Antihistamines are medicines that can be used to prevent travel sickness, as in the case of Dimenhydrin (Dramin).
This class of medication should be used 30 or 60 minutes before the trip to have the desired effect at the right time.
Side effects may be drowsiness. and should not be taken with alcoholic beverages, sedatives or tranquilizers, because their effects can be added. Other less common side effects may be blurred vision, confusion, headache, stomach pain, constipation, palpitations or difficulty with urination,
Very young infants and children may be agitated and should not take these medications unless there is medical supervision because too high a dose in a young child can cause hallucinations or even fatal seizures.
People with narrow-angle glaucoma, prostate enlargement, or constipation should take medicine for travel sickness only if the doctor recommends or approves their use.