Formulary
Aciclovir: Indications, Dosing, Side Effects and Interactions
Aciclovir clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 11 min read
Aciclovir: Indications, Dosing, Side Effects and Interactions
Aciclovir clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Herpes simplex infection (local treatment)**
- **Adult** (To The Eye Using Eye Ointment): Apply 1 centimetre 5 times a day continue for at least 3 days after complete healing.
- **Adult** (To The Skin): Apply 5 times a day for 5-10 days, to be applied to lesions approximately every 4 hours, starting at first sign of attack.
**Herpes simplex, treatment (non-genital)**
- **Adult** (By Mouth): 200 mg 5 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete).
**Herpes simplex, treatment (non-genital) in immunocompromised or if absorption impaired**
- **Adult** (By Mouth): 400 mg 5 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete).
**Herpes simplex, treatment in encephalitis**
- **Adult** (By Intravenous Infusion): 10 mg/kg every 8 hours for at least 14 days (at least 21 days if also immunocompromised)-confirm cerebrospinal fluid negative for herpes simplex virus before stopping treatment.
**Herpes simplex, treatment in the immunocompromised**
- **Adult** (By Intravenous Infusion): 5 mg/kg every 8 hours usually for 5 days, alternatively 10 mg/kg every 8 hours usually for 5 days, higher dose to be used only if resistant organisms suspected.
**Herpes simplex, suppression**
- **Adult** (By Mouth): 400 mg twice daily, alternatively 200 mg 4 times a day; increased to 400 mg 3 times a day, dose may be increased if recurrences occur on standard suppressive therapy or for suppression of genital herpes during late pregnancy (from 36 weeks gestation).
**Herpes simplex, prophylaxis in the immunocompromised**
- **Adult** (By Mouth): 200-400 mg 4 times a day.
- **Adult** (By Intravenous Infusion): 5 mg/kg every 8 hours.
**Post-exposure prophylaxis of varicella zoster infection**
- **Adult** (By Mouth): 800 mg 4 times a day for 7 days, start course on day 7 after exposure; if the patient presents after this, the course may be started up to day 14 after exposure.
**Varicella zoster (chickenpox), treatment,Herpes zoster (shingles), treatment**
- **Adult** (By Mouth): 800 mg 5 times a day for 7 days.
- **Adult** (By Intravenous Infusion): 5 mg/kg every 8 hours usually for 5 days.
**Varicella zoster (chickenpox), treatment in encephalitis,Herpes zoster (shingles), treatment in encephalitis**
- **Adult** (By Intravenous Infusion): 10 mg/kg every 8 hours given for 10-14 days, possibly longer if also immunocompromised or if severe infection.
**Varicella zoster (chickenpox), treatment in immunocompromised**
- **Adult** (By Intravenous Infusion): 10 mg/kg every 8 hours usually for 5 days.
**Herpes zoster (shingles), treatment in immunocompromised**
- **Adult** (By Mouth): 800 mg 5 times a day continued for 2 days after crusting of lesions.
- **Adult** (By Intravenous Infusion): 10 mg/kg every 8 hours usually for 5 days.
**Genital herpes simplex, treatment of first episode**
- **Adult** (By Mouth): 200 mg 5 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete), alternatively 400 mg 3 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete).
**Genital herpes simplex, treatment of first episode, in immunocompromised or HIV-positive**
- **Adult** (By Mouth): 400 mg 5 times a day for 7-10 days (longer if new lesions appear during treatment or if healing incomplete).
**Severe genital herpes simplex, treatment, initial infection**
- **Adult** (By Intravenous Infusion): 5 mg/kg every 8 hours usually for 5 days, alternatively 10 mg/kg every 8 hours usually for 5 days, higher dose to be used only if resistant organisms suspected.
**Genital herpes simplex, treatment of recurrent infection**
- **Adult** (By Mouth): 800 mg 3 times a day for 2 days, alternatively 200 mg 5 times a day for 5 days, alternatively 400 mg 3 times a day for 3-5 days.
**Genital herpes simplex, treatment of recurrent infection in immunocompromised or HIV-positive patients**
- **Adult** (By Mouth): 400 mg 3 times a day for 5-10 days.
**Herpes simplex infection (local treatment) for aciclovir**
- **Child** (To the eye using eye ointment): Apply 1 centimetre 5 times a day continue for at least 3 days after complete healing.
- **Child** (To the skin): Apply 5 times a day for 5-10 days, to be applied to lesions approximately every 4 hours, starting at first sign of attack.
**Herpes simplex, treatment for aciclovir**
- **Child 1-23 months** (By mouth): 100 mg 5 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete).
- **Child 2-17 years** (By mouth): 200 mg 5 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete).
- **Neonate** (By intravenous infusion): 20 mg/kg every 8 hours for 14 days (for at least 21 days if CNS involvement-confirm cerebrospinal fluid negative for herpes simplex virus before stopping treatment).
