Tuesday, May 5, 2020

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 ]

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