Table 3.
Effects of the CYP2C19 and CYP2C9 genotypes on standardised VPA concentrations in the patients with epilepsy
| Genotypes | N (%) | Mean age (years) |
Mean VPA dose (mg/kg per day) |
Mean VPA concentration (μg/mL) |
CDRV (μg·kg/mL·mg) |
P value |
| CYP2C19 G681A/ G636A | ||||||
| EMs* | 37 (44.6%) | 50.70±17.91 | 16.28±7.50 | 48.73±24.08 | 3.33±1.78 | EMs vs IMs p=0.013§ EMs vs PMs p=0.000§ IMs vs PMs p=0.000§ |
| IMs† | 33 (39.8%) | 48.73±19.05 | 12.80±5.02 | 57.15±25.07 | 4.45±1.42 | |
| PMs‡ | 13 (15.6%) | 51.15±24.62 | 11.54±3.12 | 75.55±25.58 | 6.64±1.06 | |
| CYP2C9 T269C | ||||||
| Non-carriers¶ | 75 | 49.72±22.98 | 14.14±6.50 | 56.21±26.40 | 4.08±1.97 | p=0.809†† |
| Carriers** | 8 | 52.50±17.17 | 14.25±4.52 | 56.92±24.64 | 3.91±0.99 | |
*EM: extensive metaboliser genotype: CYP2C19 *1/*1.
†IM intermediate metaboliser genotype: CYP2C19 *1/*2 (n=31) and CYP2C19 *1/*3 (n=2).
‡Poor metabolizer genotype: CYP2C19 *2/*2 (n=11), CYP2C19 *3/*3 (n=1) and CYP2C19 *2/*3 (n=1).
§Games–Howell test, mean difference is significant at the 0.05 level.
¶Non-carriers: CYP2C9*1/*1.
**Carriers: *1/*13 (n=7) and *13/*13 (n=1).
††Independent sample t-test, mean difference is significant at the 0.05 level.
EMs, extensive metabolisers; IMs, intermediate metabolisers; PMs, poor metabolisers; VPA, valproic acid.