Dental Drug use in Pregnancy and Breastfeeding
A drug can have more than one harmful effect on the fetus. Individual effects depend on the time of fetal exposure to the drug.
The critical period for teratogenic effects is during organogenesis. This starts at about 17 days after conception and is complete by 60 to 70 days. Exposure to certain drugs during this period (17 to 70 days) can cause major birth defects (Therapeutic guidelines 2019).
A woman may not be aware of her pregnancy until after the early stages of organogenesis. For this reason, drugs in the most severe category of risk (X in the Australian categorisation of drugs in pregnancy) should not be prescribed to a woman of childbearing potential, unless a pregnancy test is negative, and she is using an effective method of contraception (Therapeutic guidelines 2019).
The critical period for teratogenic effects is during organogenesis. This starts at about 17 days after conception and is complete by 60 to 70 days. Exposure to certain drugs during this period (17 to 70 days) can cause major birth defects (Therapeutic guidelines 2019).
A woman may not be aware of her pregnancy until after the early stages of organogenesis. For this reason, drugs in the most severe category of risk (X in the Australian categorisation of drugs in pregnancy) should not be prescribed to a woman of childbearing potential, unless a pregnancy test is negative, and she is using an effective method of contraception (Therapeutic guidelines 2019).
Categorisation of drugs in pregnancy
Drugs has been categorised into several categories by the Australian Therapeutic Goods Administration (TGA) depending on the harmful effects on the
fetus or frequency of malformations. There are 7 categories:
| Category | Description |
|---|---|
| A | Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed. |
| B1 |
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the
frequency of Drug use in pregnancy and breastfeeding 279 malformation or other direct or indirect harmful effects on the human fetus
having been observed.
Studies in animals have not shown evidence of an increased occurrence of fetal damage. |
| B2 |
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the
frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed.
Studies in animals are inadequate or may be lacking, but available data show no evidence of an increased occurrence of fetal damage. |
| B3 |
Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the
frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed.
Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans. |
| C | Drugs which, owing to their pharmacological effects, have caused, or may be suspected of causing harmful effects on the human fetus or neonate without causing malformations. These effects may be reversible. Specialised texts should be consulted for further details. |
| D | Drugs which have caused, are suspected to have caused or may be expected to cause an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Specialised texts should be consulted for further details. |
| X | Drugs which have such a high risk of causing permanent damage to the fetus that they should not be used in pregnancy or when there is a possibility of pregnancy. |
Drug use in breastfeeding
The benefits of breastfeeding are sufficiently important to recommend that it should not be discontinued or discouraged unless there is substantial
evidence that the drug taken by the woman will be harmful to the infant, and no alternative treatment can be found.
Most drugs are excreted only to a minimal extent in breast milk, and in most cases the dosage to which the infant is ultimately exposed is very low and well below the therapeutic concentration for infants. For this reason, few drugs are totally contraindicated while breastfeeding (Therapeutic guidelines 2019).
In most situations, drugs cross the placenta more efficiently than into breast milk. When considering prescribing drugs (particularly longer-term) during breastfeeding, the following checklist may assist in guiding the decision:
Most drugs are excreted only to a minimal extent in breast milk, and in most cases the dosage to which the infant is ultimately exposed is very low and well below the therapeutic concentration for infants. For this reason, few drugs are totally contraindicated while breastfeeding (Therapeutic guidelines 2019).
In most situations, drugs cross the placenta more efficiently than into breast milk. When considering prescribing drugs (particularly longer-term) during breastfeeding, the following checklist may assist in guiding the decision:
- Women's desire to breastfeed
- Availability of non-pharmacological treatment
- Potential for the drug to cause harm, weighed against the benefits of breastfeeding: For the infant, breastfeeding has multiple benefits, including improved immunocompetence (eg decreased rates of otitis media) and enhanced cognitive development (eg increased IQ in the older child). For the woman, breastfeeding provides psychological benefits (eg enhanced maternal—infant attachment) and physiological benefits (eg better uterine involution, decreased risk of breast and ovarian cancers).
