after HSCT not recommended.414

Genital Herpes Treatment of First Episodes Oral

Manufacturer recommends 200 mg every 4 hours while awake (5 times daily) for 10 days.403

CDC and others recommend 400 mg 3 times daily or 200 mg 5 times daily for 7–10 days;244 313 381 410 duration may be extended if healing is incomplete after 10 days.244

HIV-infected adults: CDC and others recommend 400 mg 3 times daily for 7–14 days.412

IV

Adults with severe initial episodes: 5–10 mg/kg every 8 hours.244 313 381 409 410

Manufacturer and some clinicians recommend 5–7 days of IV acyclovir;313 381 409 CDC states IV acyclovir should be given for 2–7 days or until clinical improvement occurs, followed by an oral antiviral to complete at least 10 days of therapy.244

Treatment of First Episode of Herpes Proctitis† Oral

400 mg 5 times daily for 10 days or until clinical resolution occurs.305

Episodic Treatment of Recurrent Episodes of Genital Herpes Oral

Manufacturer recommends 200 mg every 4 hours while awake (5 times daily) for 5 days.403

CDC recommends 400 mg 3 times daily for 5 days, 800 mg twice daily for 5 days, or 800 mg 3 times daily for 2 days.244

HIV-infected adults: CDC recommends 400 mg 3 times daily for 5–10 days.244 Alternatively, acyclovir can be given for 7–14 days.412

Initiate episodic therapy at the earliest prodromal sign or symptom of recurrence or within 1 day of the onset of lesions.244 403 410

Chronic Suppression of Recurrent Episodes of Genital Herpes Oral

400 mg twice daily;244 313 381 403 alternatively, 200 mg 3–5 times daily.403

HIV-infected adults: 400–800 mg 2 or 3 times daily.244

Discontinue periodically (e.g., after 12 months or once yearly) to reassess need for continued therapy.244 403

Varicella-Zoster Infections Treatment of Varicella (Chickenpox) Oral

20 mg/kg (up to 800 mg) 4 times daily for 5 days.239 322 329 331 336 353 368 381 403 410 412

Initiate therapy at the earliest sign or symptom of infection (within 24 hours of onset of rash).368 403

IV, then Oral

HIV-infected or immunocompromised adults: CDC and others recommend 10 mg/kg every 8 hours for 7–10 days.381 412 After defervescence and if there is no evidence of visceral involvement, switch to oral acyclovir in a dosage of 800 mg 4 times daily.412

Treatment of Herpes Zoster (Shingles, Zoster) Oral

800 mg every 4 hours (5 times daily) for 7–10 days.261 284 285 309 322 381 403 410

Initiate therapy preferably within 48 hours of onset of rash.261 284 285 309 322 381 410

IV

HIV-infected or immunocompromised adults: CDC and others recommend 10 mg/kg every 8 hours for 7 days or until cutaneous and visceral disease resolves.381 409 410 412

Treatment of Herpes Zoster Ophthalmicus† Oral

Immunocompetent adults: 600 mg every 4 hours 5 times daily (3 g daily) for 10 days.281 282 286

Initiate therapy within 72 hours (but no later than 7 days) after rash onset.281 282 286

IV, then Oral

HIV-infected adults: 10 mg/kg IV 3 times daily for 7 days followed by 800 mg orally 3–5 times daily has been used.407

Treatment of Dermatomal Herpes Zoster† Oral

Immunocompromised adults: 800 mg 5 times daily for 10 days has been used,219 225 but CDC and others recommend oral famciclovir or valacyclovir for localized dermal infections in HIV-infected individuals.412

Prescribing Limits

Pediatric Patients

Oral

Maximum 20 mg/kg 4 times daily (1 g daily)322 403 in children ≥2 years of age weighing ≤40 kg.403

IV

Maximum 20 mg/kg every 8 hours.409

Adults

Oral

800 mg per dose.239 322 329 331 336 353 368 381 410

IV

Maximum 20 mg/kg every 8 hours.409

Special Populations

Renal Impairment

Adjustment of Usual Oral Dosage Oral Dosage in Renal Impairment403

Usual Dosage Regimen	Clcr (mL/min per 1.73 m2)	Adjusted Dosage Regimen
200 mg every 4 h 5 times daily	>10	No adjustment necessary
	0–10	200 mg every 12 h
400 mg every 12 h	>10	No adjustment necessary
	0–10	200 mg every 12 h
800 mg every 4 h 5 times daily	>25	No adjustment necessary
	10–25	800 mg every 8 h
	0–10	800 mg every 12 h

Hemodialysis

Give supplemental oral dose immediately after each dialysis period.403

Peritoneal Dialysis

Supplemental doses do not appear necessary.403

Adjustment of Usual IV Dosage IV Dosage in Renal Impairment409

Clcr (mL/min per 1.73 m2)	Percent of Recommended Dose	Dosing Interval (hours)
>50	100%	8
25–50	100%	12
10–25	100%	24
0–10	50%	24

Hemodialysis

Adjust dosing schedule so that a supplemental IV dose is administered immediately after each dialysis period.409

