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VOL. 70 (3), 663-679, 2004 PHARMACOKINETICS AND INDIVIDUALIZED DRUG THERAPY

it will take almost half a year before you know if the prescribed dose
will end with a plasma concentration within the desired concentra-
tion range. In Fig. 12 is shown a woman who got 2 ml injected every
second week and the first sample taken during the first dose was
within the therapeutic range, but a Bayesian estimate showed that if
the patient continues with this dosing scheme it will lead too high
plasma concentrations that will be evident three months later.

FIGURE 12. A patient treated with perphenazin depot injections (2mL every second
week) and a plasma concentration value taken during the first dose being within
the therapeutic drug concentrations. However, this drug dosing will lead to drug

levels above the therapeutically recommended.

As illustrated in Fig. 13, this patient should only be given 0,5 mL
every second week in order to keep the plasma concentrations within
the therapeutic range.

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