4-12yr medicine

My son turns 4 in Jan(3months from now).... my husband got this medicine. Can he take it? We live an HOUR away from Walmart that he stopped at to get this. He was so excited to find it, he didn't even look at the age range..... fml We can't get back to the store until probably Wednesday or Thursday..... 💔 Please tell me there's a way.... his coughing is SO bad at night. 💔 Edit: added pic. I forgot to add it. He also Weighs 48lbs. According to Google he signs 4lbs more than a "typical" 4yr old.