average xanax prescription dosage buy xanax tablets 4 mg green xanax bars can you buy xanax otc in mexico average xanax prescription dosage buy xanax tablets 4 mg green xanax bars can you buy xanax otc in mexico average xanax prescription dosage buy xanax tablets 4 mg green xanax bars can you buy xanax otc in mexico average xanax prescription dosage buy xanax tablets 4 mg green xanax bars can you buy xanax otc in mexico