Figure 4.
Inhibitory potential of three drug combinations. (a) Estimated IIPave1+2+3 for triple combinations of 19 commonly used antiretroviralss. Combinations are color coded by drug class, excluding combinations with more than one drug from the NNRTI, PI, or InSTI classes, or NRTI subclasses. The black bars represent the range of estimated IIPave1+2+3 values with the Loewe prediction at the left and the Bliss prediction at the right. Regimens are sorted based on the midpoint of the range. An estimate based on the weighted average of the three pairwise DI index values is shown as a green dot. IIPave1+2+3 values above the Loewe-Bliss range represent synergy, typically for regimens including thymidine analogues. The red line represents the minimum IIPave1+2+3 for a regimen achieving suppression of viremia in > 80% of patients. (b) Inhibitory potential of selected three drug combinations along with component single drugs and drug pairs. For combinations, inhibitory potential is shown as a range of IIPave1+2+3 values between the Loewe and Bliss predictions. For each component two drug combination, an estimate of IIPave based on experimentally determined DI index values is shown as a green bar. For three drug combinations, green bars represent estimates based on a weighted average of pairwise DI index values. Values are shown for currently recommended initial HAART regimens10,11 and, for purposes of comparison, a suboptimal TDF+3TC+ABC regimen37.