Hi my baby is 1 year 10 month old , he ate fish and without knowing I have given antibiotic and cold syrup, it will cause side effects? What to do

A. If a child has eaten fish why do you have to give a cold syrup for that that I am not understanding having fish is not a problem if you people are non-vegetarian if your child has eaten and there is no problem at all so what’s your concern that I’m not understanding