alprazolam, trade name xanax is a fast action benzodiazepine with focus on reducing anxiety, after 24 hours most of it will already be gone, and is ok redosing.
tolerance is crossed so you will build tolerance for other benzodiazepines as well, 2 weeks of daily taking can cause phisical addiction and make you need bigger doses.
i starded with 0,25 3 times daily, now 1,5 years later i am on 10mg daily, 3 in the morning 3 in the afternoon and 4 to sleep
if you use them once a week i think tolerance will grow slowly.
but , really , be careful with benzos, its dangerous road.