The therapeutic drug monitoring of antidepressant drugs is of interest
to adapt dosage regimens to reduce the number of non-responder patien
ts, to reduce drug side effects and to detect noncompliant patients. A
therapeutic range is defined for many of these drugs and their linear
or non-linear kinetics are important parameters in clinical practice
to define the posology. Some patients, because of when there is drug b
iotransformation polymorphism, are exposed to drug accumulation a defi
cit in isoenzymes of cytochrome P450. The existence of these isoenzyme
s explains the possibility of non-linear kinetics and drug interaction
s.