Pharmacokinetics and pharmacodynamics of Org NC 45

Org NC 45。一种非去极化肌肉松弛剂。作用时间较短，主要依靠肝脏代谢。潘库溴铵（Pancuronium bromide， PB）的用途最为广泛。但Org NC 45被认为是PB的替代品。18例患者采用1%安氟醚和60%氧化亚氮氧麻醉。9例患者给予0.05 mg/kg Org NC 45。其余9例患者均给予0.2 mg/kg的大剂量注射，通过测量拇内收肌的抽搐张力来监测大剂量注射对神经肌肉的影响。采用高效液相色谱法测定血浆中Org NC 45的浓度。小剂量组分布半衰期明显缩短，外周体积明显增大。与大剂量组比较。中央室几乎等同于循环血容量，稳态分布体积几乎等同于间质液体积。我们无法评价大剂量组药效学参数之间的关系。因为抽搐张力在给药后50分钟就完全被抑制了。小剂量组。每位患者的动力学参数与单次抽搐张力恢复25%、50%的时间无相关性。

Org NC 45. one of the non-depolarizing muscle relaxants. has shorter duration of action, and its metabolism is mainly depend on the liver. Pancuronium bromide (PB) is the most widely-used. but Org NC 45 is thought to take place of PB.Eghteen patients were anesthetized with 1% enflurane and 60% nitrous oxide in oxigen. Nine patients were given 0.05 mg/kg Org NC 45. and the other nine patients were given 0.2 mg/kg Org NC 45 as a bolus injection: The neuromuscular effect of Org NC 45 was monitored by measuring the twitch tension of adductor pollicis muscle. The plasma concentration of Org NC 45 was determined by high performance liquid chromatography. Small dose group had significantly smaller distribution half-life and larger peripheral volume. compared with large dose group. Central compartment was almost equivalent to circulating blood volume and steady state distribution volume was almost equivalent to interstitial fluid volume.We could not evaluate the relation between pharmacodvnamic parameters in large dose group. because twitch tension was completely depressed even at 50 min after the administration. In small dose group. there was no correlation between the kinetic parameters of each patient and the time to 25%, 50% recovery of the single twitch tension.