Neonatal Exposure to Tramadol through Mother's Breast Milk.

Tramadol is an opioid used in the treatment of moderate to moderately severe pain. Tramadol's use during pregnancy is generally avoided and may cause some reversible withdrawal effects in neonates, and its use during lactation is not licensed by the manufacturer. A small clinical trial reported infants were exposed to <3% of a mother's tramadol dose through breast milk with no evidence of harmful effects. Presented is a case study of breast milk, neonatal urine, and neonatal oral fluid for the analysis of tramadol and its metabolites, along with the validation of a method for the analysis of tramadol, O-desmethyltramadol, and N-desmethyltramadol in breast milk. Tramadol and its metabolites were extracted by solid-phase extraction after saponification of breast milk to remove lipids. Samples were analyzed by ultra-pressure liquid chromatography-tandem mass spectrometry. To the author's knowledge, this is the first report of tramadol and its metabolites in neonatal oral fluid. The breast milk concentrations were 63, 22, and 76 ng/mL for the analysis of tramadol, O-desmethyltramadol, and N-desmethyltramadol, respectively, on day of life 12. On day of life 20, the breast milk concentrations were 1,254, 388, and 937 ng/mL for the analysis of tramadol, O-desmethyltramadol, and N-desmethyltramadol, respectively. Oral fluid concentrations were 1,011, 1,499, and 406 ng/mL for the analysis of tramadol, O-desmethyltramadol, and N-desmethyltramadol, respectively, on day of life 20. Oral fluid concentrations were similar to breast milk for tramadol, almost four times higher for O-desmethyltramadol, and less than half for N-desmethyltramadol. The absolute infant dose was calculated to be 10 µg/kg/day and 294 µg/kg/day for tramadol on day of life 12 and 20, respectively.

A Case Study Evaluating the Efficacy of an Ad Hoc Hospital Collection Device for Fentanyl in Infant Oral Fluid.

Neonatal drug exposure is currently assessed using meconium, urine, blood, hair, or umbilical cord tissue/blood. Due to the invasiveness, challenges, and limitations of collection, and/or analytical difficulties of these matrices, oral fluid may be a more desirable matrix in diagnosing opioid exposure and risk for opioid withdrawal in neonatal abstinence syndrome. Traditional oral fluid collection devices are not viable options as they are too large for neonates' mouths and may contain chemicals on the collection pad. Unstimulated and stimulated infant oral fluid samples have been used for therapeutic drug monitoring as an alternative matrix to blood. The objective of this study was to assess the viability of a simple oral fluid collection system using a sterile foam-tipped swab rinsed in phosphate-buffered saline. Two infants were administered fentanyl for post-operative pain relief while hospitalized in the Neonatal Intensive Care Units at the Children's Hospital of Richmond of Virginia Commonwealth University. Oral fluid samples were collected at 16 h, 2 days, and/or 7 days following the start of intravenous infusion of fentanyl. Samples were analyzed by ultra-high-pressure liquid chromatography-tandem mass spectrometry for fentanyl and norfentanyl after solid-phase extraction. In one of the three samples tested, fentanyl and norfentanyl were detected at concentrations of 28 and 78 ng/mL, respectively. Based on the infusion rate, the theoretical oral fluid fentanyl concentration at steady state was calculated to be 33 ng/mL.

Formation of HETE-EAs and dihydroxy derivatives in mouse kidney tissue and analysis by high-performance liquid chromatography tandem mass spectrometry.

The kidneys play an important role in the long-term regulation of blood pressure by control of salt and water balance in the body through various systems including the endocannabinoid system. The endocannabinoid system consists of the two major cannabinoid receptor agonists, anandamide (AEA) and 2-arachidonylglycerol (2-AG), their hydrolyzing enzymes, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), and the cannabinoid receptors, CB1 and CB2. AEA can be converted into 12- and 15(S)-hydroperoxyeicosatetraenoic acid ethanolamides by 12-LOX and 15-LOX, respectively and can form epoxyeicosatrienoic acid- (EET-EAs) (5,6-, 8,9-, 11,12-, 14,15-) and hydroxyeicosatetraenoic acid- (HETE) ethanolamides. Furthermore, the EET-EAs produce a secondary metabolism by microsomal epoxide hydrolase to form the corresponding dihydroxyeicosatetraenoic acid-EAs (DiHETE-EA). Reference material was not available for DiHETE-EA. These metabolites were synthesized by incubation of the corresponding EET-EAs with mouse liver cytosol containing epoxide hydrolases. Presented is a solid phase extraction and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) for the extraction and quantitation of AEA, 2-AG, their metabolites, oleoylethanolamide (OEA), and palmitoylethanolamide (PEA), and the in vivo formation of the DiHETE-EAs in kidney after a single intravenous bolus administration of 20 mg/kg of anandamide in C57BL/6 J and FAAH KO mice.