Lamotrigine therapeutic range

Use standard therapeutic serum concentration ranges if clinically indicated if partial response or breakthrough episode, adjust dose to achieve higher serum concentrations without causing intolerable adverse effects valproate is preferred over lithium for mixed episodes and rapid cycling lithium and/or lamotrigine is preferred over valproate for bipolar depression. 

Target plasma levels A therapeutic plasma concentration range has not been established for lamotrigine. Base dosing of lamotrigine on therapeutic response. Adjustments to the maintenance dose of lamotrigine ... 

A 1-ml portion of plasma was extracted twice (pH 7.4 and 12] using a 1 1 mbcture of diethyl ether and ethyl acetate after addition of methaqualone as internal standard. The extract was analyzed by GC-MS in the selective-ion monitoring (SIM) mode (m/z 185, 187, 255, 257 for lamotrigine and 235, 250 for methaqualone). A five-point calibration graph was established using spiked plasma samples [65]. The procedure was linear from 0.5 to 20 mg/L (r = 0.991) with coefficients of variation of less than 15%. The LOD was 0.1 mg/L. As we have seen, therapeutic concentrations ranged from 1 to 6 mg/L. The presented method has proved to be suitable for TDM as well as for clinical toxicology. 

The linearity of the quantitation was tested for the practical application of a fast OPC approach with levels in the practical range from high therapeutic up to toxic plasma concentrations, typically comprising 0.1, 0.5, 2, 4 and 6 mg/L. Exceptions are the highly dosed drugs such as levetiracetam, lamotrigine, phenprocoumon or quetiapine (see Table 4.58). 

---