laumiere, very, very few meds cannot be taken when bf. Even the heaviest-duty antibiotics can be taken - it's a judgement call. You can do the research yourself, share your findings with the doc, and decide with his/her advice what to do.
What you might avoid with a newborn or a pre-term may not present an issue with a 5 month old.
Thanks tiktok, I suspected as much but it's really hard to get any info out of our HCPs, they won't even prescribe the Pill if you're BF (mini-Pill is acceptable thankfully). Are there any sites you'd recommend for researching this?
If you look on the Breastfeeding Network website there is information about drugs in breast milk. There is also a helpline you can ring, where you can speak to someone (a pharmacist I think) about the drugs you need to take. They have a database about the safety of various drugs. I found them very helpful when I contacted them.