Modern Methods for Analysis of Antiepileptic Drugs in the Biological Fluids for Pharmacokinetics, Bioequivalence and Therapeutic Drug Monitoring

Epilepsy is a chronic disease occurring in approximately 1.0% of the world's population. About 30% of the epileptic patients treated with availably antiepileptic drugs (AEDs) continue to have seizures and are considered therapy-resistant or refractory patients. The ultimate goal for the use of AEDs is complete cessation of seizures without side effects. Because of a narrow therapeutic index of AEDs, a complete understanding of its clinical pharmacokinetics is essential for understanding of the pharmacodynamics of these drugs. These drug concentrations in biological fluids serve as surrogate markers and can be used to guide or target drug dosing. Because early studies demonstrated clinical and/or electroencephalographic correlations with serum concentrations of several AEDs, It has been almost 50 years since clinicians started using plasma concentrations of AEDs to optimize pharmacotherapy in patients with epilepsy. Therefore, validated analytical method for concentrations of AEDs in biological fluids is a necessity in order to explore pharmacokinetics, bioequivalence and TDM in various clinical situations. There are hundreds of published articles on the analysis of specific AEDs by a wide variety of analytical methods in biological samples have appears over the past decade. This review intends to provide an updated, concise overview on the modern method development for monitoring AEDs for pharmacokinetic studies, bioequivalence and therapeutic drug monitoring.

Measurement of Purine Contents in Korean Alcoholic Beverages / 대한류마티스학회지

OBJECTIVE: Gout is one of the most common forms of inflammatory arthritides among men, which is caused primarily by chronic hyperuricemia. Although pharmacological therapy is the mainstay treatment to manage gout, limiting the consumption of dietary purine is also important. Several epidemiological studies have reported that alcohol consumption is closely related to hyperuricemia and gout. The objective of this study was to determine the purine content in common Korean alcoholic beverages using high performance liquid chromatography (HPLC) to provide a dietary guideline for those with hyperuricemia or gout. METHODS: Thirty-five alcoholic beverages were analyzed. Blindly labeled samples of each alcoholic beverage were degassed and frozen. The sample preparation prior to HPLC followed the methods of Japanese researchers. HPLC was performed to analyze adenine, guanine, hypoxanthine, and xanthine content in the alcoholic beverages. RESULTS: The standard curves were linear for all purines. Purine contents were as follows: beer (42.26~146.39 micromol/L, n=12), medicinal wine (8.2 and 40.41 micromol/L, n=2), rice wine (13.19 micromol/L), Makgeolri (11.71 and 24.72 micromol/L, n=2), red wine (0, 6.03, and 17.9 micromol/L, n=3). No purines were found in fruit wine (n=2), Kaoliang (n=1), white wine (n=1), or distilled alcoholic beverages, such as soju (n=10) or whiskey (n=1). CONCLUSION: Among popular Korean alcoholic beverages, beer contained a considerable amount of purines, whereas distilled alcoholic beverages did not. Patients with either gout or hyperuricemia should avoid alcoholic beverages, especially those containing large amounts of purines.