I was told that over the counter drugs are not recommended to treat baby cold.why is this?

They don't work: Over-the-counter cold medicines are not for babies. They don't work in babies (or young kids). Also, the ingredients in them are often not safe for babies and can cause serious side effects. Please talk to your pediatrician prior to giving any medicine to your baby (even if over the counter). Just because it's sold in stores or in baby aisle, doesn't mean it's safe.

Risk/benefit issue: OTC cold preparations basically give parents something to do during a cold until it passes.They have little if any proven benefit in younger kids. Occasionally, one parent gives the med not realizing the other has already done so and overdoses account for a significant number of emergency room visits/yr.