EFFECT OF DIALYSIS ON EXOGENOUS DOPAMINE IN HEMODIALYZED CRITICALLY ILL PATIENTS

A sensitive and specific high performance liquid chromatographic metho d (HPLC) was developed for measuring dopamine (DA) in human plasma sam ples. Dihydroxybenzylamine (DHBA) was employed as an internal standard . Following solvent extraction and separation on a C-18 ion-pairing re versed phase column, the drug was detected by a fluorescence detector with excitation and emission wavelengths of 233 nm and 345 nm, respect ively. This method was employed to evaluate dopamine dialysability in seven haemodialysed patients under continuous infusion of a positive i notropic agent. Results showed a high dialyser extraction ratio averag ing 38 . 3%, but a low dialysis clearance of 67 ml/min. The fraction r emoved by dialysis is 2 . 5%. We concluded that haemodialysis has litt le effect on dopamine blood levels, and consequently on drug pharmacok inetics, when the drug is delivered to haemodialysed patients under in travenous infusion.