Pharmacokinetic studies in man with gallamine triethiodide. I. Single and multiple clinical doses.
Plasma concentrations of gallamine were determined in 6 patients undergoing anaesthesia for elective surgery receiving a single intravenous bolus dose of 2 mg/kg and in a further 11 patients requiring additional doses (0.5 to 2 mg/kg) of the relaxant. The two-compartment open model was found to characterize adequately both the single and multiple dose data. No significant differences were noted when the model-independent pharmacokinetic parameters between the two groups of patients were compared with the exception of the distribution phase half-life (t1/2 alpha) (6.70 min single vs 9.19 min multiple p less than 0.05). Mean values for the pooled data for the half-life (t1/2 beta), plasma clearance (Clp) and volume of distribution (Vd beta) were 134.58 min, 1.20 ml/min/kg and 225.28 ml/kg respectively. Evoked twitch response was monitored in each patient to assess the degree of neuromuscular blockade. In only one patient was the bolus dose sufficient to produce complete (100%) blockade, thus the degree of maximal response varied between 78 to 100% and took some 3 to 10 minutes after dose administration. The concurrently measured gallamine plasma concentrations ranged from 9.30 to 19.20 micrograms/ml. Linear regression of the offset data (20 to 80% paralysis) in 10 patients revealed a recovery rate of 0.35 to 1.33%/min. For 5 patients where offset data was available over the entire range of response (0 to 100%) the calculated mean effective plasma concentrations for gallamine at 50 and 95% paralysis (ECp50, ECp95) were found to vary between 3.43 to 10.28 micrograms/ml, and 5.66 to 23.37 micrograms/ml respectively.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005703:Gallamine Triethiodide / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D010243:Paralysis / Q000139:chemically induced; D013997:Time Factors
D005703:Gallamine Triethiodide