Breastfeeding and Drugs

This post is about one of an important topic Breastfeeding and Drugs. The choice of safe drugs during pregnancy and breastfeeding is paramount for an obstetrician. The safety profile for mother as well as infant is to be kept in mind. This post covers analgesics, antibiotics, antidepressants and drugs used for complex medical conditions. The points have been extracted from a TOG article which was published in April 2021. I have compiled the information in a tabulated form which will be helpful in quick revision for the exam. 

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Thanks 

 

Introduction

•  Most drugs can be take safely by lactating mothers

•  Medications use during breastfeeding shortens the duration of breastfeeding mainly due to maternal fear of harming the baby

 

Common drugs used in lactation period

Analgesics

•  In postnatal period — analgesia is needed routinely most often after CS, AVB & perineal tear repair

Analgesics	Pharmacokinetics	Drug levels — in mother / infant	Effects on infant	Effect on lactation & breast milk
Paracetamol	•    Non-opioid •    No anti-inflammatory action •    Oral absorption rates depend on gastric emptying	•    Peak in breast milk 1-2 hr after •    Infants exposed to 1%-3.5% of maternal-adjusted dose	No adverse affects
Ibuprofen	•    NSAID 2 arylpropionic acid (2-APA) class •    Oral - rapid & complete absorption  •    Short half-life  •    Low risk of accumulation	•    Undetectable in breast milk	No adverse affects
Codeine	•    Very weak analgesic activity •    Analgesic activity provided by its metabolites Metabolised to •    Morphine, norcodeine & codein-6-glucuronide via CYP2D6 •    Morphine-6-glucuronide via UGT2B7	•    1% of maternal-adjusted dose received by fully breastfed infant •    Plasma clearance prolonged in newborn infants •    Morphine:codeine ratio higher in infant serum	Contraindicated by MHRA to used during lactation	Increased serum prolactin — does not affect ability to breastfeed in established lactation
Aspirin	Rapidly metabolised to salicylic acid	Excreted into breast milk at high levels	•    Metabolic acidosis may occur •    Thrombocytopenia, fever & petechia	No effect
Tramadol	•    Centrally acting •    Structurally related to codeine & morphine •    Agonist at mu opioid receptors •    Inhibits re-uptake of serotonin & noradrenaline	Low excretion into breast milk	Limited	Increased serum prolactin — does not affect ability to breastfeed in established lactation
Morphine	•    Metabolised to inactive morphine-3-gluoronide (60%) & active morphine-6-glucoronide (10%) within 15-20 min of IM or SC & within 30-90 min or oral •    Much lower peak levels after oral use	•    Prolonged plasma clearance in very young infants •    Clearance approach adult level at 2 months of age	Unlikely to be harmful	Delayed lactogenesis

 

Antibiotics

Antibiotics	Pharmacokinetics	Drug levels — in mother / infant	Effects on infant	Effect on lactation & breast milk
Co-amoxiclave	Β-lactam inhibits peptidoglycan synthesis	0.25 - 0.5% of standard infant dose	•    Side effects uncommon •    Restlessness, diarrhoea, rash	Not significant
Flucloxacillin	Β-lactam specially for G+ve organisms	Low	Ocasional diarrea & thrush	Safe to use
Metronidazole	•    Bactericidal  •    Inhibits nucleic acid synthesis in bacterial cells •    Well absorbed orally •    >90% bioavailability  •    Absorption unaffected by infection	•    After topical — plasma levels 1% of that after 250 mg oral dose •    Use only water or gel-based for breast  •    Well distributed in breast milk  •    Infants exposed to less than standard paediatric doses •    Well tolerated	Candida infections & diarrhoea	•    Altered taste of breast milk •    No negative impact on ability to breastfeed
Ciprofloxacin	•    Fluoroquinolone  •    Inhibits DNA gyros & topoisomerase IV	•    Negligible risk after topic use •    After oral infant would receive max of 0.57 mg daily	No effect
Tetracyclines	•    Protein synthesis inhibitor  •    Biostatic  •    Inhibit translation by binding to 30S ribosomal subunit	Avg peak & trough levels approx 6% of maternal weight-adjusted dose	Short-term use unlikely to be harmful
Nitrofurantoin	•    Contraindicated <1 month or in G6PD deficiency	Low	•    Do not use <8 days  after delivery or in G6PD deficiency
Vancomycine & Teicoplanin	•    Mainstay t/m for MRSA •    Poorly absorbed orally	Unlikely to reach infant

 

Anxiety & Depression

 

•  Antidepressants during breastfeeding depend on the drugs used antenatally

•  Abrupt cessation or change of drugs not recommended

•  If antidepressants taken