There is no established therapeutic level for meclizine. Just like any drug, patients require clinical monitoring for any adverse reactions. To prevent motion sickness, take Antivert https://sober-house.org/medications-for-alcohol-use-disorder/ about 1 hour before you travel or anticipate having motion sickness. You may take Antivert once every 24 hours while you are traveling, to further prevent motion sickness.Meclizine: Uses, Dosage & Side Effects