Quantification of Methylphenidate, Dexamphetamine, and Atomoxetine in Human Serum and Oral Fluid by HPLC With Fluorescence Detection

BACKGROUND

For psychostimulants, a marked individual variability in the dose-response relationship and large differences in plasma concentrations after similar doses are known. Therefore, optimizing the efficacy of these drugs is at present the most promising way to exploit their full pharmacological potential. Moreover, it seems important to examine oral fluid as less invasive biological matrix for its benefit in therapeutic drug monitoring for patients with hyperkinetic disorder.

METHODS

A high-performance liquid chromatography method for quantification of methylphenidate (MPH), dexamphetamine (DXA), and atomoxetine in serum and oral fluid has been developed and validated. The analytical procedure involves liquid-liquid extraction, derivatization with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a label and chromatographic separation on a Phenomenex Gemini-NX C18 analytical column using gradient elution with water-acetonitrile. The derivatized analytes were detected at 330 nm (excitation wavelength) and 440 nm (emission wavelength). To examine the oral fluid/serum ratios, oral fluid samples were collected simultaneously to blood samples from patients with hyperkinetic disorder.

RESULTS

The method allows quantification of all analytes in serum and oral fluid within 16 minutes under the same or similar conditions. Oral fluid/serum ratios for MPH and DXA were highly variable and showed an accumulation of these drugs in oral fluid.

CONCLUSIONS

The developed method covers the determination of MPH, DXA, and atomoxetine concentrations in serum and oral fluid after the intake of therapeutic doses. Oral fluid samples are useful for the qualitative detection of MPH and DXA.

Hyperkinetische Störungen im Kindes- und Jugendalter

Fragestellung: Die vorliegende Auswertung untersucht Prävalenz, Medikation sowie Alters- und Geschlechterverteilung bei Patienten mit hyperkinetischen Störungen in den KinderAGATE Kliniken 2009–2012. Methodik: Zweimal im Jahr an den sog. «Stichtagen» wurden anonymisiert von jedem Patienten Alter, Geschlecht, Hauptdiagnose, Medikation und zugehörige Dosierung dokumentiert. Die so gewonnenen Daten stellen eine herausragende Grundlage für die Beobachtung der tatsächlichen Verhältnisse in der Kinder- und Jugendpsychiatrie dar. Ergebnisse: Die Patienten mit hyperkinetischen Störungen (25.5 % Pat) waren im Vergleich zum Gesamtkollektiv durchschnittlich zwei Jahre jünger und wurden statistisch signifikant häufiger mit Psychopharmaka behandelt. Obwohl männliche Patienten zahlenmäßig dominieren (84.3 % HPat; Durchschnittsalter 9.9 Jahre vs. 15.7 % HPat; 10.1 Jahre), wurde der gleiche Anteil an männlichen und weiblichen Patienten mit Psychostimulanzien behandelt (48.0 % vs. 52.2 %). Neben Methylphenidat, Amphetamin und Atomoxetin wurden häufig Verordnungen für die Antipsychotika Risperidon und Pipamperon sowie zunehmend auch für Quetiapin dokumentiert. Schlussfolgerungen: Methylphenidat bleibt Mittel der Wahl in der Pharmakotherapie von ADHS. Der Anteil der stationär behandelten Patienten, die mit Neuroleptika behandelt wurden, ist im Untersuchungszeitraum tendenziell, jedoch nicht statistisch signifikant, angestiegen. Aufgrund der Diskrepanz zwischen vorhandener Evidenz und Verschreibungspraxis besteht weiterhin großer Bedarf an neuen Studien zu den Langzeitwirkungen und -nebenwirkungen von Psychopharmaka bei Kindern und Jugendlichen.

Improving early detection of childhood depression in mental health care: the Children׳s Depression Screener (ChilD-S)

Diagnosing childhood depression can pose a challenge, even for mental health specialists. Screening tools can aid clinicians within the initial step of the diagnostic process. For the first time, the Children׳s Depression Screener (ChilD-S) is validated in a mental health setting as a novel field of application beyond the previously examined pediatric setting. Based on a structured interview, DSM-IV-TR diagnoses of depression were made for 79 psychiatric patients aged 9-12, serving as the gold standard for validation. For assessing criterion validity, receiver operating characteristic (ROC) curves were calculated. Point prevalence of major depression and dysthymia was 28%. Diagnostic accuracy in terms of the area under the ROC curve was high (0.97). At the optimal cut-off point ≥12 according to the Youden׳s index, sensitivity was 0.91 and specificity was 0.81. The findings suggest that the ChilD-S is not only a valid screening instrument for childhood depression in pediatric care but also in mental health settings. As a brief tool it can easily be implemented into daily clinical practice of mental health professionals facilitating the diagnostic process, especially in case of comorbid depression.