At three years old, the child has sleep problems (wakes up, cries, scr…

At three years old, the child has sleep problems (wakes up, cries, screams). This situation has happened four times in a year. Last time we were prescribed "Edaas-306" for better sleep (it's been six months now). If I give him without a doctor's prescription (the symptoms are the same as in previous cases), will it be harmful?