Hepatic function monitoring

Vulnerability of the liver to injury necessitates routine evaluation of hepatic function in patients and asymptomatic individuals to avert or control adverse clinical conditions. Thus, a plethora of methods has been developed for the diagnosis of liver diseases and dysfunctions. One such method uses physical palpation to determine alterations or changes in the orientation of the liver, which provides valuable information about the organ status but the quality of information is subjective and imprecise [3]. Another common method for the diagnosis of more serious hepatic injuries involves liver biopsies coupled with biochemical tests to determine the extent of liver injury and prognosis [4-7]. However, in acute and some chronic hepatic disorders, dynamic and continuous hepatic function monitoring would be advantageous. 

Dynamic Hepatic Function Monitoring with Exogenous Organ-Specific Ciearance Markers... 

Although several markers for functional hepatic mass determination are currently used in clinical settings, most of them were originally used as drugs for various medical interventions. Nonetheless, these markers remain the mainstay of dynamic hepatic function monitoring, some of which are discussed below. 

Markers for Dynamic Hepatic Function Monitoring by Microsomal Enzyme Activity... 

MEGX is readily detected by HPLC and fluorescence polarization immunoassay techniques [14,21,25,40,41]. The test is simple, normally requiring a onetime blood sampling, and informative because it depends on the capacity of the hepatic enzymes to metabolize lidocaine. While the analysis of lidocaine metabolites is rapid, this method has not been adapted for continuous hepatic function monitoring, which may be possible with the radiolabeled analogues such as Tc-Sn-lidocaine iminodiacetic acid [42]. 

In addition to hepatic blood flow and function, ICG plasma clearance is also a useful prognostic factor for selecting patients for hepatectomy [1311. A majority of model systems developed for continuous hepatic function monitoring rely on the clearance profile of indocyanine green (ICG), which is the primary focus of this section. 

Invasive continuous hepatic function monitoring by the fluorescence procedure was also evaluated in rabbits [148]. In this study, a commercial catheter equipped with fiber optic technology for mixed venous oxygen saturation measurements (SVO2) was modified to emit light at 780 nm and detect fluorescence at 840 nm. The catheter was placed into the right jugular vein and advanced... 

Hepaticaiiy impaired patients For patients with moderate hepatic impairment, an initial dose of 0.5 mcg/kg/min is recommended, based on the approximate 4-fold decrease in argatroban clearance relative to those with normal hepatic function. Monitor the aPTT closely and adjust the dosage as clinically indicated. 

Hepatic function - Monitor patients who discontinue adefovir at repeated intervals over a period of time for hepatic function. If appropriate, resumption of... 

CALCIUM CHANNEL BLOCKERS SIROUMUS Plasma concentrations of sirolimus are t when given with diltiazem. Plasma levels of both drugs are t when verapamil and sirolimus are coadministered Diltiazem and verapamil inhibit intestinal CYP3A4, which is the main site of sirolimus metabolism Watch for side-effects of sirolimus when it is co-administered with diltiazem or verapamil monitor renal and hepatic function. Monitor PR and BP closely when sirolimus is given with verapamil... 

Of 23 reported cases of hepatic failure, only 10 (includ-ing 5 who died) were considered to be probably related to the drug (7,14). There have also been 20 cases of hepatitis in which no deaths occurred in five of these a relation to felbamate was unlikely. Overall the incidence of fatal liver toxicity is estimated at 1 per 26 000-34 000. A careful history of past hepatic toxicity with other drugs should be taken and liver function tests are recommended before starting felbamate. Patients should have hepatic function monitored regularly and should be alerted to the signs and symptoms of hepato-toxicity. 

---