Drugs List

Therapeutic Indications

Uses

Herpes encephalitis
Herpes simplex viral (HSV) infection -immunocompromised
Herpes simplex virus (HSV) infection - prophylaxis (in immunocompromised)
Herpes simplex virus (HSV) infection - severe initial genital herpes
Herpes simplex virus infection in the immunocompetent: treatment
Herpes zoster infection in the immunocompromised: treatment
Herpes zoster virus (HZV)-treatment
Varicella zoster infection in the immunocompetent: treatment
Varicella zoster infection in the immunocompromised: treatment

Unlicensed Uses

Varicella zoster (chickenpox): neonatal prophylaxis

Administration

For slow intravenous infusion over a period of one hour.

Following reconstitution, the solution may be administered by a controlled-rate infusion pump.

Contraindications

None known

Precautions and Warnings

Children under 18 years
Elderly
Obesity
Restricted sodium intake
Dehydration
Electrolyte imbalance
Neurological disorder
Pregnancy
Renal impairment - creatinine clearance below 51ml/minute
Severe hepatic impairment
Severe hypoxia

Sodium content of formulation may be significant
Advise ability to drive/operate machinery may be affected by side effects
Consult national/regional policy on the use of anti-infectives
Not all presentations are licensed for all indications
Maintain hydration and urinary output
Monitor for signs of neurological toxicity
Reduce dose in patients with creatinine clearance below 51ml/min
Prolonged use may result in superinfection with non-susceptible organisms
In obese patients dosing should be based on ideal weight
Not licensed for all indications in all age groups

Elderly patients have an increased risk of developing neurological adverse effects and should be closely monitored during treatment. These reactions generally resolved after treatment cessation.

High doses should be administered with care, especially in patients with dehydration or renal impairment. Hydration and renal function should be monitored in elderly patients before high doses of aciclovir are administered.

Pregnancy and Lactation

Pregnancy

Use aciclovir with caution during pregnancy.

Schaefer suggests the use of oral aciclovir should be considered for the treatment of first-episode genital herpes in pregnant women. This may prevent neonatal infection by vertical transmission of the virus. Intravenous aciclovir should be used for the treatment of life-threatening maternal infections such as varicella pneumonia or disseminated herpes simplex infection. Schaefer suggests aciclovir should not be administered in cases of uncomplicated herpes zoster (Schaefer 2007). The manufacturers suggest weighing the potential benefits against the risks of using aciclovir during pregnancy.

There is substantial experience regarding the systemic use of aciclovir during human pregnancy. Aciclovir readily crosses the human placenta to the foetus. However, there are no reports of adverse effects to the foetus which are attributable to the use the aciclovir.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Aciclovir is considered safe for use in breastfeeding.

Briggs and Schaefer suggest breastfeeding may continue during therapy with aciclovir. Manufacturer advises caution during use of aciclovir during breastfeeding.

Although aciclovir does transfer into human breast milk, the dosage of aciclovir presented in the milk is expected to be only 1% of a typical infant dosage (at maximum maternal dose). Aciclovir is not expected to cause any adverse effects in breastfed infants.

No special precautions are required, breastfeeding may continue during systemic administration of aciclovir.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abdominal pain
Acute renal failure
Agitation
Anaemia
Anaphylaxis
Angioedema
Ataxia
Blood urea increased
Coma
Confusion
Convulsions
Crystalluria
Diaphoresis
Diarrhoea
Dizziness
Drowsiness
Dysarthria
Dyspnoea
Encephalopathy
Fatigue
Fever
Haematuria
Hallucinations
Headache
Hepatitis
Hives
Hypotension
Increases in hepatic enzymes
Inflammation (injection site)
Jaundice
Lethargy
Leucopenia
Nausea
Necrosis (injection site)
Phlebitis
Phlebitis (injection site)
Photosensitivity
Pruritus
Psychiatric disorders
Psychosis
Rash
Renal impairment
Renal pain
Serum bilirubin increased
Serum creatinine increased
Somnolence
Thirst
Thrombocytopenia
Tremor
Ulceration (injection site)
Urticaria
Vomiting

Presentation

Preparations for solution for infusion containing aciclovir (as aciclovir sodium)

Drugs List

Therapeutic Indications

Uses

Herpes encephalitis
Herpes simplex viral (HSV) infection -immunocompromised
Herpes simplex virus (HSV) infection - prophylaxis (in immunocompromised)
Herpes simplex virus (HSV) infection - severe initial genital herpes
Herpes simplex virus infection in the immunocompetent: treatment
Herpes zoster infection in the immunocompromised: treatment
Herpes zoster virus (HZV)-treatment
Varicella zoster infection in the immunocompetent: treatment
Varicella zoster infection in the immunocompromised: treatment

Unlicensed Uses

Varicella zoster (chickenpox): neonatal prophylaxis

Dosage

The manufacturers suggest a course of treatment usually lasts between 5 and 7 this may be adjusted depending on the condition and response of the patient. For herpes encephalitis, a 10 day course is usually required. Treatment of neonatal herpes infections usually lasts 14 days for mucocutaneous infections and 21 days for disseminated or central nervous system disease.

