Cisatracurium besylate is an intermediate-acting, non-depolarizing neuromuscular blocking drug (NMBD). Cisatracurium has a benzylisoquinolinium structure and is the 1R cis-1’R cis isomer of atracurium. Metocurine and d-Tubocurarine are also in the benzylisoquinolinium class.[1] As an NMBD, it has found use as an adjunct to general anesthesia facilitating tracheal intubation and providing skeletal muscle relaxation during surgery.  It may also be used to provide skeletal muscle relaxation to facilitate mechanical ventilation in an intensive care unit setting, but must be used with sedation.[2][3]

Pancuronium bromide is a long-acting, bis-quaternary aminosteroid, non-depolarizing, neuromuscular blocking drug (NMBD) which was first synthesized in 1964 and was found to possess fewer adverse effects with regards to hemodynamic stability and histamine release as compared to the prototypical NMBD, d-tubocurarine.[1][2] After the arrival of intermediate-acting NMBDs such as vecuronium, rocuronium, cisatracurium, and atracurium, the use of pancuronium has fallen out of favor with many clinicians due to its long elimination and context sensitive half time and predominantly renal clearance.

Neuromuscular blockade is frequently used in anesthesia to facilitate endotracheal intubation, optimize surgical conditions, and assist with mechanical ventilation in patients who have reduced lung compliance. Neuromuscular blocking agents (NMBAs) come in two forms: depolarizing neuromuscular blocking agents (succinylcholine) and nondepolarizing neuromuscular blocking agents (rocuronium, vecuronium, atracurium, cisatracurium, mivacurium). The class of NMBA used for achieving neuromuscular blockade must be selected carefully based on patient factors, the type of procedure being performed, and clinical indication.

The objective of this retrospective study was to report the clinical use of atracurium and its reversal with neostigmine in pet rabbits. The medical records of 14 rabbits undergoing anaesthesia for ophthalmic surgery were located through a search of the hospital's database. Demographic data and data pertaining to the use of the neuromuscular blocker and its reversal were analysed. After intravenous administration of 0.44±0.4 mg/kg atracurium (total dose), 11 rabbits experienced at least one of the following cardiovascular responses: hypotension, defined as systolic arterial pressure less than 75 mmHg (n=6), hypotension with decreased heart rate (HR) (n=1), hypotension with increased HR (n=1), decreased arterial blood pressure (ABP) without hypotension (n=6), decreased ABP with decreased HR (n=1), or increased HR (n=2, ABP reading could not be taken). Two of these 11 rabbits also experienced severe intraoperative hypothermia. The neuromuscular block was monitored with a train-of-four nerve-stimulation pattern, and reversed, with intramuscular 0.01-0.045 mg/kg neostigmine and 0.01-0.02 mg/kg glycopyrronium, after the return of at least two out of four muscular twitches following nerve stimulation. Decrease in ABP and possibly hypothermia are likely intraoperative complications when clinical doses of atracurium are administered to pet rabbits. Measures should be taken to detect their occurrence in order to treat them promptly.