Analysis of cocaine, benzoylecgonine, ecgonine methyl ester, ethylcocaine and norcocaine in human urine using HPLC with post-column ion-pair extraction and fluorescence detection.

The measurement of cocaine and its major metabolites has been achieved by an HPLC method that compensates for their different solubilities and detection properties. Although ecgonine methyl ester is a major metabolite it is generally not measured by HPLC because it is poorly detectable by UV, and its water solubility makes recovery from urine difficult. Using modified solid-phase extraction procedures recoveries of 85% for ecgonine methyl ester, 97% for cocaine, 106% for benzoylecgonine and 80% for ethylcocaine have been obtained from urine. Increased chromatographic retention and detection sensitivity has been obtained by formation of the t-butyldimethylsilyl derivative of ecgonine methyl ester which was found to be stable in the HPLC mobile phase for at least 1 week. Alkylation of norcocaine and benzoylecgonine has improved their detection sensitivity and also chromatographic resolution. All calibrations were linear over the range 200-1000 ng ml-1 in urine with correlation coefficients > 0.99.     

Acetazolamide in hemodialysis patients: a rational use after ocular surgery.

Acetazolamide is a weak diuretic used to decrease production of aqueous humor in the eye. Hemodialysis patients undergoing ocular surgery may benefit from acetazolamide; however, no pharmacokinetic data are available for this group of patients. We report a patient who received acetazolamide 250 mg every 6 hours after ophthalmic surgery and developed reversible neurological side effects associated with very high plasma concentrations. Using pharmacokinetic analysis, we suggest an alternate administration of acetazolamide for end-stage renal patients.     

Community survey of primary dystonia in the city of Kolkata, India.

An epidemiological study on dystonia has not been reported from India. As part of a major study to find out the prevalence of major neurological disorders in the large urban city of Kolkata, Eastern India, we planned to determine the prevalence of primary dystonia. The study design was a cross-sectional study of a sample population obtained through stratified random selection and conducted in a two-stage procedure of screening by a nonprofessional team followed by confirmation of screened positive cases by the study neurologist. A total population of 52,377 was screened, and 29 subjects with dystonia were diagnosed. Out of them 23 subjects had primary dystonias [crude prevalence rate (CPR), 43.91/100,000; 95% confidence interval (CI), 28.41-64.81; age-standardized rates to world standard population, 49.06 (95% CI,31.74-72.41)] and all cases were focal type and predominantly of limb dystonia variety. Mean onset of dystonias were earlier in women (43.5 years) as compared to men (46.6 years). Thus our study on primary dystonia shows higher prevalence when compared with that of many studies globally, predominantly of focal type, earlier onset among women, and more cases of limb dystonias when compared with more prominent blepharospasm and cervical dystonias in western reports.