Acyclovir Dosing for Adults

Indication		NAG, 2019	Stanford Antibiotics Guideline , 2019	Uptodate
Varicella zoster (Chicken Pox)	Immuno- compromised	IV : 10mg/kg/dose q8h for 7 days (change to oral once there is an improvement) Advisable to start treatment early within 48 hours	IV : 10-12mg/kg/dose (500mg/M2)q8h for 7 days	Severe or complicated infection IV : 10 mg/kg/dose q8h for 7 -10 days ; some experts recommend up to 15 mg/kg/dose q8h May switch to oral antiviral after defervescence if no evidence of visceral involvement; continue until all lesions have crusted Uncomplicated infection Oral: 800 mg 5x/day for 5 - 7 days; some experts recommend a minimum duration of 7 days, extending the course until all lesions have crusted Initiate within 24 hours of symptom onset, may  start later if patient still has active lesion
	Immuno- competent	PO : 800mg 5x/day for 7 days Advisable to start treatment early within 48 hours	PO : 800mg 5x/day for 5-7 days Initiate within 24 hours of rash	PO: 800 mg 5x/day for ≥5 - 7 days and until all lesions have crusted Initiate within 24 hours of symptom onset, may start later if patient still has active lesion
Herpes zoster (Shingles)	Immuno- compromised	Refer varicella zoster treatment Systemic antiviral treatment is recommended to all immunocompromised patient or for immunocompetent patients with the following criteria. 1.          >50 years 2.          Have moderate or severe pain 3.          Have moderate or severe rash 4.          Have have non truncal involvement Advisable to start treatment early within 48-72 hours	Antiviral is indicated for patient fulfilling any of this criteria. 1.          >50 years 2.          Moderate to severe rash or pain 3.          Involvement of face/eye 4.          Acute complication of infection 5.          Immunocompromised state Mild - Moderate PO: 800 mg 5x/day for 7 days Severe (patient with ocular or neurologic or disseminated disease)    IV: 10 to 15 mg/kg/dose q8h 7-14 days 7 days duration is reasonable in immunocompromised patient , some experts continue until crusting of all lesion. Benefit of antiviral therapy in immunocompetent hosts >72 hours of symptoms is less clear. Treatment is recommended for immunocompromised patients at any time with active infection.	Acute localized dermatomal PO: 800 mg 5x/day for 7 - 10 days; consider longer duration if lesions resolve slowly Extensive cutaneous lesions or visceral involvement  IV: 10 to 15 mg/kg/dose q8h When formation of new lesions has ceased and signs/symptoms of visceral infection are improving, switch to an oral antiviral to complete a total of 10 to 14 days of therapy
	Immuno- competent			PO: 800 mg 5x/day for 7 days Initiate at earliest sign or symptom; treatment is most effective when initiated ≤72 hours after rash onset, but may initiate treatment >72 hours after rash onset if new lesions are continuing to appear
Viral Encephalitis Herpes simplex Varicella zoster		IV : 10mg/kg/dose q8h for 14-21 days Consider using Ideal Body Weight for obese patient	IV : 10-12.5 mg/kg/dose q8h for 14-21 days Dose calculation in obese patient undertain Higher doses up to 15mg/kg/dose q8h have been used ion adults but with little additional benefit	IV: 10 mg/kg/dose q8h Duration for encephalitis is 14 to 21 days and for meningitis is 10 to 14 days Treatment of encephalitis requires IV therapy while treatment of meningitis may include step-down oral antiviral therapy
Herpes simplex (Genital)	1) Initial Episode A)        Immuno- compromised	PO : 400mg q8h for 5 days Only indicated within 5 days of start of new episode and while new lesions are forming	PO: 400mg q8h for 7-10 days For severe cases IV : 5mg/kg/dose q8h for 5-7 days	Oral: 400 mg q8h  for 5 - 10 days; extend treatment duration if lesions have not healed completely after 10 days For severe disease IV : 5 to 10 mg/kg/dose q8h for 2 - 7 days, followed by oral acyclovir (or similar antiviral) once lesions begin to regress and continue for ≥10 days of therapy and until complete resolution
	b) Immuno- competent			PO : 400 mg q8h  or  200 mg 5x/day for 7 - 10 days; extend duration if lesions have not healed completely after 10 days For severe disease IV : 5 to 10 mg/kg/dose q8h for 2 - 7 days, followed by oral acyclovir (or similar antiviral) to complete ≥10 days of therapy total
