13-year-old girl with recurrent, episodic, persistent vomiting: out of the pot and into the fire.

Cyclic vomiting syndrome (CVS) is a well-established cause of recurrent vomiting in the pediatric population. Severe vomiting with chronic cannabis use, known as cannabinoid hyperemesis syndrome, has recently been more widely recognized as an etiology of persistent episodic vomiting. In turn, patients presenting with frequent episodes of CVS are now increasingly being screened for cannabinoid use. Because patients with persistent vomiting are also frequently prescribed a proton pump inhibitor (PPI) for their gastrointestinal symptoms, it is important to be aware of the potential for a PPI to cause an interaction that can lead to false-positive urine cannabinoid screening. We describe a case of a false-positive urine cannabinoid screen in a patient with CVS who received a dose of intravenous pantoprazole. The primary reference regarding drug screen interference from PPIs can be found in the pantoprazole package insert that refers to pre-Food and Drug Administration approval data. Although multiple sources on the Internet report the possibility of positive cannabinoid screens from pantoprazole, there are no known published reports of the phenomenon in the medical literature.

Urinary 5-hydroxyindoleacetic acid (5-HIAA) excretion during multiple-day high-dose chemotherapy.

Highly emetogenic drugs such as cisplatin induce an increase in the urinary 5-hydroxyindoleacetic acid (5-HIAA) level, the main metabolite of serotonin (5-HT), within the first 24 h following a single infusion, thus providing a possible cause for acute emesis and an explanation for the action of 5-HT3 antagonists. No further excretion peaks have been observed, suggesting that additional or serotonin-independent mechanisms cause delayed emesis. Our aim was to study the mechanisms behind emesis seen during a highly emetogenic chemotherapy regimen given as a continuous infusion over several days. Seven women treated with a 4-day high-dose chemotherapy (HDCT) regimen for breast cancer entered the study. Pooled urine samples were collected prior to and during chemotherapy for determining 5-HIAA excretion. An excretion peak in the urinary 5-HIAA level was observed within the first 24 h with no further peaks thereafter. Thus, the mechanisms behind the emesis experienced during this highly emetogenic multiple-day chemotherapy regimen from days 2-3 onwards would appear to be at least partially serotonin independent and would not be expected to be completely relieved by 5-HT3 antagonists alone.

Metabolic mimicry of Bartter's syndrome by covert vomiting: utility of urinary chloride determinations.

Bartter's syndrome characteristically exhibits the constellation of hypokalemic alkalosis with moderate kaliuresis, normotensive hyperreninemia, hyperaldosteronism, urinary hyperexcretion of prostaglandin E (PGE) and vascular hyporesponsivity to pressor agents. We describe precise biochemical mimicry of these metabolic abnormalities in a patient with surreptitious repetitive vomiting, in whom simple urinary chloride excretion data subsequently excluded the diagnosis of Bartter's syndrome.

The value of urinary chloride measurement in distinguishing surreptitious vomiting from Bartter's syndrome.

Urinary chloride measurement is a simple and common procedure but its value in clinical practice is not extensive. This case report highlights a practical and important use of this test. A patient presented with most of the clinical and metabolic derangements of Bartter's syndrome but was found to have extremely low or absent urinary chloride excretion. Her ability to excrete chloride was, however, intact during a chloride load test. The finding of low urinary chloride excretion did not support the diagnosis of Bartter's syndrome and suggested an extrarenal loss of chloride. This was confirmed when she eventually admitted to surreptitious vomiting.

Identification of ethylmalonic acid in urine of two patients with the vomitting sickness of Jamaica.

