Figure 3

Variation of total phenytoin, adjusted phenytoin, and free phenytoin with respect to plasma albumin concentration. (A) Variation of the difference between PHT_total/10 and PHT_free with respect to plasma albumin concentration. All data is from chronologically first phenytoin measurements in 756 patients. The dashed line is from linear regression: [PHT_total/10 - PHT_free] = -2.136 + 0.477 * [albumin concentration] (R² = 0.19). The 95% confidence intervals of the intercept is (-2.37, -1.90) and for the slope is (0.406, 0.549). (B) Variation of the difference between PHT_free and PHT_{adj_free} with respect to plasma albumin concentration using same source of patient data in (A). The dashed line is from linear regression: [PHT_free - PHT_{adj_free}] = 0.0838 + 0.0021*[plasma albumin] (R² = 0.004). The 95% confidence intervals of the intercept is (-0.138, 0.305) and for the slope is (-0.0649, 0.0691)