TABLE 4.
Equipotent ratio (fold of EC50a) of GCV/PCZ | CIb | Drug combination effectc |
---|---|---|
0.25 | 0.625 ± 0.169 | Synergism |
0.5 | 0.780 ± 0.031 | Moderate synergism |
1 | 0.353 ± 0.278 | Synergism |
2 | 0.075 ± 0.039 | Very strong synergism |
4 | 0.064 ± 0.042 | Very strong synergism |
Fold increase of the EC50 for GCV/PCZ yielding an equipotent concentration ratio between the two combined drugs. The EC50s were determined by PRAs against HCMV AD169 in HFFs for each drug alone or in combination at concentrations from 4-fold to 0.25-fold the equipotent ratio of the drugs, using a ratio of 1:1.33, approximated from values in Table 1.
Combination index, obtained by computational analysis with Calcusyn software. Values are means ± SD of data derived from 3 independent experiments in triplicate.
Effects are defined as follows: CI < 0.1, very strong synergism; 0.1 < CI < 0.3, strong synergism; 0.3 < CI < 0.7, synergism; 0.7 < CI < 0.9, moderate synergism (32).