Back to the Top
The following message was posted to: PharmPK
We are trying to conduct a QTc prolongation study using ritonavir 100
mg or ketoconazole 400 mg at single doses to achieve the
supratherapeutic dose levels. Does anyone have experience with such
a study and how long it would take to wash out the PK and QT effects
of these drugs? The half-life of our drug is short.
Also, do these drugs have QT prolongation effects of their own? I
have found conflicting data in the literature.
Thanks,
Vernon
Back to the Top
The following message was posted to: PharmPK
Hi Vernon:
We have found zero indication of QTc prolongation in rats or guinea pigs
in crossover studies in which they were dosed with ketoconazole up to 10
mg/kg by intragastric catheter. All subjects were conscious and
freely-moving and EKGs were acquired every 5 seconds for up to 4 hours
postdose.
Of course, the sitation changes when you codose with terfenadine.
Terfenadine has no effect by itself in rats (same dose, same route, same
crossover studies), but it triggers significant anomalies in guinea pigs
when dosed alone.
Sincerely,
Candice Kissinger
Senior V.P. Research
BASi
PharmPK Discussion List Archive Index page
Copyright 1995-2010 David W. A. Bourne (david@boomer.org)