The duration of prophylactic administration of aciclovir is determined by the duration of the period of risk.

Dosages based on the actual body weight of obese patients may cause higher plasma concentrations of aciclovir. Dosages based on ideal body weight may therefore be required in obese patients.

Adults

Children

Neonates

Patients with Renal Impairment

Administration

For slow intravenous infusion over a period of one hour.

Following reconstitution, the solution may be administered by a controlled-rate infusion pump.

Contraindications

None known

Precautions and Warnings

Children under 18 years
Elderly
Obesity
Restricted sodium intake
Dehydration
Electrolyte imbalance
Neurological disorder
Pregnancy
Renal impairment - creatinine clearance below 51ml/minute
Severe hepatic impairment
Severe hypoxia

Sodium content of formulation may be significant
Advise ability to drive/operate machinery may be affected by side effects
Consult national/regional policy on the use of anti-infectives
Not all presentations are licensed for all indications
Maintain hydration and urinary output
Monitor for signs of neurological toxicity
Reduce dose in patients with creatinine clearance below 51ml/min
Prolonged use may result in superinfection with non-susceptible organisms
In obese patients dosing should be based on ideal weight
Not licensed for all indications in all age groups

Elderly patients have an increased risk of developing neurological adverse effects and should be closely monitored during treatment. These reactions generally resolved after treatment cessation.

High doses should be administered with care, especially in patients with dehydration or renal impairment. Hydration and renal function should be monitored in elderly patients before high doses of aciclovir are administered.

Pregnancy and Lactation

Pregnancy

Use aciclovir with caution during pregnancy.

Schaefer suggests the use of oral aciclovir should be considered for the treatment of first-episode genital herpes in pregnant women. This may prevent neonatal infection by vertical transmission of the virus. Intravenous aciclovir should be used for the treatment of life-threatening maternal infections such as varicella pneumonia or disseminated herpes simplex infection. Schaefer suggests aciclovir should not be administered in cases of uncomplicated herpes zoster (Schaefer 2007). The manufacturers suggest weighing the potential benefits against the risks of using aciclovir during pregnancy.

There is substantial experience regarding the systemic use of aciclovir during human pregnancy. Aciclovir readily crosses the human placenta to the foetus. However, there are no reports of adverse effects to the foetus which are attributable to the use the aciclovir.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Aciclovir is considered safe for use in breastfeeding.

Briggs and Schaefer suggest breastfeeding may continue during therapy with aciclovir. Manufacturer advises caution during use of aciclovir during breastfeeding.

Although aciclovir does transfer into human breast milk, the dosage of aciclovir presented in the milk is expected to be only 1% of a typical infant dosage (at maximum maternal dose). Aciclovir is not expected to cause any adverse effects in breastfed infants.

No special precautions are required, breastfeeding may continue during systemic administration of aciclovir.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abdominal pain
Acute renal failure
Agitation
Anaemia
Anaphylaxis
Angioedema
Ataxia
Blood urea increased
Coma
Confusion
Convulsions
Crystalluria
Diaphoresis
Diarrhoea
Dizziness
Drowsiness
Dysarthria
Dyspnoea
Encephalopathy
Fatigue
Fever
Haematuria
Hallucinations
Headache
Hepatitis
Hives
Hypotension
Increases in hepatic enzymes
Inflammation (injection site)
Jaundice
Lethargy
Leucopenia
Nausea
Necrosis (injection site)
Phlebitis
Phlebitis (injection site)
Photosensitivity
Pruritus
Psychiatric disorders
Psychosis
Rash
Renal impairment
Renal pain
Serum bilirubin increased
Serum creatinine increased
Somnolence
Thirst
Thrombocytopenia
Tremor
Ulceration (injection site)
Urticaria
Vomiting

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Further Information

Last Full Review Date: August 2013

Reference Sources

British National Formulary, 65th Edition (March - September 2013) Pharmaceutical Press, London.

Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

Medications and Mothers' Milk, 14th Edition (2010) Hale, T. Hale Publishing, Amarillo, Texas.

Summary of Product Characteristics: Aciclovir 250mg Powder for Solution for Infusion. Wockhardt UK Ltd. Revised June 2015.
Summary of Product Characteristics: Aciclovir 25mg/ml Sterile Concentrate. Hospira UK Ltd. Revised April 2015.
Summary of Product Characteristics: Zovirax IV 250mg, 500mg. GlaxoSmithKline UK. Revised March 2015.

NICE Evidence Services Available at: www.nice.org.uk Last accessed: 20 June 2017

US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
Available at: https://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT
Aciclovir. Last revised: October 02, 2012
Last accessed: August 16, 2013