Yes and no. There are many meds you can take while breastfeeding that you couldn't take while pregnant (like NSAIDs), however there are also meds that were fine to take during pregnancy that you shouldn't take while breastfeeding (like cough/cold medicines). Always best to talk with your Dr before taking any meds
Ask your dr if the meds are safe while breastfeeding, if not, request that he gives you some that are safe.