Drugs List

Therapeutic Indications

Uses

Herpes simplex
Herpes simplex virus (HSV) infection - genital
Herpes simplex virus (HSV) infection - herpes labialis

Contraindications

None known

Precautions and Warnings

Immunosuppression
Breastfeeding
Pregnancy

Not all available brands are licensed for all indications
Some products may have a pharmacy only legal classification
Avoid contact with eyes
Avoid contact with mucous membranes
Not for intravaginal use
Not for oral use

Pregnancy and Lactation

Pregnancy

Use aciclovir with caution in pregnancy.

Aciclovir does cross the placenta (Schaefer, 2007 and Briggs, 2011) however, following topical use of aciclovir there is minimal absorption through the skin (Schaefer, 2007) and systemic exposure will be low. There is also significant experience of systemic aciclovir use in pregnancy and no evidence of an increased risk of congenital defects, adverse foetal or neonatal outcomes were found during a manufacturer - CDC organised pregnancy registry between 1984 and 1999 (Briggs, 2011). Three standard animal studies revealed no teratogenic effects although abnormal thymus and immune system resulted in rats when doses causing maternal toxicity were used (Briggs, 2011).

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

Use aciclovir with caution in breastfeeding.

The manufacturer indicates that the nursing infant will receive an insignificant amount of aciclovir following maternal topical use. Whilst aciclovir is found in breast milk, the highest maternal systemic dosages only result in the infant receiving a dose 1% of that which might be prescribed. This would not be expected to result in any adverse effect in breastfed infants.

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

Angioedema
Contact dermatitis
Dry skin
Erythema
Hypersensitivity reactions
Itching sensation (local)
Scaling of skin
Stinging (transient)
Transient burning
Urticaria

Presentation

Cream containing aciclovir

Drugs List

Therapeutic Indications

Uses

Herpes simplex
Herpes simplex virus (HSV) infection - genital
Herpes simplex virus (HSV) infection - herpes labialis

Dosage

Adults

Elderly

Children

Additional Dosage Information

Contraindications

None known

Precautions and Warnings

Immunosuppression
Breastfeeding
Pregnancy

Not all available brands are licensed for all indications
Some products may have a pharmacy only legal classification
Avoid contact with eyes
Avoid contact with mucous membranes
Not for intravaginal use
Not for oral use

Pregnancy and Lactation

Pregnancy

Use aciclovir with caution in pregnancy.

Aciclovir does cross the placenta (Schaefer, 2007 and Briggs, 2011) however, following topical use of aciclovir there is minimal absorption through the skin (Schaefer, 2007) and systemic exposure will be low. There is also significant experience of systemic aciclovir use in pregnancy and no evidence of an increased risk of congenital defects, adverse foetal or neonatal outcomes were found during a manufacturer - CDC organised pregnancy registry between 1984 and 1999 (Briggs, 2011). Three standard animal studies revealed no teratogenic effects although abnormal thymus and immune system resulted in rats when doses causing maternal toxicity were used (Briggs, 2011).

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

Use aciclovir with caution in breastfeeding.

The manufacturer indicates that the nursing infant will receive an insignificant amount of aciclovir following maternal topical use. Whilst aciclovir is found in breast milk, the highest maternal systemic dosages only result in the infant receiving a dose 1% of that which might be prescribed. This would not be expected to result in any adverse effect in breastfed infants.

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

Counselling

Advise patients to apply the cream to the lesion as near as possible to the start of infection. Treat recurrent episodes during the prodromal period or when lesions first appear.

Advise cold sore sufferers to avoid transmitting the virus, particularly when active lesions are present.

Advise patients to wash their hand before and after applying the cream, and to avoid unnecessary rubbing of the lesions or touching them with a towel, to avoid aggravating or transferring the infection.

Side Effects

Angioedema
Contact dermatitis
Dry skin
Erythema
Hypersensitivity reactions
Itching sensation (local)
Scaling of skin
Stinging (transient)
Transient burning
Urticaria

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: April 2016

Reference Sources

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.

Joint Formulary Committee. British National Formulary. 71st ed. London: BMJ Group and Pharmaceutical Press; 2016.

Paediatric Formulary Committee. BNF for Children 2015-2016. London: BMJ Group, Pharmaceutical Press, and RCPCH Publications; 2015.

Medications and Mothers' Milk, Sixteenth Edition (2014) Hale, T and Rowe, H, Hale Publishing, Plano, Texas.

Summary of Product Characteristics: Aciclovir 5% w/w cream. Pinewood Healthcare. Revised July 2014.
Summary of Product Characteristics: Lipsore 5% w/w cream. Relonchem Limited. Revised August 2015.
Summary of Product Characteristics: Zovirax cream. GlaxoSmithKline UK. Revised December 2013.
Summary of Product Characteristics: Zovirax Cold Sore cream. GlaxoSmithKline Consumer Healthcare. Revised March 2014.

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
Acyclovir. Last revised: 10 March 2015
Last accessed: 13 April 2016