Thomas A. Jennison

A single-step assay for lidocaine and its major metabolite, monoethylglycinexylidide, in plasma by gas-liquid chromatography and nitrogen phosphorus detection.

Summary: A single-step extraction method for the analysis of lidocaine and its primary metabolite, monoethylglycinexylidide (MEGX), is described. Alkalinized plasma or serum is extracted with ethyl acetate. Trimecaine is used as the internal standard. One microliter of the ethyl acetate extraction solvent is injected directly onto a Carbowax-KOH column fitted to a gas chromatograph equipped with a nitrogen-phosphorus detector. This procedure provides a rapid and reliable analysis for lidocaine and MEGX, requires only a single glass tube, and eliminates back-extractions and solvent evaporation.

Spurious phenobarbital levels by fluorescence polarization immunoassay using TDX analyzer in patients with renal disease

Results of phenobarbital analyses are presented for 14 patients with chronic renal failure, and compared using gas-liquid chromatography (GLC), enzyme immunoassay (EIA), and fluorescence polarization immunoassay (FPIA). Correlation of FPIA with GLC and EIA was poor.

An Evaluation of the EMIT®st Assay for the Detection of Tricyclic Antidepressant Drugs in Plasma or Serum

The EMIT st assay for tricyclic antidepressant drugs (TADs) was evaluated for use as a screening technique in the detection of these drugs in serum or plasma. The qualitative assay was found to be rapid, easy to perform, requires no sample or reagent preparations, and reliably detected the TADs in patient samples at concentrations greater than or equal to 200 ng/mL. The technique also detected seventeen of nineteen patient samples with TAD concentrations ranging from 150-199 ng/mL and ten of forty-three samples with concentrations less than 150 ng/mL. The EMIT st assay was found to be a reliable technique for detecting high concentrations of TADs and is well-suited for use in emergency drug screening situations.

An Evaluation of Common Methods for Acetaminophen Quantitation for Small Hospitals

Rapid, reliable serum acetaminophen quantitations assist in the diagnosis of the toxic patient and direct the clinician in the course of aggressive treatment. Reliable performance must be tempered with economic consideration, especially for small laboratories with infrequent testing. Two commonly available colorimetric techniques for acetaminophen (nitration and ferric reduction) are evaluated using both commercial and laboratory reagents. Enzyme immunoassay (EMIT) is also performed. Results are compared to an HPLC reference method.

LAAM Induction: Behavioral Correlates

There has been great interest for the past few years in the development of 1-alpha-acetylmethadol (LAAM) as an alternative maintenance treatment agent for heroin addicts. This methadone derivative is capable of suppressing abstinence for up to 72 hours and this clinical effect is related to its biotransformation and accummulation of active metabolites, in particular noracetylmethadol (N-LAAM) and dinoracetylmethadol (DN-LAAM). As part of a cooperative pharmacokinetic study of LAAM between us and the University of Utah, we attempted to make certain observations on the patients’ cognitive functions and other behavioral parameters after each dosing, both during initial administration and after repeated dosing for several weeks, to see if these observations correlated with the level of active metabolites. This report deals with the correlation between the plasma level of the major metabolite N-LAAM and clinical observations including the results of several specific psychometric tests. It was anticipated that the results of these tests may reflect impairment or the lack thereof, in everyday functioning such as driving, operating equipment, ability to concentrate, memory, etc.