Invasive pharmacodynamic characterization of combined ibopamine and calcium blocker therapy for heart failure.
OBJECTIVE
To determine the acute hemodynamic response of single-dose coadministration of ibopamine plus nifedipine or diltiazem in patients with New York Heart Association functional class (NYHA FC) II-III congestive heart failure.


METHODS
A single-blind, placebo-controlled, two-paired, crossover study.


METHODS
Cardiology clinics at two large teaching hospitals.


METHODS
Eight patients with NYHA FC II-III congestive heart failure who met the inclusion criteria were selected randomly.


METHODS
All patients underwent right heart catheterization. Day 1 consisted of concomitant calcium channel blocker plus placebo, with cardiac and peripheral hemodynamic recordings from 30 minutes-24 hours. The design was equivalent on day 2, with single-dose administration of ibopamine plus calcium channel blocker.


RESULTS
Single-dose nifedipine-diltiazem augmented cardiac output and stroke volume secondary to decreasing systemic vascular resistance. The nifedipine-ibopamine and diltiazem-ibopamine subgroups demonstrated relatively equal hemodynamics, augmenting cardiac index (nifedipine 43%, p < 0.05; diltiazem 40%, p < 0.05 vs baseline) while decreasing systemic vascular resistance (nifedipine 41%, p < 0.05; diltiazem 28%, p NS vs baseline) 30 minutes after the dose. In contrast to single-dose diltiazem, the diltiazem-ibopamine subgroup exhibited an increased left ventricular filling pressure (122%, p < 0.05 vs baseline) and mean pulmonary artery pressure (43%, p < 0.05 vs baseline) at 30 minutes after the dose. One patient experienced a transient episode of chest pain associated with increased heart rate and blood pressure with diltiazem-ibopamine.


CONCLUSIONS
Diltiazem and ibopamine should be coadministered with caution in patients with coronary artery disease and left ventricular dysfunction.
Munger
M A
MA
Department of Pharmacy Practice, University of Utah, Salt Lake City 84112.
Nara
A R
AR
Pospisil
R A
RA
Stoddard
G J
GJ
Schleman
M
M
D000328:Adult; D000368:Aged; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000494:pharmacology*; D003846:Deoxyepinephrine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004110:Diltiazem / Q000008:administration & dosage / Q000494:pharmacology; D015259:Dopamine Agents / Q000008:administration & dosage / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage / Q000494:pharmacology; D016037:Single-Blind Method
D002121:Calcium Channel Blockers; D015259:Dopamine Agents; C023487:ibopamine; D004110:Diltiazem; D009543:Nifedipine; D003846:Deoxyepinephrine