Biomedical subjects

S L Mikkelsen

Publications and source records attributed to S L Mikkelsen.

3 recordsLinked to original sources

PubMed1994

Does naloxone cause a positive urine opiate screen?

STUDY OBJECTIVE: To determine whether the excreted metabolites of naloxone hydrochloride cause positive urine toxicologic screens for opiates. DESIGN: Prospective, randomized, double-blinded human protocol. SETTING: Urban Level I military emergency department. PARTICIPANTS: Fourteen adult volunteers who took no routine medications, were not pregnant, had no known sensitivity to naloxone, and who were negative for a pretest urine and serum toxicologic screen. INTERVENTIONS: We administered either 2 or 4 mg IV naloxone to 14 subjects. Urine drug screening was obtained before administration and at 60 minutes, 6 hours, and 48 hours after administration. RESULTS: All urine drug screens using the enzyme-multiplied immunoassay technique were negative for opiates at both dosage levels. The sample size of 14 yielded a power of more than .99 to detect the difference between positive and negative samples. CONCLUSION: Although the metabolites of naloxone hydrochloride are similar in structure to oxymorphone and are excreted in human urine for several days, naloxone was not associated with a positive enzymatic urine screen for opiates.

Adult↗

PubMed1992

Effects of heat treatment on selected plasma therapeutic drug concentrations.

OBJECTIVE: We investigated the heat stability of six common therapeutic drugs routinely assayed in pharmacokinetic and clinical laboratories. DESIGN: Serum samples were spiked at three concentrations (subtherapeutic, therapeutic, and potentially toxic) with amikacin, gentamicin, tobramycin, phenytoin, theophylline, and phenobarbital. The samples were then heated at 56 degrees C and assayed by fluorescence polarization immunoassay at 15-minute intervals for one hour. SETTING: The study was conducted at a clinical research laboratory using standard laboratory methods. MAIN OUTCOME MEASURES: Drug concentrations of heated samples were compared with unheated controls using ANOVA to determine if degradation occurred over time with heating. RESULTS: Analysis of data revealed no degradation of any of the samples. CONCLUSIONS: Heat treatment of samples from high-risk individuals may be a mechanism to protect healthcare workers from exposure to the human immunodeficiency virus.

Drug Stability↗

PubMed1988

Adulterants causing false negatives in illicit drug testing.

Illicit-drug users may attempt to falsify results by in vitro adulteration of specimens. We investigated eight additives (NaCl, Visine, handsoap, Drano, bleach, vinegar, golden-seal tea, and lemon juice) claimed by drug users to invalidate enzyme immunoassay (EIA) drug assays. We also analyzed adulterated urine specimens to determine if they could be identified, adding adulterants at several concentrations to 222 EIA-positive specimens confirmed by gas chromatography and mass spectrometry (GC/MS) to contain illicit drugs. To identify adulterated urines, we monitored pH, relative density, and urine color and turbidity at adulterant concentrations that falsified EIA results. Specimens contaminated with NaCl had relative densities greater than 1.035. Liquid Drano, bleach, and vinegar shifted urine pH outside the physiological range. Golden-seal tea caused a dark appearance, and specimens containing liquid soap were unusually cloudy. Lemon juice had no effect on the assays. Visine was the only adulterant not detected. The adulterants interfered somewhat differently with each of the drug assays. EIA assays for illicit drugs can be invalidated by specimen adulteration producing false-negative results. Therefore, if urine drug testing is to be conducted, pH, relative density, and appearance should be assessed and suspect specimens should be rejected. Not all adulterants can be detected, so observed collection is strongly recommended.

Acetates↗