Drug–drug combinations.
| Drug combination | CI valuesa at inhibition of | Weighted average CI valuesb | Assigned symbolc | Description | |||
|---|---|---|---|---|---|---|---|
| 50% | 75% | 90% | 95% | ||||
| Belinostat + bortezomib | 0.488 | 0.410 | 0.344 | 0.305 | 0.36 | +++ | Synergism |
| 7f + bortezomib | 0.572 | 0.359 | 0.225 | 0.164 | 0.26 | ++++ | Strong synergism |
a
CI values are based on the combination index isobologram equations: CI = [(D)1/(Dx)1] + [(D)2/(Dx)2], where Dx = Dm[fa/(1 − fa)]1/m.
b
Because the high degrees of effects are more important than the low degrees of effects, the weighted CI value was designed as: CIwt = [CI50 + 2CI75 + 3CI90 + 4CI95]/10.
c
Degree of synergism or antagonism are based on the ranges of CI values as described in Pharmacological Reviews.27