Bonine is contains meclizine and is used mainly for motion sickness. The cause of nausea in high altitude sickness and motion sickness is different. Therefore, meclizine does not work in nausea due to high altitude sickness. Of course, it works in motion sickness. Diamox (acetazolamide) is very effective in high altitude sickness and it is the recommended treatment. Advice 1. Tablet Diamox every 8 hours orally. Start taking 24hours before ascent and continue for at least 48 hours while at high altitude 2. You can also take ibuprofen 600 mg orally before ascent if you also feel headache 4. For full fledged vomiting you can take domperidone 10 mg per oral 5. Avoid alcohol, smoking, spicy food and strenuous activity 6. Drink at 4 – 5 liters of uncontaminated water daily 7. Ascent slowly 8. Keep glucose and mix it with water and drink slowly for energy Thanks