Table 2.
The pharmacokinetic parameters for nifedipine (NIF) and dehydronifedipine (DNIF) in the study population (n = 10)
| Tmax (h) | Cmax (µg l−1) | t1/2β (h) | MRT(h) | AUC0–t (µg l−1 h−1) | AUC0–∞ (µg l−1 h−1) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Haplotype | Before SJW | After SJW | Before SJW | After SJW | Before SJW | After SJW | Before SJW | After SJW | Before SJW | After SJW | Before SJW | After SJW | F (%) |
| NIF | |||||||||||||
| H1/H2 (n = 4) | 1.5 ± 0.7 | 1.3 ± 0.3 | 34.3 ± 13.0 | 22.7 ± 5.4* | 8.5 ± 4.4 | 7.4 ± 0.8 | 6.1 ± 0.4 | 5.0 ± 1.0 | 209.5 ± 32.6 | 112.2 ± 31.0* | 231.7 ± 47.7 | 133.4 ± 28.0* | 53.0 ± 8.0 |
| H2/H2 (n = 3) | 1.5 ± 0.0 | 1.5 ± 0.0 | 53.2 ± 6.3 | 30.8 ± 4.2* | 7.4 ± 2.7 | 4.8 ± 1.7 | 6.8 ± 1.0 | 5.8 ± 1.2 | 332.6 ± 76.4 | 183.9 ± 49.9* | 370.3 ± 102.5 | 193.0 ± 52.6* | 54.9 ± 3.1 |
| H1/H1 (n = 3) | 1.8 ± 0.6 | 1.8 ± 0.6 | 59.3 ± 13.2 | 33.2 ± 5.5* | 7.0 ± 1.7 | 9.5 ± 2.0 | 6.7 ± 0.9 | 7.6 ± 1.1 | 409.8 ± 176.2 | 268.4 ± 99.2* | 453.4 ± 221.1 | 322.1 ± 145.6* | 66.7 ± 4.4 |
| Total (n = 10) | 1.6 ± 0.5 | 1.5 ± 0.4 | 47.5 ± 15.4 | 28.3 ± 6.6* | 7.7 ± 3.0 | 7.2 ± 2.3 | 6.5 ± 0.8 | 6.0 ± 1.5 | 306.5 ± 128.5 | 180.6 ± 87.8* | 339.8 ± 154.2 | 207.9 ± 111.7* | 57.7 ± 8.2 |
| DNIF | |||||||||||||
| H1/H2 (n = 4) | 1.8 ± 0.5 | 1.6 ± 0.7 | 23.8 ± 6.8 | 39.5 ± 11.7* | 4.5 ± 1.3 | 4.3 ± 1.0 | 4.2 ± 0.5 | 4.0 ± 0.5 | 124.8 ± 36.6 | 155.7 ± 48.1* | 136.0 ± 35.0 | 163.6 ± 48.7* | – |
| H2/H2 (n = 3) | 1.8 ± 0.6 | 1.3 ± 0.3 | 21.0 ± 1.9 | 31.1 ± 2.4* | 4.2 ± 2.2 | 4.1 ± 1.7 | 5.1 ± 1.3 | 4.5 ± 0.7 | 105.1 ± 13.1 | 140.4 ± 16.0* | 111.2 ± 13.8 | 147.9 ± 22.3* | – |
| H1/H1 (n = 3) | 1.7 ± 0.8 | 1.8 ± 0.6 | 17.8 ± 5.8 | 36.4 ± 11.0* | 4.5 ± 0.9 | 5.1 ± 0.6 | 4.8 ± 1.6 | 5.2 ± 1.1 | 94.6 ± 59.5 | 197.9 ± 80.9* | 100.2 ± 62.1 | 207.1 ± 82.8* | – |
| Total (n = 10) | 1.8 ± 0.5 | 1.6 ± 0.6 | 21.2 ± 5.6 | 36.1 ± 9.3* | 4.4 ± 1.3 | 4.5 ± 1.1 | 4.7 ± 1.1 | 4.5 ± 0.9 | 109.8 ± 38.2* | 163.8 ± 53.7* | 117.8 ± 39.7 | 171.9 ± 55.3* | – |
*
P < 0.05, before vs. after SJW administration. Tmax, time to maximum plasma concentration; Cmax, peak concentration; t1/2β, elimination half-life; MRT, mean residence time; AUC0–t, area under concentration–time curve up to the last measured time point; AUC0–∞, AUC0–t extrapolated to infinity; F, relative bioavailability of NIF before and after oral administration of SJW, obtained by (AUC0–t after SJW/AUC0–t before SJW) × 100%; SJW, St John's wort.