Drugs used in the management of oral and dental conditions
| Drug name | TGA pregnancy category [NB1] | Compatibility with breastfeeding [NB2] |
|---|---|---|
| Aciclovir | B3 | Compatible |
| Adrenaline (epinephrine) | A | Compatible |
| Amoxicillin | A | Compatible: may cause diarrhoea in infant |
| Amoxicillin + clavulanate | B1 | Compatible: may cause diarrhoea in infant |
| Amphotericin B | B3 | Compatible |
| Ampicillin | A | Compatible: may cause diarrhoea in infant |
| Articaine | B3 | Use with caution |
| Aspirin | C [NB3] | Compatible with doses up to 150 mg orally, daily; consider alternative if ongoing high-dose therapy is required |
| Benzydamine | B2 | Compatible |
| Benzylpenicillin | A | Compatible; may cause diarrhoea in infant |
| Betamethasone dipropionate | B1 | Compatible |
| Betamethasone valerate | B3 | Compatible |
| Bupivacaine | A | Compatible |
| Cefalexin | A | Compatible; may cause diarrhoea in infant |
| Cefazolin | B1 | Compatible; may cause diarrhoea in infant |
| Celecoxib | B3 [NB3] | Compatible [NB4] |
| Chlorhexidine | A | Compatible |
| Clindamycin | A | Compatible; may cause diarrhoea in infant |
| Clotrimazole | A | Compatible |
| Diazepam | C | Compatible for short-term use; caution with chronic use, monitor infant for drowsiness; short-acting benzodiazepines preferred |
| Dicloxacillin | B2 | Compatible; may cause diarrhoea in infant |
| Doxycycline | D [NB5] | Compatible for short courses (e.g. 10 days) if alternative drug not appropriate; may cause diarrhoea in infant |
| Famciclovir | B1 | Use with caution |
| Flucloxacillin | B1 | Compatible; may cause diarrhoea in infant |
| Fluoride | Unlisted | Compatible |
| Glyceryl trinitrate | B2 | Avoid, insufficient data |
| Hydrocortisone | A | Compatible |
| Hydrogen peroxide | Unlisted | Compatible |
| Ibuprofen | C [NB3] | Compatible [NB4] |
| Lidocaine | A | Compatible |
| Lincomycin | A | Compatible; may cause diarrhoea in infant |
| Lorazepam | C | Compatible; caution with chronic use, monitor infant for drowsiness |
| Mepivacaine | A | Use with caution |
| Methylprednisolone aceponate | C | Compatible |
| Metronidazole | B2 | Compatible; may cause some bitterness in milk and may cause diarrhoea in infant. Consider withholding breastfeeding for 12 to 24 hours after high single dose (2g) treatment |
| Miconazole | A | Compatible |
| Naproxen | C [NB3] | Compatible [NB4] |
| Nitrous oxide | A | Compatible |
| Nystatin | A | Compatible |
| Oxazepam | C | Compatible; monitor infant for drowsiness |
| Oxycodone | C | Use with caution; may cause diarrhoea in infant |
| Paracetamol | A | Compatible |
| Phenoxymethylpenicillin | A | Compatible; may cause diarrhoea in infant |
| Prilocaine (with or without felypressin) | A | Compatible |
| Ropivacaine | B1 | Compatible |
| Salbutamol | A | Compatible |
| Temazepam | C | Compatible; monitor infant for drowsiness |
| Tranexamic acid | B1 | Compatible |
| Triamcinolone acetonide | A | Compatible |
| Trimethoprim + sulfamethoxazole | C | Compatible if infant is healthy and older than 1 month; avoid if infant has glucose6-phosphate dehydrogenase (G6PD) deficiency, is younger than 1 month or has hyperbilirubinemia |
| Vancomycin | B2 | Compatible; may cause diarrhoea in infant |
NB1: Therapeutic Goods Administration (TGA) pregnancy categorisation is from the Prescribing medicines in pregnancy database at the TGA website. See also Australian categorisation of drugs in pregnancy for explanation of the categories.
NB2: Definitions for compatibility with breastfeeding:
| Compatibility | Description |
|---|---|
| Compatible |
There are sufficient data to demonstrate:
|
| Use with caution |
Minor adverse effects in the breastfed infant have been reported, or there are insufficient data to demonstrate:
|
| Avoid, insufficient data |
The characteristics of the drug suggest significant adverse effects are possible and there are insufficient data to demonstrate:
|
| Avoid |
There are sufficient data to demonstrate:
|
NB3: For discussion of nonsteroidal anti-inflammatory drug (NSAID) use for musculoskeletal conditions in women who are pregnant, see 'NSAIDs and reproductive health in women' in eTG complete.
NB4: If an NSAID is required in a breastfeeding patient, diclofenac or ibuprofen is preferred.
NB5: Tetracyclines are safe for use during the first 18 weeks of pregnancy (16 weeks post conception) after which they may affect the formation of the baby's teeth and cause discolouration.
References
Oral and Dental (2019), Therapeutic Guidelines, https://acrobat.adobe.com/id/urn:aaid:sc:AP:df8d5162-f5b2-4605-9d39-1c025810364c