Abstract
Critically ill patients require optimal pain control without undesirable side-effects. Continuous intravenous morphine infusion is often chosen instead of the conventional intermittent administration. In the present study, the pharmacokinetic characteristics of morphine were studied in five subjects receiving a constant rate intravenous infusion with the attainment of a steady state. The plasma levels were compared with values derived from bolus intravenous administration in five other patients. The concentrations of unchanged morphine were determined in serum using high performance liquid chromatography with an electrochemical detector. The decay of plasma concentrations after a single dose fitted a triexponential function consistent with a three compartment pharmacokinetic model. Postinfusion plasma concentrations fitted a two compartment model. Derived values (mean± sem) of total body clearance were significantly different between groups (p<0.05), while mean values of terminal elimination half-life ( t ½ Kel) were similar. It was concluded that values of total distribution volume were significantly different. The extent of morphine distribution varied more than twofold between the two groups of patients. This was interpreted as a consequence of an important underestimation in the extent of distribution to tissues after administration of a single dose.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