- **Child 1-2 months** (By intravenous infusion): 20 mg/kg every 8 hours for 14 days (for at least 21 days if CNS involvement-confirm cerebrospinal fluid negative for herpes simplex virus before stopping treatment).
- **Child 3 months-11 years** (By intravenous infusion): 250 mg/m2 every 8 hours usually for 5 days.
- **Child 12-17 years** (By intravenous infusion): 5 mg/kg every 8 hours usually for 5 days.
**Herpes simplex, treatment, in immunocompromised or if absorption impaired for aciclovir**
- **Child 1-23 months** (By mouth): 200 mg 5 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete).
- **Child 2-17 years** (By mouth): 400 mg 5 times a day usually for 5 days (longer if new lesions appear during treatment or if healing incomplete).
**Herpes simplex, treatment, in immunocompromised or in simplex encephalitis for aciclovir**
- **Child 3 months-11 years** (By intravenous infusion): 500 mg/m2 every 8 hours usually for 5 days (given for at least 21 days in encephalitis-confirm cerebrospinal fluid negative for herpes simplex virus before stopping treatment).
- **Child 12-17 years** (By intravenous infusion): 10 mg/kg every 8 hours usually for 5 days (given for at least 14 days in encephalitis and for at least 21 days if also immunocompromised-confirm cerebrospinal fluid negative for herpes simplex virus before stopping treatment).
**Herpes simplex, suppression for aciclovir**
- **Child 12-17 years** (By mouth): 400 mg twice daily, alternatively 200 mg 4 times a day; increased to 400 mg 3 times a day, dose may be increased if recurrences occur on standard suppressive therapy or for suppression of genital herpes during late pregnancy (from 36 weeks gestation).
**Herpes simplex, prophylaxis in the immunocompromised for aciclovir**
- **Child 1-23 months** (By mouth): 100-200 mg 4 times a day.
- **Child 2-17 years** (By mouth): 200-400 mg 4 times a day.
**Post-exposure prophylaxis of varicella zoster infection [neonates exposed to maternal chickenpox 7 days before or after delivery] for aciclovir**
- **Neonate** (By intravenous infusion): 20 mg/kg every 8 hours for 21 days post-delivery, after a minimum of 48 hours, treatment can be converted to oral if preferred.
**Post-exposure prophylaxis of varicella zoster infection [neonates exposed to chickenpox or shingles other than in the mother in first 7 days of life] for aciclovir**
- **Neonate** (By mouth): 20 mg/kg 4 times a day for 14 days, start course on day 7 after exposure.
**Post-exposure prophylaxis of varicella zoster infection [infants who have remained in hospital since birth, or who require intensive or special care] for aciclovir**
- **Neonate** (By mouth): 20 mg/kg 4 times a day for 14 days, start course on day 7 after exposure.
- **Child 1-11 months** (By mouth): 10 mg/kg 4 times a day for 14 days, start course on day 7 after exposure.
**Post-exposure prophylaxis of varicella zoster infection for aciclovir**
- **Child 1-23 months** (By mouth): 10 mg/kg 4 times a day for 7 days, start course on day 7 after exposure; if the patient presents after this, the course may be started up to day 14 after exposure.
- **Child 2-11 years** (By mouth): 10 mg/kg 4 times a day for 7 days, start course on day 7 after exposure; if the patient presents after this, the course may be started up to day 14 after exposure.
- **Child 12-17 years** (By mouth): 10 mg/kg 4 times a day (max. per dose 800 mg) for 7 days, start course on day 7 after exposure; if the patient presents after this, the course may be started up to day 14 after exposure.
**Varicella zoster (chickenpox), treatment, Herpes zoster (shingles), treatment for aciclovir**
- **Child 1-23 months** (By mouth): 200 mg 4 times a day for 5 days.
- **Child 2-5 years** (By mouth): 400 mg 4 times a day for 5 days.
- **Child 6-11 years** (By mouth): 800 mg 4 times a day for 5 days.
- **Child 12-17 years** (By mouth): 800 mg 5 times a day for 7 days.
- **Neonate** (By intravenous infusion): 10-20 mg/kg every 8 hours for at least 7 days, higher end of dose range to be used if chickenpox develops despite prophylaxis with varicella-zoster immunoglobulin.
- **Child 1-2 months** (By intravenous infusion): 10-20 mg/kg every 8 hours for at least 7 days.
- **Child 3 months-11 years** (By intravenous infusion): 250 mg/m2 every 8 hours usually for 5 days.
- **Child 12-17 years** (By intravenous infusion): 5 mg/kg every 8 hours usually for 5 days.
**Varicella zoster (chickenpox), treatment in encephalitis, Herpes zoster (shingles), treatment in encephalitis for aciclovir**
- **Neonate** (By intravenous infusion): 10-20 mg/kg every 8 hours given for 10-14 days, possibly longer if also immunocompromised.
