I need something for preventive altitude sickness. i have acetak. what dosage should i take? 250 mg twice a day starting a day before my hike?

Not familiar: With 'acetak'. Typically hace is treated with Diamox (acetazolamide) 250mg twice to four times daily beginning 24-48hours before ascent. Needs to be prescribed by a physician. Have fun and be cautious.

That should do it: The best is to acclimatize slowly.

Wait!: That dose is for treatment of altitude sickness not prevention unless you weigh >220 pounds, wildern 125 mg twice a day starting 24 hours before planned altitude is usual dose. But what altitude are you going to ; what rate ascent? Do you know warning signs, side effects medicines, other ways to avoid altitude sickness? See a travel or wilderness specialist if you can first.