Effects of Alprazolam on Gas Exchange,Breathing Pattern,and Lung Function in COPD Patients with Anxiety

Abstract

We studied the effects of alprazolam compared to placebo in patients with chronic obstructive pulmonary disease (COPD) exacerbated by anxiety. In a randomized double-blind crossover protocol, patients received either placebo or alprazolam 0.25 mg three times daily for 2 weeks. All 12 patients enrolled in the study had an initial arterial ${\text{P}}_{{\text{CO}}_{\text{2}}}⩽40$ . Resting baseline values for spirometry, arterial blood gases, ${\dot{V}}_{{\text{O}}_2}$ , ${\dot{V}}_{{\text{CO}}_2}$ , ${\dot{V}}_{\text{E}}$ , and T_i/T_tot were compared to the values obtained on placebo and alprazolam. Eight patients completed the study. Three of the 4 patients who dropped out complained of increasing dyspnea on placebo. This adverse reaction was mentioned as a possible side effect when the informed consent was obtained, indicating that the power of suggestion may have had a strong influence in this group of patients. Our data suggest that small doses of alprazolam cause no adverse effects nor CO₂ retention. Alprazolam did not alter the ${\dot{V}}_{\text{E}}$ , ${\dot{V}}_{{\text{O}}_2}$ , T_i/T_tot, or sensation of breathlessness. Thus, stable normocapnic patients with moderate COPD can be given small doses of alprazolam safely to relieve anxiety or depression.