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Verapamil pharmacokinetics and apparent hepatic and renal blood flow.
Author(s) -
Meredith PA,
Elliott HL,
Pasanisi F.,
Kelman AW,
Sumner DJ,
Reid JL
Publication year - 1985
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1111/j.1365-2125.1985.tb05038.x
Subject(s) - verapamil , pharmacokinetics , renal blood flow , medicine , dosing , renal function , blood flow , effective renal plasma flow , pharmacology , endocrinology , calcium
The effect of acute and continued administration of verapamil on pharmacokinetics and regional blood flow has been studied in eight normotensive subjects. Continued administration resulted in a significant decrease in verapamil clearance, compared to that following acute dosing, as assessed by increases in both terminal elimination half‐life (from a mean +/‐ s.d. of 5.2 +/‐ 2.3 h to 6.7 +/‐ 2.0 h) and AUC (from a mean +/‐ s.d. of 800 +/‐ 353 ng ml‐1 h to 1455 +/‐ 244 ng ml‐1 h). The relative clearance of norverapamil was not changed. Acute administration of verapamil resulted in a significant increase (P less than 0.005) in apparent liver blood flow which with continued administration fell significantly (P less than 0.01) towards placebo values. Effective renal plasma flow similarly increased with acute verapamil administration (P less than 0.05) and with chronic administration reduced again to be not significantly different from placebo. Acute and chronic verapamil administration did not significantly alter glomerular filtration rates. These results suggest that there may be a relationship between the acute increase in liver blood flow and the relatively increased clearance of verapamil following acute dosing.