17th May 2025

Breastfeeding

Breastfeeding is recommended by the World Health Organisation (WHO) as the default method of feeding new-borns until they reach 2 years old. Many antibodies and nutrients are transferred to the neonates in the process, but the same occurs for toxins.

List of medications contraindicated in breastfeeding mothers as they can have adverse effects on the baby when passed on through breast milk:

• Amiodarone (theoretical risk of neonatal hypothyroidism from triggering iodine release in infant)
• Antibiotics
  • Clindamycin (risk of infant colitis but incidence is rare)
  • Co-trimoxazole (risk of haemolysis in glucose-6-phosphate dehydrogenase deficient infants)
  • Metronidazole (give breast milk an unpleasant taste that causes babies to refuse it)
  • Nitrofurantoin (risk of haemolysis in glucose-6-phosphate dehydrogenase deficient infants)
  • Quinolone
  • Tetracycline (staining of infant’s teeth and disrupts normal bone growth)
• Aspirin (risk of metabolic acidosis and Reye’s syndrome in infant)
• Cytotoxic drugs
• Iodine
• Methotrexate (should not breastfeed 24 hours after weekly dose)
• Opioids, in particular Codeine and Tramadol (risk of ultra-rapid conversion of codeine and tramadol to their active metabolites can result in unsafe levels, leading to lethargy and respiratory depression in infant)
• Psychiatric medications
  • Clozapine
  • Olanzapine
  • Lithium
• Retinoids
• Hypoglycaemics (found in breast milk in animal studies)
  • Sulfonylurea (theoretical risk of infant hypoglycaemia)
  • DPP-4 inhibitors or gliptins 
  • Pioglitazone
  • GLP-1 analogues