Combination Therapy
Pharmacokinetic Interactions Between Saquinavir, Zidovudine, Zalcitabine Appear Minimal
Pharmacokinetic interactions between saquinavir, zidovudine and zalcitabine are fairly insignificant, according to new data from the AIDS Clinical Trial Group protocol 229.
In ACTG 229, three combination therapeutic regimens--zidovudine plus either
saquinavir or zalcitabine or both--were studied in a phase II randomized
trial involving about 100 patients in each treatment arm. Dr. Terrence F.
Blaschke at California's Stanford University and coworkers there and at
other US sites, performed intensive pharmacokinetic studies...on
about 25 patients per arm at weeks 1 and 12.
The investigators report that no differences in pharmacokinetic parameters between
study weeks and arms emerged for any of the drugs, indicating little
interaction among them.
The investigators did discover that clearance of all three drugs decreased
with age. Weight did not affect zidovudine clearance, but it did correlate
positively with zalcitabine and saquinavir clearance.
Dr. Blaschke's group concluded, that there is no change in kinetics
with chronic administration and that there are no significant
pharmacokinetic interactions among these three drugs.