Large amounts of ethylmalonic acid have been identified in urines from two patients with the vomitting sickness of Jamaica. The amounts were 178 and 882 mug per mg creatinine which are 70 and 350 times, respectively, over control values. Other short and medium chain dicarboxylic acids including glutaric and adipic acids and those with eight and ten carbon chain, saturated and cis-unsaturated, were also detected in large quantities as in the case of hypoglycin treated rats; urine. However, the large increase of urinary ethylmalonic acid in these two human cases is in a sharp contrast to the findings in hypoglycin treated rats in which urinary ethylmalonic acid increased only 3 times over control. It appears that ethylmalonic acid is produced in the cases with the vomiting sickness of Jamaica by carboxylation of n-butyryl-CoA which is not oxidized further due to the inhibition by hypoglycin A. In case of hypoglycin-treated rats, n-butyryl-CoA is mainly conjugated with glycine or deacylated to free butyric acid.

3-Hydroxyisobutyric aciduria in two brothers.

Two Japanese brothers with 3-hydroxyisobutyric aciduria (3HiB-uria) are studied. The elder brother died of a ketoacidotic episode at the age of 4 years; the younger brother also manifested repeated episodes of ketoacidosis after 1 year of age. He is diagnosed as having 3HiB-uria by gas chromatography/mass spectometry analysis, using the unique fragment ions of 3HiB. Magnetic resonance imaging reveals focal white matter abnormalities. Protein restriction is effective for preventing the ketoacidotic episodes, although carnitine therapy seems less effective.

Bioanalytical investigation of asarone in connection with Acorus calamus oil intoxications.

Preparations of the plant Acorus calamus (calamus or sweet flag) (A. calamus) are available via internet trade and marketed as being hallucinogenic. In 2003-2006, the Swedish Poisons Information Centre received inquiries about 30 clinical cases of intentional intoxication with A. calamus products. The present investigation aimed to identify alpha- and beta-asarone, considered active components of A. calamus, and metabolites thereof in urine samples collected in seven of these cases. To further aid the identification of asarone biotransformation products, a calamus oil preparation was incubated with the fungus Cunninghamella elegans, which is used as a microbial model of mammalian drug metabolism. Using gas chromatography-mass spectrometry (GC-MS) analysis in selected ion monitoring mode, alpha-asarone was detected in five urine samples at concentrations ranging between approximately 11 and 1150 microg/L and beta-asarone in four of those at approximately 22-220 microg/L. A previously identified asarone metabolite, trans-2,4,5-trimethoxycinnamic acid (trans-TMC), was detected in the fungus broth by liquid chromatography-tandem mass spectrometry whereas cis-TMC was tentatively identified in the human urine samples. Using GC-MS, a hydroxylated asarone metabolite was identified both in fungus broth and urine samples. However, this study demonstrated no evidence for the presence of 2,4,5-trimethoxyamphetamine, claimed as a hallucinogenic component of A. calamus. The main clinical symptom reported by the patients was prolonged vomiting that sometimes lasted more than 15 h.

5-Hydroxyindoleacetic acid and substance P profiles in patients receiving emetogenic chemotherapy.

BACKGROUND: Even though direct cause and effect has not been proved, clinical evidence suggests serotonin and substance P (SP) are involved in the emetic response following chemotherapy. Because of several parallels, we hypothesized that SP release, like serotonin, may be propagated by chemotherapy and both substances can be measured in biological fluids, and correlated with a particular phase of emesis. METHODS: Urinary 5-hydroxyindoleacetic acid (5-HIAA) was assessed by HPLC; serum and urine SP were measured by immunoassay. In addition to construction of neurotransmitter profiles, all SP data were grouped according to cisplatin dosages, = or >75 mg/m(2) versus <75 mg/m(2), and phase of emesis, acute versus delayed. Analyses of these data were performed by repeated measures analysis of variance. RESULTS: Samples were collected over a 72-hour period from 26 adult patients who received cisplatin- (n = 13) or non-cisplatin-containing (n = 13) chemotherapy. Mean baseline 5-HIAA: creatinine ratios were 5.23 and 5.16 in females and males, respectively; mean baseline SP levels were 392 and 181 pg/mL in females and males, respectively. Comparisons between SP data stratified by cisplatin dosage and emetic phase were significantly different, P < 0.0001. CONCLUSIONS: Laboratory studies provide additional evidence that serotonin and SP are involved primarily, though not exclusively, in acute and delayed vomiting, respectively.

