Generally pregnant women or breast feeding women should not be prescribed any medication unless confirmed and prescribed by Doctor.
But in some situations like acute or chronic infections or systemic disorders which affects pathologically may need some prescriptive drugs,but those drugs are chosen on the basis of Safety usage of drugs in pregnant women and risk of infantile affects of drugs in breast feeding mothers,postulated by FDA.
In your case antibioitcs for acute or mild chronic infections can be prescribed safely for first line medications like Amoxicillin,Azithromycin where as Tetracyclines are absolutely contraindicated.
Other adjunctive medications like nasal decongestants, bronchodilators, anti histaminics etc may have an alternative drugs which are proved to be safe with no minimal side effects in growing infants.This depends on the drug properties if they will be transferred as therapeutic formulations un altered in to the breast milk.
Here are some references which are clinically observed for safe use of certain classes of drugs in breast feeding mothers.Please refer to it and talk to your Doctor about your situation,clear all your doubts before you get a complete prescription.Please keep us updated.
http://www.infantrisk.com/content/antibiotics-and-breastfeeding
http://www.medsafe.govt.nz/profs/puarticles/lactation.htm
You should not be breast feeding while taking antibiotics. Period. The various classes of antibiotics work by interfering with cell replication and that is the last kind of medication you want to have your child ingest. The good news is that they will completely clear from your system several weeks after taking them.
Antibiotics taken during pregancy are always dangerous. The problem is that you may die from an untreated infection and that would mean loss of both you and the child.