Neuromuscular blockers (NMBs) are commonly used in anesthesia to facilitate tracheal intubation and optimize surgical conditions. However, these compounds share a common side effect -the risk of an allergic reaction. Anaphylactic shock is a rare (approximately one case in 10,000-20,000 procedures) but life-threatening complication of anesthesia. 1 In France, various epidemiological studies over the last three decades have shown that the most common causal agents of anaphylaxis are NMBs. 2 In the event of anaphylactic shock, epinephrine is the first-line therapy. The dose is usually titrated -except in case of cardiac arrest -depending on the clinical presentation and based on heart rate and blood pressure, to avoid the occurrence of arrhythmia with large doses of epinephrine. 3 This symptomatic treatment, coupled with crystalloid fluid resuscitation, allows to counteract hemodynamic (decreased blood pressure and cardiac output) and respiratory (bronchoconstriction) effects of the numerous mediators that are released during the course of an anaphylactic reaction. Despite these measures, the outcome remains potentially lethal in approximately 10% of cases. 4 However, there is no specific therapy of NMBassociated anaphylaxis. Proposed therapies could involve a substance able to rapidly inhibit the anaphylactic reaction by masking or binding the causal allergen. A specific therapy for the anaphylactic reaction to dextran, used in some countries as a fluid therapy, was attempted during the 1980s with the arrival on the market of a dextran-inhibitor hapten. 5 This hapten was purported to reduce the allergystimulating effects of dextrans through specific inhibition. The effectiveness of this preventive strategy proved unreliable, notwithstanding the other adverse effects of dextrans, renal in particular. 6 Thus, there remains no specific strategy at this time regarding the prevention or treatment of allergic reactions to NMBs. Could this situation change with the recent availability of sugammadex? Sugammadex is a gammacyclodextrine that was modified by the addition of side chains that specifically encapsulate the steroidal core of the NMB, mainly through interactions between the negative charges of the cyclodextrine molecule and the positive charges of the quaternary ammonium ions. 7 Their binding at the centre of the cyclodextrine molecule, more specifically the sterol moiety, is strong and prolonged, implying the presence of various high-energy chemical bonds. Binding is rapid, and steroidal NMBs show a high affinity for sugammadex, especially rocuronium and to a lesser degree vecuronium. 8 Beyond the rapid reversal of NMBs allowed by sugammadex, 7 neutralizing the NMB molecules by masking the causal allergen (i.e., the quaternary ammonium ion) should also be considered when an NMB-related allergic event is suspected. This hypothesis was reported for the first time through a case report. 9 The authors of that report described a serious anaphylactic reaction that occurred immediately after an induction sequence that i...