Cisatracurium besylate, usually referred to as cisatracurium, is a skeletal muscle relaxant used in conjunction with general anesthesia to make intubation easier. It can also be used to facilitate mechanical ventilation in an intensive care setting.1 It is an isomer, or different chemical arrangement, of the molecule atracurium; “cis” refers to the relative positioning of certain chemical groups within the molecule. It was first synthesized in 1989 and earned FDA approval in 1995.2
Cisatracurium is a neuromuscular blocking drug (NMBD) that prevents nerve signals from reaching the muscle and causing muscle contraction by binding to receptors called motor end plates, located at the branching terminals of nerve cells. This prevents the neurotransmitter acetylcholine, which normally is released at the neuromuscular junction, from binding to these receptors, thereby preventing muscle contraction.1
Although side effects from cisatracurium are rare, low blood pressure, rash, slow heart rate, and prolonged neuromuscular blockade have all been reported.3 Patients with myasthenia, a chronic autoimmune disease that causes muscle weakness, can be highly sensitive to the drug, and caution should accordingly be exercised when administering it to them.1
In patients with acute respiratory distress syndrome (ARDS) who have a buildup of fluid in the lungs that can starve organs of oxygen, NMBDs can improve oxygenation and reduce the risk of ventilator-induced lung injury, especially if they are administered early. In one study, patients with ARDS who received cisatracurium within 48 hours of ARDS onset had improved 90-day survival rates and less time on a ventilator compared with patients who received a placebo.4 However, cisatracurium may not be the most effective NMBD in this regard. When compared with the NMBD vecuronium, cisatracurium Separately, atracurium was found to be non-inferior to cisatracurium in terms of improving oxygenation in patients with ARDS, in addition to being cheaper and equally
Other benefits of cisatracurium related to anesthesia have been reported. One study found that cisatracurium lowers the frequency and severity of pain from propofol, a commonly used general anesthetic that can cause pain upon injection.7 The mechanism of this pain alleviation may be similar to that of lidocaine, a local anesthetic known to alleviate propofol injection pain by blocking peripheral nerve pathways. Importantly, a NMBD is required anyway in general anesthesia, so using it to alleviate propofol injection pain obviates the need for other pain relievers, like opioids or steroids, that may introduce new side effects.
Additionally, a fascinating case study reports that a patient who had intractable hiccups—for 19 years!—did not respond to treatment until physicians administered cisatracurium after the hiccups led to insomnia, vomiting, and shortness of breath. The patient had no hiccups after the medication wore off, and when hiccups recurred two weeks later, a new round of cisatracurium once again rid him of hiccups.8
References
1. Strawbridge, A. D., Khanna, N. R., Patel, P. & Hauser, J. M. Cisatracurium. in StatPearls (StatPearls Publishing, Treasure Island (FL), 2025).
2. PubChem. Cisatracurium Besylate. https://pubchem.ncbi.nlm.nih.gov/compound/62886.
3. Konstadt, S. N. et al. A two-center comparison of the cardiovascular effects of cisatracurium (Nimbex) and vecuronium in patients with coronary artery disease. Anesth. Analg. 81, 1010–1014 (1995), DOI: 10.1097/00000539-199511000-00020
4. Papazian, L. et al. Neuromuscular blockers in early acute respiratory distress syndrome. N. Engl. J. Med. 363, 1107–1116 (2010), DOI: 10.1056/NEJMoa1005372
5. Sottile, P. D. et al. An Observational Study of the Efficacy of Cisatracurium Compared with Vecuronium in Patients with or at Risk for Acute Respiratory Distress Syndrome. Am. J. Respir. Crit. Care Med. 197, 897–904 (2018), DOI: 10.1164/rccm.201706-1132OC
6. Carabetta, S. M., Allen, B., Cannon, C., Hailu, K. & Johnson, T. Atracurium Versus Cisatracurium in the Treatment of Acute Respiratory Distress Syndrome. J. Pharm. Technol. JPT Off. Publ. Assoc. Pharm. Tech. 39, 212–217 (2023), DOI: 10.1177/8755122523119403
7. Kim, Y.-H., Namgung, J. & Lim, C.-H. Cisatracurium pretreatment with tourniquet reduces propofol injection pain: a double-blind randomized controlled trial. J. Int. Med. Res. 42, 360–367 (2014), DOI: 10.1177/0300060514522602
8. Jp, W., Jx, A., Xy, Q. & Y, W. Successful Treatment of Idiopathic Intractable Hiccup With Cisatracurium Under Intravenous General Anesthesia: A Case Report. AA Pract. 10, (2018), DOI: 10.1213/XAA.0000000000000651