Effects of Oral Fluid Contamination on Two Oral Fluid Testing Systems.

Effects of Oral Fluid Contamination on Two Oral Fluid Testing Systems.

J Anal Toxicol. 2013 Mar 6;
Reichardt EM, Baldwin D, Osselton MD

Oral fluid is a popular matrix for drug testing; however, little has been published concerning the effect that food or beverages may exert on oral fluid screening tests. This study describes the effects of 19 different foods, beverages and vinegars on two test systems, the Concateno Certus and Orasure Intercept. Samples giving positive screening results were subjected to confirmatory analysis using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry. Results showed that intermittent presumptive positive results for amphetamine, methadone, opiates and cocaine could be detected following the consumption of coffee, Coke, fruit juice, oranges, spicy food and toothpaste using the Orasure system if specimens were not collected in accordance with the manufacturer’s recommended collection procedure.Following the consumption of vinegar, presumptive positives were observed using the Orasure system for up to 30 min post-exposure. No presumptive positives were observed using the Concateno system. It is a widely held view that foods and beverages disperse from the mouth within 10-15 min after their consumption, and hence are unlikely to affect oral fluid drug tests. This study shows that vinegar can affect immunoassay screening for an extended period following its consumption. HubMed – drug


False-Positive Buprenorphine by CEDIA in Patients Prescribed Amisulpride or Sulpiride.

J Anal Toxicol. 2013 Mar 6;
Birch MA, Couchman L, Pietromartire S, Karna T, Paton C, McAllister R, Marsh A, Flanagan RJ

Buprenorphine is a potent partial opioid agonist that is analyzed in urine to (i) monitor adherence to maintenance or detoxification therapy and (ii) detect illicit use. Buprenorphine analysis is commonly conducted on urine by immunoassay, but is subject to cross-reactivity from other drugs/drug metabolites, including morphine, codeine and dihydrocodeine. This study reports false-positive buprenorphine analysis [Thermo Fisher Scientific cloned enzyme donor immunoassay (CEDIA)] in patients who denied unauthorized buprenorphine use prior to sampling, but who had been prescribed amisulpride. In two cases, confirmatory analysis by liquid chromatography-tandem mass spectrometry was negative (<0.5 µg/L) for buprenorphine and metabolites and positive for amisulpride. Although the cross-reactivity of amisulpride and sulpiride in the CEDIA buprenorphine assay is low (estimated at 0.003 and 0.002%, respectively), it remains a significant consideration given the likely high concentrations of these compounds in urine relative to the low cutoff of the buprenorphine assay. Neither amisulpride nor sulpiride was listed as potential sources of interference on the CEDIA data sheet when this work was performed. These findings highlight the importance of confirming immunoassay-positive buprenorphine results using a more selective analytical technique. HubMed – drug


An update on the management of hay fever in adults.

Drug Ther Bull. 2013 Mar 7;

Allergic rhinitis is a common disorder occurring in about one in four people in Britain with a peak onset during adolescence.1-3 Although not necessarily a serious illness, it can adversely affect quality of life and disrupt normal activities, and is a risk factor for asthma.2,3 The symptoms of seasonal allergic rhinitis/rhino-conjunctivitis caused by an IgE-mediated type 1 hypersensitivity reaction to airborne allergens, particularly pollens, and which typically occur between spring and autumn are commonly referred to as hay fever.3 There are a number of management options available including drug therapy. Several drugs can be bought over the counter in the UK, and so people with allergic rhinitis may commonly present to the pharmacy or to general practice. The choice of treatment will be influenced by the spectrum, intensity and frequency of symptoms, and should take into account safety, efficacy, cost and patient preferences. Some of the treatments now available have been developed since our previous review was published and include the newer antihistamines, oral leukotriene receptor antagonists (LTRA),i and sublingual allergen desensitisation immunotherapy.4. HubMed – drug


Relationship between CES2 genetic variations and rifampicin metabolism.

J Antimicrob Chemother. 2013 Mar 6;
Song SH, Chang HE, Jun SH, Park KU, Lee JH, Lee EM, Song YH, Song J

OBJECTIVES: Rifampicin is known to be deacetylated in vivo, resulting in its metabolite 25-desacetyl rifampicin, but the enzyme metabolizing rifampicin and the association of this process with any genetic variation have not yet been elucidated. In this study, genetic variations of a surrogate enzyme, carboxylesterase 2 (CES2), and their association with the metabolism of this drug, were investigated. METHODS: Plasma concentrations of rifampicin and 25-desacetyl rifampicin were measured in 35 patients with tuberculosis receiving a first-line antituberculosis treatment. Direct PCR-based sequencing of the CES2 gene, covering all 12 exons, the 5′-untranslated region (UTR), the 3′-UTR and intronic and promoter regions, was performed. A dual luciferase reporter assay was carried out to assess whether variations in the promoter region affected the transcription of this gene. RESULTS: Ten variations were detected, of which two were in the candidate promoter region, five in introns and three in the 3′-UTR. One of the variations in the 3′-UTR was a novel variation. Genotypes at three closely linked variations (c.-2263A?>?G, c.269-965A?>?G and c.1612?+?136G?>?A) and c.1872*302_304delGAA were associated with significantly different plasma rifampicin concentrations. The mean plasma rifampicin concentration significantly increased with the number of risk alleles at the three closely linked variations, while the plasma concentration decreased along with an increase in the number of risk alleles at c.1872*302_304delGAA. When HepG2 cells were transfected with a luciferase reporter construct bearing the c.-2263G allele, luciferase activities were consistently decreased (by 5%-10%) compared with those harbouring the c.-2263A sequence. CONCLUSIONS: Variations in CES2, especially c.-2263A?>?G in the promoter region, may alter rifampicin metabolism by affecting expression of the gene. HubMed – drug