Dear Editor Cyclic oligosaccharides, cyclodextrins, are increasingly used in clinical practice [1]. A chemically modified γ-cyclodextrin consisting of eight glucopyranose units, sugammadex, is used to reverse neuromuscular blockade induced with rocuronium and other aminosteroid neuromuscular agents. The mode of action of sugammadex is unique: chelation of aminosteroid agents [2]. Human studies in healthy volunteers and patients indicate that sugammadex is well tolerated, but some adverse effects may occur. Themost commonly reported adverse effect of sugammadex is dysgeusia [2]. Other commonly reported adverse events are anesthetic complications, as well as uncommonly reported hypersensitivity reactions, unwanted awareness during anesthesia, and a rare case of anaphylaxis. In October 2010, a 33-years old Caucasian woman with normal body weight (54 kg; height 164 cm) was admitted to our day-case surgical unit for laparoscopic sterilization. In her medical history, she had arterial hypertension. Blood pressures were in good control with the angiotensin-converting enzyme inhibitor (ACEI) enalapril 20 mg once daily. She used an orally administered contraceptive of 3 mg drospirenone and 0.03 mg ethinylestradiol but had no other concomitant medication. She had taken the latest dose of enalapril at 6:00 a.m. and fasted since. For premedication, she received paracetamol 1.5 g by mouth at 8:30 a.m. Normal saline infusion was started, and anesthesia was induced at 10:00 a.m. with midazolam 1 mg, propofol 150mg, and fentanyl 100μg. Rocuronium 30mgwas given to facilitate orotracheal intubation, and she was given dexamethasone 5 mg for postoperative nausea prevention. Anesthesia was maintained with sevoflurane, end-tidal concentration 1.5–2.0%, in oxygen in air, with positive-pressure ventilation. During surgery, she was given fentanyl 100 μg. She had a stable hemodynamic, arterial blood pressure was approximately 130/90 mmHg during intra-abdominal carbon dioxide insufflation and after decompression of the abdominal cavity 105/45 mmHg, and at the end of anaesthesia 124/87 mmHg. At the end of surgery, 30 min after anesthesia induction, she received sugammadex 50 mg (Bridion 100 mg ml, Batch no. 463393, Schering Plough, Oss, Netherlands), and train-offour ratio recovered to 0.9 within 2 min. At 10 min after sugammadex injection, she developed severe hypotension, the lowest arterial blood pressure being 50/30 mmHg. The patient was given etilephrine (total dose 7 mg) and phenylephrine (total dose 0.3 mg) and infused with 1,000 ml normal saline and gelatin 500 ml. Blood pressure returned to normal level within 15min, and she recovered without sequela (Fig. 1). The case was reported to the marketing authorization holder and to the Finnish Medicines Agency. The first case of hypotension after sugammadex was reported in 2006 [3]. In a dose-finding study, a patient who received sugammadex 3mg kg developed deep hypotension consistent with our case within 10min after dosing. Sorgenfrei and colleagues [3] speculated that hypotension was caused by propofol and fentanyl given 2–5 min before the event. In our case, the patient was given propofol and fentanyl earlier during the course of anesthesia, her blood pressure was stable, she was pain free after surgery, and hypotension developed only at 10 min after sugammadex injection. Thus, we believe that sugammadex is the most probable cause of hypotension in this patient. As a concomitant medication the patient used enalapril, and it is known that ACEI may induce hypotension as an interaction with anesthetics [4]. However, with ACEI, it M. Kokki :M. Ali :M. Turunen :H. Kokki Department of Anaesthesiology and Intensive Care, Kuopio University Hospital, School of Medicine, University of Eastern Finland, PO Box 1777, FI-70211 Kuopio, Finland