Table 1.
Geometric mean (SD) pharmacokinetic parameters (n = 16) and statistical comparisons (ratios [90% CI]) for lamotrigine (LTG), ethinyloestradiol and levonorgestrel after administration of lamotrigine (300 mg) alone and with the combined oral contraceptive (COC)
| Effect of COC on lamotrigine (LTG) | |||
|---|---|---|---|
| LTG + COC | LTG | Ratio LTG + COC : LTG [90% CI] | |
| Lamotrigine | |||
| Cmax (µg ml−1) | 6.33 (1.43) | 10.3 (1.91) | 0.61 [0.57, 0.66] |
| AUC(0,24 h) (µg ml−1 h) | 78.8 (31.0) | 163 (42.7) | 0.48 [0.44, 0.53] |
| Effect of lamotrigine (LTG) on COC | |||
|---|---|---|---|
| LTG + COC | COC | Ratio LTG + COC : COC [90% CI] | |
| Ethinyloestradiol | |||
| Cmax (pg ml−1) | 91.7 (37.1) | 89.5 (35.1) | 1.02 [0.95, 1.10] |
| AUC(0,24 h) (pg ml−1 h) | 785 (267) | 849 (265) | 0.93 [0.88, 0.97] |
| Levonorgestrel | |||
| Cmax (pg ml−1) | 6886 (1797) | 7858 (2393) | 0.88 [0.82, 0.93] |
| AUC(0,24 h) (pg ml−1 h) | 79981 (21605) | 98653 (33157) | 0.81 [0.76, 0.86] |