If it is the exact same medication, I think it is alright. However, if it is a cough and the child has not recovered after finished the prescribed medication, I would go back to the doctor as it seemed like the medication is not working. Would want to try another medication instead if there is no signs of recovery.
If u have given the same medication to ur child before and at the right dosage, I will give. I had done it before and at a safe dosage. At times, I will get more med for standby so I don't have to see pd for common sickness unless it is v serious and child has been unwell for a prolonged period.
Agree with the other mommies, if it's the exact same medicine and your child has no previous issues taking it, then yes I'll let him or her take it. I'd use the spoon prescribed previously with my child's medicine to get the same and exact measurements (if you haven't throw it away that is).
Same medicine but dosage could be diff best to get advice from doc, adult medicine mg is diff, can Google calculate the dosage before given.
if it's the exact same medicine, and your child has taken it before, it's alright. just be sure to adjust the dosage accordingly.