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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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
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Analgesics
- In postnatal period — analgesia is needed routinely most often after CS, AVB & perineal tear repair
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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 | Î’-lactam inhibits peptidoglycan synthesis | 0.25 - 0.5% of standard infant dose | • Side effects uncommon • Restlessness, diarrhoea, rash | Not significant |
Flucloxacillin | Î’-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
- All through pregnancy — 37% less likely to breastfeed
- From 3rd trimester — 75% less likely to breastfeed
- Must support & reassure the patient
Drugs | Drug levels — in mother / infant | Effect on lactation & breast milk |
SSRI | Sertaline — SSRI of choice • Low levels in breast mil • Not detected in infant serum | If SSRI used during pregnancy & lactation, mother may struggle with breastfeeding |
Fluoxetine — higher average level in breast milk • Can cause colic & drowsiness • No long term adverse developmental outcomes • Do not stop if needed by mother • Monitor infants | ||
TCA | • Low levels in breast milk • May cause drowsiness & sedation | |
Others | Venlafaxine — relatively higher dose transferred to infants |
High Blood Pressure
VTE and Breastfeeding
Drugs | Drug levels — in mother / infant |
Warfarin | • Very low levels in breast milk • No effect on vitamin K-dependent clotting factors • No special precautions required |
LMWH | • Not excreted into breast milk or absorbed by an infant |
Direct oral anticoagulants | • Not recommended as first-line t/m in pregnancy / lactation • Paucity of safety data |
Complex Medical Problems
Condition/ Drugs | Mother / Infant |
Asthma | Beta-2 Agonists & Steroid Inhalers —Safe Montelukast — low levels excreted & can be used in children as young as 6 months High-dose Steroids — can continue breastfeeding with short courses |
Steroids | Prednisolone — safe up to 40 mg/day • Poorly excreted into breast milk |
Monoclonal antibodies | • Paucity of safety data • Excretion into breast milk minimal • Absorption minimal Adalimumab / Inflximab — no adverse effects, be cautious |
Antiepileptic drugs | • Some drugs (e.g. phenytoin, carbamazepine) enhance metabolism of other drugs, whereas other (e.g. valproic acid) slow metabolism Levetiracetam — low levels excreted in breast milk, safe to use, may reduce breast milk supply in some Lamotrigine — encourage to breast feed. Need to monitor serum levels in infant & adjust the dose Sodium valproate — reassuring safety profile, can be used |
Contraception and Breastfeeding
Emergency Contraception
- No special precautions
- If used Ulipristal Acetate (ellaOne) — avoid breastfeeding for 1 week
Key messages
- Lactational amenorrhea can be up to 98% effective if following criteria met
- Fully breastfeeding, infant age less than 6 months, woman amenorrhic
- If not breastfeeding — contraception required from 21 day postpartum
- Safe to use in breastfeeding women — POP, Injectables
- From 6 wks breastfeeding women can use — COCP, Patch
- Cu-IUCD & LNG-IUS can be fitted within 48 hrs of delivery
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