Table 5

Prediction of the in vivo interaction between metoprolol and paroxetine, based on in vitro substrate depletion experiments with (R)- and (S)-metoprolol in the absence and in the presence of 0.08 μM unbound paroxetine in the incubation mixture

SubstrateUnbound ParoxetineCLintPredicted AUC Ratio5-aObserved AUC Ratio5-b
μM μl/min/mg
(R)-Metoprolol03.94
0.081.57
2.510.5  (4.6–21.4)
(S)-Metoprolol02.54
0.081.48
1.76.7  (3.2–14.4)
  • 5-a  Calculated according to eq.8.

  • 5-b  In vivo observed AUC ratio (range) in the presence and in the absence of paroxetine (Hemeryck et al., 2000).