According to About.com’s headache and migraine page, women who breastfeed can take some headache meds without exposing their babies to the drugs. The article outlines what precautions mothers should follow if they wish to take abortants or preventives while breastfeeding. Of course, women should consult with their doctors and choose their meds carefully.
Breastfeeding with Head Pain Disorders: What’s Safe, What’s Not and How to Find Out