Urinary serotonin metabolite excretion during cisplatin chemotherapy.

BACKGROUND: Nausea and vomiting associated with cisplatin chemotherapy is a source of major morbidity that remains difficult to control. Acute phase (0-24 hours after induction of chemotherapy) nausea and vomiting parallels plasma serotonin release, which explains the effectiveness of 5HT3 antagonists; serotonin release in the delayed phase (24-48 hours after induction), during which consistent antiemetic control remains elusive, has not been investigated. The effect of propofol, a recent addition to the antiemetic armamentarium, on this serotonin release has not been studied. METHODS: Ten women with nausea and vomiting refractory to ondansetron and dexamethasone prophylaxis in their first cisplatin chemotherapy cycle were studied. Serial urinary 5-hydroxyindoleacetic acid (5-HIAA) levels were determined during a 48-hour period in 30 subsequent cycles, conducted under ondansetron/dexamethasone prophylaxis together with a propofol infusion. RESULTS: There was a significant urinary 5-HIAA peak 6 hours after induction of chemotherapy, with no peaks thereafter. Propofol did not inhibit serotonin release. CONCLUSIONS: Cisplatin chemotherapy is associated with serotonin release in the acute phase. There is no serotonin release during the delayed phase. Thus the use of 5HT3 antagonists for delayed-phase nausea and vomiting would appear questionable.

5-Hydroxyindoleacetic acid (5-HIAA) and cortisol excretion as predictors of chemotherapy-induced emesis.

This study evaluated the relationship between prechemotherapy cortisol and 5-hydroxyindoleacetic acid (5-HIAA) excretion and chemotherapy-induced emesis. The urinary excretion of cortisol and the serotonin metabolite 5-HIAA in the night before chemotherapy administration were measured in 28 and 49 female patients receiving > 300 mg m-2 carboplatin. Vomiting and nausea were documented over a 3 day observation period. Lower basal cortisol excretion was significantly correlated with vomiting with or without nausea occurring within the observation period. 5-HIAA showed only a weak correlation with emesis on days 1-3, but low 5-HIAA excretion was correlated with a higher proportion of patients vomiting on days 2-3 following chemotherapy. Low basal cortisol excretion might be useful as a predictor for chemotherapy-induced emesis and therefore should be evaluated prospectively in future studies.

Impaired water diuresis in a patient with pseudo-Bartter syndrome.

A 32-year-old man was diagnosed as having pseudo-Bartter syndrome due to surreptitious habitual vomiting and to maldigestion related to decayed teeth. His chief complaints were muscle pain and weakness. In this case, metabolic alkalosis, hypokalemia, hypochloremia, increased plasma renin activity and aldosterone levels were noticed with marked decreases in urinary chloride excretion. Creatinine clearance (GFR) and renal plasma flow (RPF) were also decreased. Blood pressure was normal, but the pressor response to angiotensin II was attenuated. Before treatment with 0.9% saline infusion, plasma vasopressin (AVP) was not suppressed sufficiently by lowering the plasma osmolality (Posm) with an oral water load (WL), but it normally responded to a rise in Posm due to hypertonic saline infusion. Moreover, plasma AVP was normally suppressed by WL after the replenishment of saline. Plasma atrial natriuretic peptide (ANP) was low before WL, but increased normally in response to WL. However, inconsistent with the normal response in this case, decreases in plasma AVP failed to dilute urinary osmolality and to increase urine flow, irrespective of the levels of plasma ANP. These results indicate that chronic inanition due to surreptitious vomiting causes impaired renal diluting ability through decreases in GFR and RPF, irrespective of the levels of plasma AVP and ANP.