Meclizine is a powerful antihistamine designed to counteract the effects of histamine, a natural chemical in your body that can cause discomfort. It's highly effective for preventing and treating nausea, vomiting, and dizziness related to motion sickness. For optimal results, take Rugby's Meclizine caplets an hour before you start your journey. However, if you have liver or kidney issues, asthma, glaucoma, an enlarged prostate, or difficulties with urination, be sure to consult your doctor before use.