- **Child 1-2 months** (By intravenous infusion): 10-20 mg/kg every 8 hours given for 10-14 days, possibly longer if also immunocompromised.
- **Child 3 months-11 years** (By intravenous infusion): 500 mg/m2 every 8 hours given for 10-14 days, possibly longer if also immunocompromised.
- **Child 12-17 years** (By intravenous infusion): 10 mg/kg every 8 hours given for 10-14 days, possibly longer if also immunocompromised.
**Varicella zoster (chickenpox), treatment in immunocompromised for aciclovir**
- **Child 3 months-11 years** (By intravenous infusion): 500 mg/m2 every 8 hours usually for 5 days.
- **Child 12-17 years** (By intravenous infusion): 10 mg/kg every 8 hours usually for 5 days.
**Herpes zoster (shingles), treatment in immunocompromised for aciclovir**
- **Child 1-23 months** (By mouth): 200 mg 4 times a day continued for 2 days after crusting of lesions.
- **Child 2-5 years** (By mouth): 400 mg 4 times a day continued for 2 days after crusting of lesions.
- **Child 6-11 years** (By mouth): 800 mg 4 times a day continued for 2 days after crusting of lesions.
- **Child 12-17 years** (By mouth): 800 mg 5 times a day continued for 2 days after crusting of lesions.
- **Child 3 months-11 years** (By intravenous infusion): 500 mg/m2 every 8 hours usually for 5 days.
- **Child 12-17 years** (By intravenous infusion): 10 mg/kg every 8 hours usually for 5 days.
Cautions
With systemic use Elderly (risk of neurological reactions); maintain adequate hydration (especially with infusion or high doses) With topical use Avoid cream coming in to contact with eyes and mucous membranes
Side effects
Common or very common When used by eye (topical) Eye inflammation; eye pain With intravenous use Nausea; photosensitivity reaction; skin reactions; vomiting With oral use Abdominal pain; diarrhoea; dizziness; fatigue; fever; headache; nausea; photosensitivity reaction; skin reactions; vomiting Uncommon With intravenous use Anaemia; leucopenia; thrombocytopenia With topical use Skin reactions Rare or very rare With intravenous use Abdominal pain; agitation; angioedema; ataxia; coma; confusion; diarrhoea; dizziness; drowsiness; dysarthria; dyspnoea; encephalopathy; fatigue; fever; hallucination; headache; hepatic disorders; inflammation localised; psychosis; renal impairment; renal pain; seizure; tremor With oral use Agitation; anaemia; angioedema; ataxia; coma; confusion; drowsiness; dysarthria; dyspnoea; encephalopathy; hallucination; hepatic disorders; leucopenia; psychosis; renal impairment; renal pain; seizure; thrombocytopenia; tremor Frequency not known With intravenous use Crystalluria With oral use Alopecia; crystalluria
Interactions
**Other interactions (7):**
- Aciclovir is eliminated primarily unchanged in the urine via active renal tubular secretion.
- Any drugs administered concurrently that compete with this mechanism may increase aciclovir plasma concentrations.
- Probenecid and cimetidine increase the AUC of aciclovir by this mechanism, and reduce aciclovir renal clearance.
- Similarly increases in plasma AUCs of aciclovir and of the inactive metabolite of mycophenolate mofetil, an immunosuppresant agent used in transplant patients have been shown when the drugs are co...
- However no dosage adjustment is necessary because of the wide therapeutic index of aciclovir.
- An experimental study on five male subjects indicates that concomitant therapy with aciclovir increases AUC of totally administered theophylline with approximately 50%.
Pregnancy
With systemic use: Not known to be harmful-manufacturers advise use only when potential benefit outweighs risk. With topical use: Limited absorption from topical aciclovir preparations.
Breast feeding
With systemic use: Significant amount in milk after systemic administration-not known to be harmful but manufacturer advises caution.
Renal impairment
Prescribing in renal impairment . With systemic use: Risk of neurological reactions increased. Maintain adequate hydration (especially during renal impairment). Dose adjustments With systemic use: Consider dose reduction. With intravenous use: Use normal intravenous dose every 12 hours if eGFR 25-50 mL/minute/1.73 m 2 (every 24 hours if eGFR 10-25 mL/minute/1.73 m 2 ). Consult product literature for intravenous dose if eGFR less than 10 mL/minute/1.73 m 2 . With oral use: For herpes zoster , use normal oral dose every 8 hours if eGFR 10-25 mL/minute/1.73 m 2 (every 12 hours if eGFR less than 10 mL/minute/1.73 m 2 ). For herpes simplex , use normal oral dose every 12 hours if eGFR less than 10 mL/minute/1.73 m 2 .
Medicinal forms
Tablet,Tablet,Suspension,Solution,Solution,Ointment,Cream
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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