Table 3.
DPD status category according to UH2/U ratio value and subsequent dose tailoring.
| DPD status | UH/U ratio | Theoretical adaptative dosing | |
|---|---|---|---|
| Extensive metabolizers (EM) | > 4 | Standard 5-FU dosing | |
| Poor metabolizers (PM) | Grey-zone patients | [3 – 4] | Alert for reduced activity, without systematic dose reduction |
| mildly DPD deficient | ]2 – 3[ | 20% dose reduction | |
| intermediary DPD deficient | ]1 – 2] | 30% dose reduction | |
| profoundly DPD deficient | ]0.5 – 1] | 50% dose reduction | |
| completely DPD deficient | < 0.5 or UH2 not detectable upon HPLC analysis | 5-FU precluded | |