Prediction of Propranolol Systemic Exposure Based on Heart-to-liver
radioactivity uptake ratio and Laboratory Tests
Abstract
BACKGROUND/AIM: Propranolol is a beta-adrenergic receptor blocker which
is used for the treatment of portal hypertension in patients with liver
cirrhosis. The systemic exposure of propranolol may vary according to
the extent of portal hypertension and liver function. The objective of
this study was to propose a model for predicting the exposure of
propranolol. METHODS: Thirty normal subjects, 18 patients with chronic
active hepatitis (CAH), and 54 patients with cirrhosis were included in
this study. Blood samples for pharmacokinetic analysis were taken up to
8 hours post-dose. Pharmacokinetic analysis was performed using a
non-compartmental model. The extent of portal hypertension was evaluated
by heart-to-liver radioactivity uptake ratio (H/L ratio) using 201TI per
rectal scintigraphy. A multivariate regression analysis was performed to
determine the best model for estimating the Cmax or AUC of propranolol.
RESULTS: Twenty-four normal subjects, 18 CAH patients, and 36 cirrhosis
patients completed the study. A multivariate stepwise linear regression
analysis revealed that sex, weight, total bilirubin concentrations,
platelet counts, and H/L ratio affected the exposure of propranolol:
Cmax (ng/mL) = 50.976-18.743×sex[M:1;F:0]-0.408×weight+6.155×total
bilirubin+35.328×H/L ratio (adjusted r2=0.440); AUClast (ng·h/mL) =
298.86–71.080×sex[M:1;F:0]–2.158×weight–0.312×platelet
count+26.372×total bilirubin+176.745×H/L ratio (adjusted r2=0.500).
CONCLUSION: A multivariate model based on laboratory tests, H/L ratio,
body weight, and sex can predict the systemic exposure of propranolol
and thereby inform the prescription of propranolol in patients with
liver disease.