Absence of a pharmacokinetic interaction between digoxin and levofloxacin.
BACKGROUND
Levofloxacin, a broad-spectrum fluoroquinolone, may enhance digoxin bioavailability by eliminating intestinal flora that metabolize digoxin. Moreover, levofloxacin, which is eliminated primarily by glomerular filtration and active tubular secretion, may alter the elimination rate of digoxin. Because of the narrow therapeutic index of digoxin, it is important to evaluate the potential for interaction with levofloxacin when administered concomitantly.


METHODS
This was a placebo-controlled, randomized, double-blind, two-phase crossover study. Twelve healthy subjects (six males and six females) received 500 mg twice/day oral doses of levofloxacin or placebo for 6 days and a single oral dose of 0.4 mg digoxin on the morning of study day 5 along with levofloxacin or placebo.


RESULTS
There was no significant effect of levofloxacin on the pharmacokinetics (Cmax, AUC, and other disposition parameters) of oral digoxin. Steady-state levofloxacin absorption and disposition kinetics were also similar in the presence or absence of digoxin.


CONCLUSIONS
Results of this study suggest that an important pharmacokinetic interaction between levofloxacin and digoxin is unlikely to occur when administered concomitantly.
Chien
S C
SC
Johnson & Johnson Pharmaceutical Research & Development, L.L.C., Raritan, NJ 08869, USA.
Rogge
M C
MC
Williams
R R
RR
Natarajan
J
J
Wong
F
F
Chow
A T
AT
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000890:Anti-Infective Agents / Q000009:adverse effects / Q000494:pharmacology*; D019540:Area Under Curve; D001682:Biological Availability; D018592:Cross-Over Studies; D004077:Digoxin / Q000493:pharmacokinetics*; D004311:Double-Blind Method; D004347:Drug Interactions; D005260:Female; D006801:Humans; D007700:Kinetics; D064704:Levofloxacin; D008297:Male; D008875:Middle Aged; D015242:Ofloxacin / Q000009:adverse effects / Q000494:pharmacology*; D010919:Placebos
D000890:Anti-Infective Agents; D010919:Placebos; D064704:Levofloxacin; D004077:Digoxin; D015242:Ofloxacin