Potency and hourly maintenance requirement of combinations of mivacurium and pancuronium in adults.
OBJECTIVE
To evaluate the dose-response and maintenance requirements of a combination of mivacurium and pancuronium (cMP) in clinical practice.


METHODS
In a randomised, open clinical study, 70 patients, 17-50 yr of age, were anaesthetised with propofol, alfentanil and nitrous oxide in oxygen. Thirty patients received mivacurium and 20 patients received pancuronium to establish dose-response curves for these agents. Hourly maintenance requirements of mivacurium and pancuronium to maintain 90-95% neuromuscular blockade (NMB) were determined. Thereafter, 20 additional patients received cMP in incremental doses to establish a cumulative dose-response curve for cMP followed by maintenance doses of cMP. NMB was recorded by adductor pollicis electromyography.


RESULTS
The ED95 values for mivacurium and pancuronium were 100 and 66 micrograms.kg-1, respectively; and for the cMP 2:1 (in mg:mg basis), 32 micrograms.kg-1 mivacurium together with 16 micrograms.kg-1 pancuronium. This cMP was 1.8 times more potent than one parent agent (P < 0.0001). When cMP 2:1 was used, 60% of normal maintenance requirement of pancuronium reduced the requirement of mivacurium by > 90%. If cMP 20:1 was used, then 20% of normal maintenance requirement of pancuronium reduced the requirement of mivacurium by > 70%. Neostigmine 35 micrograms.kg-1 given at T1 10% recovery following cMP reversed the NMB to a TOF ratio of 0.70 in 9.5 +/- 3.9 min.


CONCLUSIONS
These results reflect considerable synergism between mivacurium and pancuronium. The cMP is near intermediate-acting and the NMB is easily reversed with neostigmine. By using cMP, it may be possible to save some pharmacological costs during maintenance of anaesthesia.
Rautoma
P
P
Department of Anaesthesia, Maria Hospital of Helsinki City Hospital, Finland.
Erkola
O
O
Meretoja
O A
OA
D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004357:Drug Synergism; D006801:Humans; D007546:Isoquinolines / Q000008:administration & dosage*; D008875:Middle Aged; D000077590:Mivacurium; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage*; D010197:Pancuronium / Q000008:administration & dosage*; D013997:Time Factors
D004338:Drug Combinations; D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D000077590:Mivacurium; D010197:Pancuronium