CAPD

Supplemental doses do not appear necessary.316

Alternative IV Dosage Regimens for End-Stage Renal Disease

93–185 mg/m2 as a loading dose, followed by a maintenance dosage of 35–70 mg/m2 every 8 hours, and 56–185 mg/m2 immediately after dialysis.a

250–500 mg/m2 as a loading dose, followed by a maintenance dosage of 250–500 mg/m2 every 48 hours, and 150–500 mg/m2 immediately after dialysis.a

2.5 mg/kg every 24 hours and 2.5 mg/kg after each dialysis period.a

HIV-infected Patients with Impaired Renal Function (Oral Administration) Oral Dosage for HIV-infected Patients with Impaired Renal Function (Based on Usual Dosage of 200–800 mg Every 4–6 Hours)411

Clcr (mL/min per 1.73 m2)	Adjusted Dosage Regimen
>80	No adjustment necessary
50–80	200–800 mg every 6–8 h
25–50	200–800 mg every 8–12 h
10–25	200–800 mg every 12–24 h
<10	200–400 mg every 24 h

Hemodialysis

Give supplemental usual oral dose after each dialysis period.411

HIV-infected Patients with Impaired Renal Function (IV Administration) IV Dosage for HIV-infected Patients with Impaired Renal Function (Based on Usual Dosage of 5 mg/kg Every 8 hours)409411

Clcr (mL/min per 1.73 m2)	Adjusted Dosage Regimen
>80	No adjustment necessary
50–80	No adjustment necessary
25–50	5 mg/kg every 12–24 hours
10–25	5 mg/kg every 12–24 hours
<10	2.5 mg/kg every 24 hours

Hemodialysis

Adjust dosing schedule so that daily IV dose is given after hemodialysis on dialysis days.411

Geriatric Patients

Cautious dosage selection; reduced dosage may be needed because of age-related decreases in renal function.403 409 (See Geriatric Use under Cautions.)

Obese Patients

Use ideal body weight to determine IV dosage.409

Absorption

Bioavailability

Absorption from GI tract is variable and incomplete; 10–30% of an oral dose may be absorbed.213 233 403 Peak plasma concentrations usually are attained within 1.5–2.5 hours after oral administration.213 232

Commercially available capsules and oral suspension are bioequivalent.403

Food

Food does not appear to affect GI absorption.213 403

Distribution

Extent

Widely distributed into body tissues and fluids including the brain, kidney, saliva, lung, liver, muscle, spleen, uterus, vaginal mucosa, CSF, herpetic vesicular fluid, and semen.266 a

Following IV administration in patients with uninflamed meninges, CSF concentrations of the drug are about 50% of concurrent serum concentrations.a

Crosses placenta following oral or IV administration;245 421 cord blood concentrations may be higher than maternal plasma concentrations.421

Distributed into milk following oral or IV administration; milk concentrations may be higher than concurrent maternal plasma concentrations.251 308 421

Plasma Protein Binding

9–33%.403 409

Elimination

Metabolism

Metabolized partially to 9-carboxymethoxymethylguanine;a also converted intracellularly in cells infected with herpesviruses to acyclovir triphosphate, the pharmacologically active form of the drug.354 403

Elimination Route

Excreted principally in urine as unchanged drug.a

Half-life

Adults with normal renal function: initial serum half-life averages 0.34 hour and terminal half-life averages 2.1–3.5 hours.a

Children >1 year of age: elimination half-life similar to that in adults.a

Neonates: half-life depends principally on maturity of renal mechanisms for clearance.a

Special Populations

Renal impairment may reduce clearance.a

Storage

Oral

Capsules and Tablets

Tight, light-resistant containers at 15–25°C.403

Suspension

15–25°C.403

Parenteral

Powder for IV Infusion

15–25°C.409 Use reconstituted solution within 12 hours.409 Refrigeration of this solution may cause a precipitate, which will redissolve at room temperature.409 Following dilution with infusion solution, use drug within 24 hours.409

Compatibility

For information on systemic interactions resulting from concomitant use, see Interactions.

Parenteral

Solution Compatibility

Bacteriostatic water for injection containing parabens should not be used to reconstitute acyclovir sodium powder; precipitation may occur.424

When diluted with >10% dextrose, a yellow discoloration may appear but does not affect potency.a

Compatible424
Dextrose 5% and sodium chloride 0.2, 0.45, or 0.9%
Dextrose 5%
Lactated Ringer’s
Sodium chloride 0.9%

Drug Compatibility Admixture Compatibility424

Compatible
Fluconazole
Incompatible
Dobutamine HCl
Dopamine HCl
Variable
Meropenem

