Nardi A E, Valença A M, Nascimento I, Mezzasalma M A, Zin W A
Laboratory of Panic and Respiration, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Psychiatry Res. 2000 May 15;94(2):179-84. doi: 10.1016/s0165-1781(00)00135-9.
The inhalation of 35% carbon dioxide has consistently been shown to provoke panic attacks in panic disorder patients. We aim to determine if an acute dose of clonazepam (2 mg) attenuates the panic attacks induced by an inhalation of 35% carbon dioxide in panic disorder. Twenty-two panic disorder patients who had been drug-free for 1 week participated in a carbon dioxide challenge test 1 h after a dose of either 2 mg of clonazepam or placebo with a randomized double-blind method. Also in a double-blind design during the tests the patients inhaled either atmospheric compressed air ('placebo control') or the carbon dioxide mixture. All patients participated in both tests which were done with a 20-min interval. Immediately before and after the inhalation, the anxiety levels and the symptoms of panic were always assessed. In the clonazepam group (n=11) two patients (18.2%) had a mild panic attack and in the placebo group (n=11) nine patients (81.8%) had a moderate to severe panic attack in the CO(2) challenge test. No patient had panic attacks during inhalation of atmospheric compressed air although anticipatory anxiety levels tended to be higher than in the CO(2) tests. After the CO(2) test anxiety levels were significantly greater in the CO(2) group (three-way ANOVA with Geisser-Greenhouse adjustments, F(31.92,1.86)=17.15, d.f.=7, P=0.013). Although a small sample was studied, the findings suggest the efficacy of an acute dose of clonazepam in attenuating panic attacks induced by carbon dioxide inhalation.
一直以来，研究表明吸入35%的二氧化碳会诱发惊恐障碍患者的惊恐发作。我们旨在确定一剂氯硝西泮（2毫克）是否能减轻惊恐障碍患者吸入35%二氧化碳所诱发的惊恐发作。22名已停药1周的惊恐障碍患者采用随机双盲法，在服用2毫克氯硝西泮或安慰剂1小时后参加二氧化碳激发试验。在试验过程中同样采用双盲设计，患者吸入大气压缩空气（“安慰剂对照”）或二氧化碳混合物。所有患者都参加了这两项间隔20分钟进行的试验。在每次吸入之前和之后，都会评估焦虑水平和惊恐症状。在氯硝西泮组（n = 11）中，两名患者（18.2%）出现轻度惊恐发作，而在安慰剂组（n = 11）中，有九名患者（81.8%）在二氧化碳激发试验中出现中度至重度惊恐发作。在吸入大气压缩空气期间，没有患者出现惊恐发作，尽管预期焦虑水平往往高于二氧化碳试验。在二氧化碳试验后，二氧化碳组的焦虑水平显著更高（采用Geisser - Greenhouse校正的三因素方差分析，F(31.92,1.86)=17.15，自由度 = 7，P = 0.013）。尽管研究样本较小，但研究结果表明一剂氯硝西泮在减轻二氧化碳吸入诱发的惊恐发作方面具有疗效。
