Carbamazepine level

Keywords: Tegretol


5 mL blood in lithium heparin or plain tube, collected immediately prior to the next dose.


Immunoassay, HPLC.

Therapeutic Interval:

20-40 µmol/L (6-12 mg/L).


Therapeutic drug monitoring.


Levels are related to the dose and the time since the previous dose.

Mean half-life is 35 h (range 18-65 h) early in treatment, often becoming shorter (12-24 h) with prolonged treatment due to enzyme induction by the drug (autoinduction).

Carbamazepine epoxide, a major metabolite, is also active pharmacologically. Its level may be available if analysis is done by HPLC.


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Glauser TA and Pippenger CE. Epilepsia. 2000; 41:6-15.