The International Classification of Sleep Disorders of the American Academy of Sleep Medicine describes insomnia secondary to drugs or substances, highlighting some of the features which characterize it: (a) the iatrogenic nature (b) the diverse range of effects on sleep structure by the different substances, (c) the failure or the partiality of knowledge about it. FG, male, 82 years old, suffering from prostate cancer-treatment with bicalutamide (50 mg/day orally) and leuprorelin (3.75 mg sc per month), is hospitalized in urology for the evidence of two bladder neoplasms. Pre-treated with blood transfusions of G.R. concentrated, is undergoing surgery, in the postoperative setting is further transfused IIa and presents in the day, in the absence of subjectivity and objectivity in character infectious diseases, insomnia and severe decompensated respiratory acidosis associated with acute respiratory failure type II, which progresses despite medical therapy and oxygen-therapy. Speaking to counseling should be the day for the worsening of the clinical picture, is in the differential diagnosis TRALI with bilateral pleural effusions and it starts with the noninvasive mechanical ventilation with interface oro-nasal and oxygen. The urgency in making a HRCT allows you to exclude the commitment interstitial and to confirm the bilateral pleural effusions. Then, are performed in succession, two thoracentesis, right and left, in the course of non-invasive mechanical ventilation, with the respectively extraction of 1000 and 1700 ml of pleural fluid, which turns out to be a transudate. Meanwhile, ventilatory treatment allows a progressive compensation of respiratory failure, the follow-up ultrasound shows the gradual reformation of the pleural effusion bilaterally. The diagnostic analysis is then focused on insomnia marked: you run a PSG in the course of therapy and proves increase of latency, sleep fragmentation and made surface with marked reduction of N2 and especially REM sleep. While the bilateral recurrent hydrothorax is treated with the placement of pleural drainage, a series of investigations in blood chemistry are performed, designed to confirm the suspicion of a clinical condition consistent with the immediacy of insomnia and hydrothorax by drugs and / or substances (surgical stress-Cortisol-CRH-bicalutamide-leuprorelin-FSH-LH-DHEA). Discontinuation of treatment with bicalutamide and dose adjustment of leuprorelin have permission to remove the pleural drainage through exhaustion of recurrence hydro-thorax bilateral. The patient was discharged in XLIIIa day. The knowledge and the cultural-methodological approach of the Sleep Medicine are almost always a real added value for a proper understanding of reality from respiratory clinics proposals in the various forms in which it manifests itself. The clinical case presented is paradigmatic of how Pulmonology intensivist is intimately hawksbill terms of pathophysiology and clinical interpretation, with the Sleep Medicine and how it is useful to have both the same cultural and methodological approaches. 1. Spitz A, Young JM, Larsen L, Mattia-Goldberg C, Donnelly J, Chwalisz K. “Efficacy and safety of leuprolide acetate 6-month depot for suppression of testosterone in patients with prostate cancer”. Prostate Cancer Prostatic Dis. 2011 Oct 25. doi: 10.1038/pcan.2011.50. 2. Tanaka N, Fujimoto K, Hirao Y, Shimizu K, Tsujimoto S, Samma S. “Endocrine response to a single injection of goserelin 3.6 mg or leuprolide 3.75 mg in men with prostate cancer. Arch Androl. 2007 Mar-Apr;53(2):87-90. 3. Ferrari B, Pezzuto A, Coppola F. “Massive ascites and hydrothorax after leuprolide acetate administration in a down-regulated woman undergoing assisted reproduction”. Fertil Steril. 2007 Oct;88(4):968.e9-11. Epub 2007 Apr 16. 4. Lodde M, Lacombe L, Fradet Y. “Salvage therapy with bicalutamide 150 mg in non metastatic castration-resistant prostate cancer”. Urology. 2010 Nov;76(5):1189-93. Epub 2010 Mar 29. 5. Akaza H. “Combined androgen blockade for prostate cancer: review of efficacy, safety and cost-effectiveness”. Cancer Sci. 2011 Jan;102(1):51-6. doi: 10.1111/j.1349-7006.2010.01774.x. Epub 2010 Nov 22. Review. 6. Labrie F. “Hormonal therapy of prostate cancer”. Prog Brain Res. 2010;182:321-41.