OK, here's what I have on cold medicine from
The Nursing Mother's Companion by Kathleen Huggins, who is a nurse and lactation consultant. I got her book because the lactation consultant who did my breastfeeding class recommended it for the drug reference. Anyway...
Oral decongestants can cause agitation or fussiness in your infant, and , most importantly, they may decrease your milk supply. I you are planning on using an oral product, choose one with 30 milligrams or less of pseudophedrine or phenylpropanolomine per dose; avoid sustianed-release products. Nasal sprays (Afrin, Nostrilla) are preferable to oral drugs.
As for antihistamines...
High doses of antihistamines, particularly when in combination with a decongestant ,may perhaps decrease milk flow. Use no more than necessary to control symptoms; often a single dose at bedtime is sufficient. If you are planning to use an oral product, choose one with 2 milligrams or less of chlorpheniramine or brompheniramine per dose, or 25 milligrams or less of diphenhydramine per dose, and avoid sustaine-release products. Loratadine and fexofenadine are well tolerate by infants and are preferred over the older sedating antihistamines. Cetirizine is a new antihistamine that can cause drowsiness and may possibly affect lactation. It is not a good choice while nursing.
So, like I said, this came from a book, and not any doctor, so you can take it as you wish. I hope this helps you with what you were looking for, or gives you some good alternatives. And, most of all, I hope you feel better soon!