Alprazolam treatment was tapered in 17 panic patients at a rate of 10% of the starting dose every 3 days. Only four subjects completed withdrawal on schedule (4-5 weeks); four additional subjects discontinued treatment in 7-13 weeks. During withdrawal 15 patients had recurrent or increased panic attacks and nine had significant new withdrawal symptoms. Most common among the latter were malaise, weakness, insomnia, tachycardia, lightheadedness, and dizziness. None had seizures, psychosis, or significant neurological or EEG abnormalities. Results indicate that relapse and withdrawal are important considerations in the choice of alprazolam treatment for panic attacks.