I have a runny nose. can u tell me what medicine can i use for it. also, my baby he is 21 months has the cold like me. what can i do for him?

Several options: The easiest way to treat the symptom of runny nose is over the counter antihistamines (like Allegra (fexofenadine) or zyrtec). For your 21-month old, i would not use these medications (not approved for those less than age 2)--i would recommend having your baby see his pediatrician.

Colds go away: Colds are self limited, they go away by themselves. Drugs can cause permanent harm, even otc ones. Long term problem for short term gain makes no sense. Antihistamines are ineffective for viral colds (& dangerous to babies). Decongestants work by constricting blood vessels, not only in the nose, but all over the body, including brain. Stay hydrated, rest. This advice even more so for baby.