Y-site Injection Compatibility424

Compatible
Allopurinol sodium
Amikacin sulfate
Amphotericin B cholesteryl sulfate complex
Ampicillin sodium
Cefamandole nafate
Cefazolin sodium
Cefoperazone sodium
Cefotaxime sodium
Cefoxitin sodium
Ceftazidime
Ceftizoxime sodium
Ceftriaxone sodium
Cefuroxime sodium
Chloramphenicol sodium succinate
Cimetidine HCl
Clindamycin phosphate
Dexamethasone sodium phosphate
Dimenhydrinate
Diphenhydramine HCl
Docetaxel
Doxorubicin HCl liposome injection
Doxycycline hyclate
Erythromycin lactobionate
Etoposide phosphate
Famotidine
Filgrastim
Fluconazole
Gatifloxacin
Gentamicin sulfate
Granisetron HCl
Heparin sodium
Hydrocortisone sodium succinate
Hydromorphone HCl
Imipenem–cilastatin sodium
Linezolid
Lorazepam
Magnesium sulfate
Melphalan HCl
Methylprednisolone sodium succinate
Metoclopramide HCl
Metronidazole
Milrinone lactate
Multivitamins
Nafcillin sodium
Oxacillin sodium
Paclitaxel
Penicillin G potassium
Pentobarbital sodium
Perphenazine
Piperacillin sodium
Potassium chloride
Propofol
Ranitidine HCl
Remifentanil HCl
Sodium bicarbonate
Tacrolimus
Teniposide
Theophylline
Thiotepa
Ticarcillin disodium
Tobramycin sulfate
Trimethoprim–sulfamethoxazole
Vancomycin HCl
Zidovudine
Incompatible
Amifostine
Amsacrine
Aztreonam
Cefepime HCl
Dobutamine HCl
Dopamine HCl
Fludarabine phosphate
Foscarnet sodium
Gemcitabine HCl
Idarubicin HCl
Levofloxacin
Ondansetron HCl
Piperacillin sodium–tazobactam sodium
Sargramostim
Tacrolimus
Vinorelbine tartrate
Variable
Cisatracurium besylate
Diltiazem HCl
Meperidine HCl
Meropenem
Morphine sulfate

• Advise patients that acyclovir is not a cure for genital herpes and there are no data evaluating whether acyclovir prevents transmission of genital herpes to others.244

• Importance of avoiding sexual contact with uninfected partners when genital lesions or prodromal symptoms are present, since there is a risk of infecting sexual partners.244 Genital herpes can be transmitted in the absence of symptoms.244

• Importance of initiating treatment as soon as possible following onset of signs and symptoms.403 409

• Advise patients receiving chronic suppressive therapy of the need for periodic reassessment of the continued need for acyclovir therapy.244 403

• Importance of not exceeding the recommended dosage and duration of therapy.409

• Importance of maintaining adequate hydration during treatment.403 409

• Importance of contacting clinician if severe or troublesome adverse effects occur.403

• Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs.403 409

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.403

• Importance of advising patients of other important precautionary information. (See Cautions.)

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.

Take acyclovir for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated.

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

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.

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.

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

Comments:
-Therapy should be initiated at the earliest sign or symptom of chickenpox; there is no information of efficacy when initiated more than 24 hours after onset of symptoms.
-According to the Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents, oral acyclovir therapy should be considered alternative therapy for the treatment of uncomplicated cases of chickenpox; IV acyclovir is the preferred therapy for severe or complicated cases.

Use: For the treatment of chickenpox (varicella).

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)

Comments:
-Acyclovir is the oral drug of choice for treating herpes zoster in HIV-infected children; it should be given for 7 to 10 days, although longer durations should be considered if lesions are slow to resolve.
-Initial IV therapy is recommended in children with more severe immunosuppression.
-According to the Guidelines for the Prevention and Treatment of Opportunistic Infections, oral acyclovir therapy in adolescents should be considered alternative therapy for the treatment of uncomplicated cases of herpes zoster; IV acyclovir is preferred therapy for extensive cutaneous lesion or visceral involvement.
-Guidelines for the Prevention and Treatment of Opportunistic Infections Among HIV- Exposed and HIV-Infected Children and HIV- Infected Adults and Adolescents may be consulted for additional guidance.

Use: For the acute treatment of herpes zoster (shingles).

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).

Oral:
For CrCl 0 to 10 mL/min/1.73 m2:
-If normal dose is 200 mg orally every 4 hours 5 times a day: Reduce dose to 200 mg orally every 12 hours
-If normal dose is 400 mg orally every 12 hours: Reduce dose to 200 mg orally every 12 hours
-If normal dose is 800 mg orally every 4 hours 5 times a day: Reduce dose to 800 mg orally every 12 hours

For CrCl 10 to 25 mL/min/1.73 m2:
-If normal dose is 800 mg orally every 4 hours 5 times a day: Reduce dose to 800 mg orally every 8 hours

IV:
For CrCl 0 to 10 mL/min/1.73 m2: Give 50% of dose every 24 hours
For CrCl 10 to 25 mL/min/1.73 m2: Give 100% of dose every 24 hours
For CrCl 25 to 50 mL/min/1.73 m2: Give 100% of dose every 12 hours
For CrCl greater than 50 mL/min/1.73 m2: Give 100% of dose every 8 hours

Acyclovir is an antiviral drug that helps treat chickenpox, genital herpes, and shingles infections. It is most effective when started within 48 hours of symptom onset.

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.