Serum protein binding of desmethyl-methsuximide.

Serum protein binding of desmethyl-methsuximide (DM-MSM) in serum from 23 patients on polytherapy were determined using ultrafiltration and high-performance liquid chromatography. Desmethyl-methsuximide, The active metabolite of methsuximide (MSM), was found to have a moderate protein binding ranging between 45% and 60%.

Sensitive high-performance liquid chromatographic method with fluorometric detection for the simultaneous determination of gabapentin and vigabatrin in serum and urine.

Serum concentrations of the antiepileptic drug gabapentin (GBP) are usually determined by high-performance liquid chromatography (HPLC) using UV photometric detection after pre-column derivatization with 2,4,6-trinitrobenzenesulphonic acid. Vigabatrin levels in serum are determined by HPLC using fluorescence detection. Like vigabatrin (VGB), gabapentin has also a primary amine group that easily reacts with o-phthaldialdehyde reagent and produces a fluorescing substance.

Carbamazepine: detection of another metabolite in serum, 9 hydroxymethyl-10-carbamoyl acridan.

In this article, the authors discuss 9-hydroxymethyl-10-carbamoyl acridan (9-OH-CBZ), another metabolite of carbamazepine (CBZ) found in serum. The retention time of unconjugated 9-OH-CBZ should be known when using a chromatographic method, because it appears in concentrations varying from one eighth to one third of the CBZ-10,11-epoxide (CBZ-E) concentration and may therefore cause analytical interactions. Liquid chromatography/electrospray mass spectrometry ((LC/ES-MS) in a serum extract identified and confirmed 9-OH-CBZ.

Vigabatrin dosing during haemodialysis.

The antiepileptic drug vigabatrin has shown efficacy in the treatment of patients with refractory epilepsy. Unlike many other antiepileptics it is not bound to plasma protein and mainly eliminated by the kidney. Although the therapeutic and toxic serum concentration range is not clearly defined and efficacy and toxicity are not closely correlated with the dose, factors decreasing vigabatrin elimination such as advanced age or renal failure may pose risk of untoward effects.

Analyses of the pattern of therapeutic drug monitoring in a university hospital laboratory. Suitability and performance of the CEDIA assays.

New homogeneous enzyme immunoassays (CEDIA assays) for therapeutic drug monitoring were evaluated on Boehringer Mannheim/Hitachi 704. A fluorescence polarization immunoassay and HPLC were chosen as comparison methods. A good correlation of patient data was observed for both methods (slopes 1.