The acute and chronic effects of H1 receptor blockade with astemizole on indocyanine green clearance.
The effects of acute and chronic (3 months) dosing with astemizole on indocyanine green kinetics have been investigated in normal volunteers and patients. A single dose of astemizole 40 mg produced significant reduction in indocyanine green clearance (P less than 0.02) and volume of distribution (P less than 0.02) when assessed at 48 h, but not at 24 h. In six volunteers who did not receive astemizole there was no significant change in indocyanine green kinetics over a 48 h period. In seven patients on chronic treatment with astemizole there was no significant change in indocyanine green kinetics when these were measured at 1 month and 3 months and compared to pre-treatment values. The change in indocyanine green clearance and volume of distribution following acute astemizole treatment did not correlate with H1-receptor antagonism. Change in indocyanine green clearance following acute drug administration may not be due to changes in liver blood flow and should therefore be interpreted with caution.
D000328:Adult; D016589:Astemizole; D001562:Benzimidazoles / Q000494:pharmacology*; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D006801:Humans; D007208:Indocyanine Green; D007700:Kinetics; D008102:Liver Circulation / Q000187:drug effects*; D008297:Male; D008657:Metabolic Clearance Rate / Q000187:drug effects
D001562:Benzimidazoles; D006634:Histamine H1 Antagonists; D016589:Astemizole; D007208:Indocyanine Green