title: Comparative evaluation of the effects of labetalol, verapamil and diltiazem on antipyrine and indocyanine green clearances.
abstract: The effects of labetalol, diltiazem and verapamil on antipyrine and indocyanine green clearance were evaluated in a placebo-controlled, repeated measures evaluation. Twelve healthy subjects received either labetalol (200 mg every 12 hours), diltiazem (90 mg. every 8 hours), verapamil (80 mg every 8 hours), or placebo (every 12 hours) for 4 days. On the morning of Day 3 immediately following their dose, the subjects assumed the supine position for 90 minutes, after which time a 0.5 mg/kg dose of indocyanine green was administered. Blood samples were obtained serially over a 20 minutes period for indocyanine green plasma concentration determinations by HPLC. Ten minutes later, subjects ingested a 1.2 Gm. dose of antipyrine and blood samples were obtained over a 48 hour period for antipyrine plasma concentration determinations by HPLC. A 2 week washout period separated treatment sequences. Mean (SD) antipyrine clearance (L/hr/kg) following diltiazem [0.028 (0.010)] and verapamil [0.030 (0.012)] treatment was significantly lower than that observed following placebo [0.039 (0.012)]. Antipyrine clearance following labetalol administration [0.033 (0.010)] was not significantly different from that observed following placebo, diltiazem or verapamil administration. No effects of these drugs on indocyanine green clearance could be detected.
authors.affiliation: Division of Clinical Pharmacology, Jefferson Medical College, Philadelphia, PA.
authors.forename: M L
authors.initials: ML
authors.lastname: Rocci
authors.forename: P H
authors.initials: PH
authors.lastname: Vlasses
authors.forename: M E
authors.initials: ME
authors.lastname: Lener
authors.forename: R A
authors.initials: RA
authors.lastname: Fruncillo
authors.forename: M A
authors.initials: MA
authors.lastname: Sirgo
mesh_terms: D000328:Adult; D000983:Antipyrine / Q000378:metabolism*; D004110:Diltiazem / Q000494:pharmacology*; D006207:Half-Life; D006801:Humans; D007208:Indocyanine Green / Q000378:metabolism*; D007741:Labetalol / Q000494:pharmacology*; D008297:Male; D011897:Random Allocation; D014700:Verapamil / Q000494:pharmacology*
chemical_list: D014700:Verapamil; D004110:Diltiazem; D007208:Indocyanine Green; D007741:Labetalol; D000983:Antipyrine