	2) Recurrent a ) Immuno- compromised	Short course PO : 800mg q8h for 2 days 5-days regimen PO : 400mg q8h Only indicated within 5 days of start of new episode and while new lesions are forming	PO : 400mg q8h for 5-10 days	Oral: 400 mg q8h  for 5 - 10 days; extend treatment duration if lesions have not healed completely after 10 days For severe disease IV : 5 to 10 mg/kg/dose q8h for 2 - 7 days, followed by oral acyclovir (or similar antiviral) once lesions begin to regress and continue for ≥10 days of therapy and until complete resolution
	b) Immuno- competent		PO : 800mg q8h x 2 days or 400mg q8h x 5 days	Oral: 400 mg q8h for 5 days or  800 mg q12h for 5 days or      800 mg q8h for 2 days Treatment is most effective when initiated during the prodrome or within 1 day of lesion onset
	3) Supressive therapy a)         Immuno-compromised	Indicated if ≥ 6 recurrences per year, severe, prolonged or with psychosocial problems PO : 400mg q12h Duration up to 1 year then reassess If breakthrough recurrences occur, dosage should be increased , refer recurrent episode	PO : 400-800mg q8-12h	Indicated for severe and/or frequent recurrences PO: 400 - 800 mg q8-12h Reassess need periodically (eg, annually)
	b)        Immuno- competent		PO : 400mg q12h	Indicated for severe and/or frequent recurrences PO: 400 mg q12h Reassess need periodically (eg, annually)
	4) Pregnancy          (First episode)	PO : 400 mg q8h for 5 days If during third trimester, continue suppresive PO Acyclovir 400mg q8h until delivery	Not mentioned	PO : 400 mg q8h for 7 - 10 days; extend treatment duration if lesion has not healed completely after 10 days
	5) Pregnancy ( Recurrent)	Not mentioned		PO: 400 mg q8h  or 800 mg q12h for 5 days Some experts reserve treatment of recurrent episodes for patients with severe and/or frequent symptom
	6) Pregnancy ( Suppressive )	PO : 400 mg q8h Treatment recommended starting at 36 weeks of gestation until delivery		PO: 400 mg q8h, beginning at 36 weeks' gestation and continued until the onset of labor Some experts offer suppressive therapy earlier than 36 weeks' gestation for women who have a first-episode lesion during the third trimester
Herpes simplex (Mouth, lips: Oral lesion)		Symptomatic treatment in most cases May consider 1.          Topical : Acyclovir 5% q4h for 5-10 days in prodromal phase in recurrent herpes labialis 2.          Systemic antiviral : PO 400-800mg 5x/day for 7-14 days	PO : 400 mg 5x/day for (q4h while awake) x 5 days Topical: Acyclovir 5% 6x/day (q3h) x 7 days Start treatment with prodrome symptoms (tingling/burning) before lesions appear	Topical : 1/2” ribbon of ointment for a 4” square surface area q3h (6 times daily) for 7 days Treatment, initial or recurrent episode: Oral: 400 mg q8h for 5 - 10 days and until complete lesion resolution in immunocompromised patients IV: 5 mg/kg/dose q8h for severe disease in immunocompromised patients; switch to oral acyclovir (or similar antiviral) once lesions begin to regress and continue until complete resolution Suppressive therapy (eg, for severe and/or frequent recurrences) Oral: 400 mg q12h Reassess need periodically (eg, annually)
Herpes simplex esophagitis		PO : 400mg q8h for 5 days	Not mentioned	Immunocompetent patients PO :  400 mg q8h or  200 mg 5x/day for 7 to 10 days Patients with severe odynophagia or dysphagia IV: 5 mg/kg/dose q8h; patients who rapidly improve can be switched to an oral antiviral to complete a total of 7 to 14 days of therapy
Herpes simplex keratitis		LA Acyclovir 3% 5x/day In presence of stromal or endothelial disease PO: 400mg 5x/day for 7-14 days Prophylaxis for recurrent PO : 400mg q12h x 12 months	LA Acyclovir 3% 5x/day PO: 400mg 5x/day for 7-14 days Prophylaxis for recurrent PO : 400mg q12h x 12 months	Topical : Apply a ½-inch ribbon of ointment in the lower cul-de-sac of the affected eye(s) 5 times daily (approximately every 3 hours while awake) until the corneal ulcer heals, then apply a ½-inch ribbon 3 times daily for 7 days PO: 400mg 5x/day
Herpes zoster ophtalmicus		Mild infection PO : 400 mg q8h for 5 days Severe life threatening IV : 5-10mg/kg/dose q8h for 5 days or until to talke orally	Not mentioned	Immunocompromised patients or patients who require hospitalization for sight-threatening disease IV: 10 mg/kg/dose q8h for 7 days
Acute Retinal Necrosis		IV : 10mg/kg/dose q8h for 10-14 days Followed by PO: 800mg 5x/day for 6 weeks	IV : 10-12mg/kg q8h for 7-10 days until disease stabilize then oral therapy for a minimum 6 weeks with valacyclovir or famciclovir	IV: 10 - 15 mg/kg/dose q8h for 10 to 14 days, followed by ~6 weeks of valacyclovir in HIV-infected patients, intravitreal ganciclovir should be added
Viral pneumonia		IV : Acyclovir 10mg/kg/dose q8h x 7 days	Not mentioned	Not mentioned

Compiled by N. Nabiha [ 02 May 2020 ]