Can a 3 and a half old baby take histex pd drops for cough and congestion?

The PD drops should tell you the ages that they are. to be used for , the amount advised and how often . Good Luck

I would not use this or any other antihistamine in a kid that age. They thicken secretions and do nothing of value other than letting you think you are helping. If the nose is congested, clean it out with saline nose drops and suction. Any cough at that age is a protective mechanism to clear the airways.

Nasal saline is often helpful in reducing congestion and post nasal drip.