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Treating herpes virus infections during breastfeeding

Published
Topics: AciclovirInfection and infectious diseasesSafety in BreastfeedingValaciclovir

Aciclovir or valaciclovir can be used during breastfeeding. Recommendations apply to full term and healthy infants.

Contents

  1. General considerations
  2. Recommendations
  3. Clinical considerations
  4. Specific recommendations
    1. Aciclovir oral / intravenous
    2. Aciclovir topical / ophthalmic
    3. Valaciclovir
  6. Patient Information
  7. Contact us
  8. About our recommendations
  9. Bibliography

General considerations

It is important to complete an individual risk assessment (SPS page) for your patient and to apply the principles of prescribing in breastfeeding (SPS page) when looking at the available information and making treatment decisions.

This article includes the commonly used antiviral medicines for treating herpes simplex and varicella zoster viral infections such as cold sores, chicken pox, shingles and herpetic genital or eye infections.

Advice is also available on managing viral infections Covid-19 and influenza during breastfeeding.  Some other viral infections, for example HIV, viral hepatitis or cytomegalovirus require highly specialist advice. Contact our specialist service for further advice if the specific infection or antiviral medicine isn’t included here.

Recommendations

Aciclovir is the preferred antiviral for treating herpes simplex and varicella zoster as there are only very small amounts present in breast milk.

Valaciclovir is also an acceptable alternative, since it is converted to aciclovir before passing into breast milk.

Ophthalmic preparations have limited systemic absorption in the mother, and pose negligible risk to a breastfed infant.

Treatment choice should be primarily based on clinical indications, with suitability in breastfeeding as a secondary consideration.

Clinical considerations

The herpes virus cannot be passed on through breastmilk. However, there is a risk of chicken pox to the infant if they come in contact with the shingles sores.  Therefore, if sores are on the breast or close to the nipple, it may not be possible to feed from that breast, although this would need thorough assessment. Infant feeding support should also be sought in order to effectively maintain milk supply.

Specific recommendations

Aciclovir can be used during breastfeeding, but infant monitoring is required.

Infant monitoring

As a precaution, monitor for drowsiness, irritability, skin rashes, vomiting and diarrhoea.

Further information

There is limited published evidence of use in breastfeeding. Only very small amounts pass through into breast milk from oral administration. Intravenous administration will result in higher breast milk levels, however its poor oral bioavailability will limit the amount the infant can absorb from breast milk.

Side effects in the breastfed infant would not be expected. There have been no side effects reported in infants exposed to aciclovir through breast milk.

Aciclovir is used in full-term neonates from birth; the doses used are far greater than the amounts reported in breast milk.

Topical or ophthalmic aciclovir can be used during breastfeeding.

If clinically appropriate, topical routes of administration are usually preferred due to lower systemic concentrations, leading to lower concentrations in breast milk.

Infant monitoring

No specific infant monitoring is usually required. If a side effect is suspected, contact a healthcare professional for further advice.

Further information

Although there is no direct evidence for topical or ophthalmic aciclovir during breastfeeding, systemic absorption is minimal and therefore milk levels will be negligible.

Wash hands thoroughly after application, to ensure the infant does not come into contact with topical or ophthalmic preparations.

Valaciclovir can be used during breastfeeding, but infant monitoring is required.

Infant monitoring

As a precaution, monitor for drowsiness, irritability, skin rashes, vomiting and diarrhoea.

Further information

There is limited published evidence of use in breastfeeding.

Valaciclovir is a prodrug that is rapidly converted to aciclovir in the body and therefore valaciclovir is not expected to be excreted into breast milk.

Only very small amounts of aciclovir have been found in breast milk as a result of valaciclovir administration, and the poor oral bioavailability of aciclovir will limit the amount the infant can absorb from breast milk.

Side effects in the breastfed infant would not be expected.

Patient Information

The NHS website provides advice for patients on the use of specific medicines in breastfeeding.

Contact us

Get in touch with the UK Drugs In Lactation Advisory Service (UKDILAS) (SPS page), our specialist breastfeeding medicines advice service if you need support in the following situations:

  • you need further advice
  • the medicine in question is not included here
  • the infant is unwell or premature
  • multiple medicines are being taken

About our recommendations

Recommendations are based on published evidence where available. However, evidence is generally very poor and limited, and can require professional interpretation. Assessments are often based on reviewing case reports which can be conflicting and lack detail.

If there is no published clinical evidence, assessments are based on: pharmacodynamic and pharmacokinetic principles, extrapolation from similar drugs, risk assessment of normal clinical use, expert advice, and unpublished data. Simulated data is now increasingly being used due to the ethical difficulties around gathering good quality evidence in this area.

Bibliography

Full referencing is available on request