Drugs and breastfeeding

• No drug is absolutely contraindicated - need to balance potential risks and benefits and the availability of alternative therapies.
• The only drugs known to carry a serious risk of harming the breast-fed baby are anti-thyroid agents. 
The concentration of propylthiouracil may be higher in milk than in maternal plasma.
• Aspirin - Possible risk of Reye's syndrome
• Carbimazole - May affect neonatal thyroid function, nodular goitre - avoid
• Lithium - Risk of toxicity - hypotonia
• Nalidixic acid- can cause haemolytic anaemia
• Propylthiouracil - Risk of hypothyroidism / agranulocytosis / nodular goitre - avoid
• Senna - causes purgation
• Tetracyclines - Possibility of dental discolouration