title: Usefulness of saliva for measurement of 3,4-methylenedioxymethamphetamine and its metabolites: correlation with plasma drug concentrations and effect of salivary pH.
abstract: BACKGROUND
  Saliva is an alternative biologic matrix for drugs-of-abuse testing that offers the advantages of noninvasive, rapid, and easy sampling. We studied the excretion profile of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolites in both saliva and plasma, as well the effect of the drug on salivary pH.
  
  
  METHODS
  Saliva and plasma samples were obtained from eight healthy MDMA consumers after ingestion of a single 100-mg dose of the drug. Concentrations of MDMA and its main metabolites, 3,4-methylenedioxyamphetamine (MDA) and 4-hydroxy-3-methoxymethamphetamine (HMMA), in saliva and plasma were measured by gas chromatography-mass spectrometry. Apparent pharmacokinetic parameters for MDMA in saliva were estimated, and the saliva-to-plasma ratio at each time interval was calculated and correlated with salivary pH.
  
  
  RESULTS
  MDMA, MDA, and HMMA were detected in saliva. Salivary concentrations of MDMA were 1728.9-6510.6 microg/L and peaked at 1.5 h after drug intake. This was followed by a progressive decrease, with a mean concentration of 126.2 microg/L at 24 h. The saliva-to-plasma ratio was 32.3-1.2, with a peak of 18.1 at 1.5 h after drug administration. Salivary pH seemed to be affected by MDMA administration; pH values decreased by 0.6 units (mean pH values of 6.9 and 6.8 at 1.5 and 4 h after drug administration vs predose pH of 7.4).
  
  
  CONCLUSIONS
  Measurement of MDMA in saliva is a valuable alternative to determination of plasma drug concentrations in both clinical and toxicologic studies. On-site testing is also facilitated by noninvasive and rapid collection of salivary specimens.
authors.affiliation: Department of Pharmacology, Institut Municipal d'Investigació Mèedica (IMIM), E-08003 Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Navarro
authors.forename: S
authors.initials: S
authors.lastname: Pichini
authors.forename: M
authors.initials: M
authors.lastname: Farré
authors.forename: J
authors.initials: J
authors.lastname: Ortuño
authors.forename: P N
authors.initials: PN
authors.lastname: Roset
authors.forename: J
authors.initials: J
authors.lastname: Segura
authors.forename: R
authors.initials: R
authors.lastname: de la Torre
mesh_terms: D015104:3,4-Methylenedioxyamphetamine / Q000032:analysis / Q000097:blood; D000328:Adult; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000032:analysis / Q000097:blood; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D015813:Substance Abuse Detection / Q000379:methods*
chemical_list: D007773:Lactates; D015104:3,4-Methylenedioxyamphetamine; C005434:atrolactic acid; D018817:N-Methyl-3,4-methylenedioxyamphetamine