TABLE 3.

IC₅₀/K_i ratios for PIs

Drug	Ki (pg/ml)a	IC50,total (ng/ml)	IC50,free (ng/ml)	IC50,total/Ki ratio	IC50,free/Ki ratio
LPV	8.2 ± 3.9	17 ± 4b	0.69 ± 0.06c	2,070	84
RTV	154 ± 22	89 ± 14d	4.4 ± 0.8c	578	28
IDV	337 ± 69	23 ± 5e	NDf	68	NDf

^aK_i values were determined from a 13-point dose-response curve (see Materials and Methods). The numbers reported are means ± standard errors.

^bMean ± SD (n = 2).

^cMean ± SD (n = 4).

^dMean ± SD (n = 3).

^ePreviously determined IC₅₀ for wild-type HIV_IIIB in 10% FCS-containing culture medium (13).

^fND, not done.