Association between levobupivacaine and pancuronium. Interference in neuromuscular transmission and blockade in rats

Abstract

PURPOSE:To evaluate the effects of levobupivacaine on neuromuscular transmission and neuromuscular blockade produced by pancuronium in vitro. METHODS:Thirty rats were distributed into groups (n = 5) according to the drug used alone or in combination: Group I -levobupivacaine (5 µg.mL-1 ); Group II -pancuronium (2 µg.mL -1 ); Group III -pancuronium (2 µg.mL -1 ) + levobupivacaine (5µg.mL -1 ). The following parameters were evaluated: 1) amplitude of diaphragmatic response to indirect stimulation, before and 60 minutes after the addition of levobupivacaine and pancuronium alone, and after the addition of levobupivacaine combined with pancuronium; 2) membrane potentials (MP) and miniature endplate potentials (MEPP). RESULTS:Levobupivacaine alone did not alter the amplitude of muscle response and MP. In preparations previoulsy exposed to levobupivacaine, the block with pancuronium was significantly denser (90.2 ± 15.2%), showing a significant difference (p=0.031) in comparison to the block produced by pancuronium alone (48.9% ± 9.8%). There was a decrease in the frequency and amplitude of MEPPs. CONCLUSION:Levobupivacaine potentiated the neuromuscular blockade produced by pancuronium, confirming a presynaptic action by a decrease in miniature endplate potentials.

Onset and duration of cis‐atracurium neuromuscular block during fentanyl and lidocaine infusions in isoflurane‐anaesthetised dogs

“…Lidocaine was described to increase the sensitivity to cis-atracurium on rats in vitro 21 and in vivo 30. This effect was associated with interactions of local anaesthetics with presynaptic and postsynaptic nicotinic receptors in the neuromuscular junction, which would affect ion transport and produce a muscle membrane stabilisation effect 10 21 31 32. Such mechanism would result on a decrease in the onset7 24 and an increase in the duration and potency of NMB drugs 8 9 33.…”

“…NMBAs can be potentiated by some drugs, such as systemic local anaesthetics7–10 and opioid mu agonists,11–15 which can decrease the onset and increase the duration of the NMB. In dogs, these drugs provide intraoperative analgesia and an anaesthetic-sparing effect16 17 that is beneficial to minimise the potential hypotensive effect induced by anaesthetic agents 6.…”

“…6 Hypotension following cis-atracurium administration in dogs is not well described, and it remains unknown whether it actually plays a role in the incidence of hypotension in this animal species. 1 NMBAs can be potentiated by some drugs, such as systemic local anaesthetics [7][8][9][10] and opioid mu agonists, [11][12][13][14][15] which can decrease the onset and increase the duration of the NMB. In dogs, these drugs provide intraoperative analgesia and an anaesthetic-sparing effect 16 17 that is beneficial to minimise the potential hypotensive effect induced by anaesthetic agents.…”