Ontogeny of CYP2C19 (S)-mephenytoin 4-hydroxylase metabolic activity
Age Bracket | Sample Size | %ND | Median-Specific Activitya | Specific Activity Rangea |
|---|---|---|---|---|
| pmol/min/mg | pmol/min/mg | |||
| Fetal | ||||
| 8-40 weeks | 64 | 55 | 1.3 | 0.1-345.5 |
| Postnatal | ||||
| 0 to 5 mo | 88 | 30 | 6.1 | 0.1-1516.5 |
| >5 mo to 10 yr | 52 | 12 | 22.4 | 0.1-656.5 |
| >10 yr to 18 yr | 19 | 0 | 18.5 | 0.4-101.7 |
↵ a Values for those samples that exhibited detectable activity.