Patients with compromised cardiovascular function who are undergoing cardiothoracic or other lengthy
surgical procedures are at risk of complications from the hemodynamic effects of the long-acting nondepolarizing
neuromuscular blocking agents (NMBs), which have been in use for several decades. The development of agents that maintain a stable hemodynamic profile is a potential advantage to this patient population. This literature review, which was completed in May 1992, describes the profiles of
doxacurium and
pipecuronium, two recently developed long-acting NMBs with increased potency over
d-tubocurarine,
metocurine, and
pancuronium.
Doxacurium is a benzylisoquinolinium compound with an ED95 of 0.025 mg/kg.
Pipecuronium, a steroidal agent, has an ED95 of 0.04 mg/kg. Twice the ED95 of either agent produces a duration of action comparable to that with 2 times ED95 of
pancuronium, but neither
doxacurium nor
pipecuronium possesses vagolytic or
histamine-releasing properties at therapeutic doses. Although no significant differences in serum elimination half-life or plasma clearance of
doxacurium have been noted between young and elderly patients, as with other NMBs, the duration of action of
doxacurium may be somewhat prolonged and seems to be more variable in older patients and in patients with impaired hepatic or renal function. A similar pattern appears to occur with
pipecuronium. Children seem to require higher doses of
doxacurium than adults to achieve the same degree of neuromuscular block but recover from the effects more rapidly.
Doxacurium and
pipecuronium produce no dose-dependent or clinically significant changes in heart rate, mean arterial pressure, or cardiac output either in patients with normal cardiac function or in those with
coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)