My daughter is 3 years 10 month old. We have to travel by car for a 12 hr journey, she suffers motion sickness in cars and did have episodes of vomiting in the past. I have used ondem and domstal in the past, but it seems they r not that effective, I have read antihistamine works in these situation, which antihistamine can be used for a 4 years old girl approx, which is gentle and effective enough to make the journey smoother for kid, I am really looking for answers here. Weight is approx 17 kg.