Serum levels of nimodipine in enteral and parenteral administration in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND: The aim of this study was to evaluate serum nimodipine concentrations in patients with aneurysmal subarachnoid hemorrhage (SAH) after parenteral therapy and a following course of enteral administration. METHODS: SAH patients were treated with intravenous nimodipine (2 mg/h) during the 1st week after hemorrhage, and on day 8, we switched over to enteral administration (60 mg/4 h), either orally or by gavage. Serum nimodipine concentrations were measured on days 3, 5, 8, 9 and 12. Area under the curve (AUC) was calculated during parenteral and enteral therapy. The data of 15 patients were analyzed retrospectively. RESULTS: In this study, 157 blood samples were obtained. In seven samples, during the administration by gavage to two patients with high-grade SAH, the serum nimodipine concentrations were negligible. The AUC values during parenteral administration (median 149.3 ng-h/ml) were significantly higher than during oral administration on days 9 (median 92.1 ng-h/ml) and 12 (median 44.1 ng-h/ml) in seven patients (p = 0.030 and p = 0.016, respectively). The AUC values during parenteral administration were significantly higher than during administration by gavage on day 9 in eight patients (median 87.9 and 34 ng-h/ml, respectively, p = 0.001). The AUC values during enteral administration were higher in patients who received nimodine orally than in those who received it by gavage (median 52.3 and 23.1 ng-h/ml, respectively, p = 0.006). CONCLUSIONS: Enteral administration of nimodipine showed lower bioavailability during the 2nd week after SAH compared to parenteral application during the 1st week. Negligible serum concentrations were even expected when nimodipine was given by gavage in patients with high-grade SAH, thus suggesting that parenteral administration may be the better route in these patients.

Therapeutic and toxic blood concentrations of nearly 1,000 drugs and other xenobiotics.

INTRODUCTION: In order to assess the significance of drug levels measured in intensive care medicine, clinical and forensic toxicology, as well as for therapeutic drug monitoring, it is essential that a comprehensive collection of data is readily available. Therefore, it makes sense to offer a carefully referenced compilation of therapeutic and toxic plasma concentration ranges, as well as half-lives, of a large number of drugs and other xenobiotics for quick and comprehensive information. METHODS: Data have been abstracted from original papers and text books, as well as from previous compilations, and have been completed with data collected in our own forensic and clinical toxicology laboratory. The data presented in the table and corresponding annotations have been developed over the past 20 years and longer. A previous compilation has been completely revised and updated. In addition, more than 170 substances, especially drugs that have been introduced to the market since 2003 as well as illegal drugs, which became known to cause intoxications, were added. All data were carefully referenced and more than 200 new references were included. Moreover, the annotations providing details were completely revised and more than 100 annotations were added. RESULTS: For nearly 1,000 drugs and other xenobiotics, therapeutic ("normal") and, if data were available, toxic and comatose-fatal blood-plasma concentrations and elimination half-lives were compiled in a table. CONCLUSIONS: In case of intoxications, the concentration of the ingested substances and/or metabolites in blood plasma better predicts the clinical severity of the case when compared to the assumed amount and time of ingestion. Comparing and contrasting the clinical case against the data provided, including the half-life, may support the decision for or against further intensive care. In addition, the data provided are useful for the therapeutic monitoring of pharmacotherapies, to facilitate the diagnostic assessment and monitoring of acute and chronic intoxications, and to support forensic and clinical expert opinions.

Fentanyl: toxic or therapeutic? Postmortem and antemortem blood concentrations after transdermal fentanyl application.

In forensic toxicology, several fatal intoxications with fentanyl have occurred in the recent past, but there are rare discussions in the literature of postmortem fentanyl blood concentrations subsequent to lethal and non lethal applications. To study this problem, we analyzed postmortem blood concentrations (vena femoralis) of 118 cases with therapeutic use of fentanyl and compared them with serum levels of 27 living persons after therapeutic administration of fentanyl patches (Durogesic). Basically, blood concentrations in postmortem specimens cannot be directly compared with in vivo serum levels: in our study, we observed that postmortem fentanyl blood concentrations were on average up to nine times higher than in vivo serum levels at the same dose. These differences could be explained by postmortem redistribution, but they were higher than expected on the basis of the physical and chemical properties of fentanyl alone. The special pharmacokinetics of the drug after long term transdermal application seem to play an important role in this phenomenon. In addition, there was no clear correlation between transdermal fentanyl dose and blood or serum concentrations, either antemortem or postmortem. Our study provides extensive data for postmortem peripheral blood concentrations after therapeutic non-fatal fentanyl patch application and demonstrates once more that in forensic toxicology, blood concentrations must be holistically interpreted with respect to all aspects of a case.

Myeloperoxidase deficiency preserves vasomotor function in humans.

AIMS: Observational studies have suggested a mechanistic link between the leucocyte-derived enzyme myeloperoxidase (MPO) and vasomotor function. Here, we tested whether MPO is systemically affecting vascular tone in humans. METHODS AND RESULTS: A total of 12 135 patients were screened for leucocyte peroxidase activity. We identified 15 individuals with low MPO expression and activity (MPO(low)), who were matched with 30 participants exhibiting normal MPO protein content and activity (control). Nicotine-dependent activation of leucocytes caused attenuation of endothelial nitric oxide (NO) bioavailability in the control group (P < 0.01), but not in MPO(low) individuals (P = 0.12); here the MPO burden of leucocytes correlated with the degree of vasomotor dysfunction (P = 0.008). To directly test the vasoactive properties of free circulating MPO, the enzyme was injected into the left atrium of anaesthetized, open-chest pigs. Myeloperoxidase plasma levels peaked within minutes and rapidly declined thereafter, reflecting vascular binding of MPO. Blood flow in the left anterior descending artery and the internal mammary artery (IMA) as well as myocardial perfusion decreased following MPO injection when compared with albumin-treated animals (P < 0.001). Isolated IMA-rings from animals subjected to MPO revealed markedly diminished relaxation in response to acetylcholine (P < 0.01) and nitroglycerine as opposed to controls (P < 0.001). CONCLUSION: Myeloperoxidase elicits profound effects on vascular tone of conductance and resistance vessels in vivo. These findings not only call for revisiting the biological functions of leucocytes as systemic and mobile effectors of vascular tone, but also identify MPO as a critical systemic regulator of vasomotion in humans and thus a potential therapeutic target.

Urinary ethyl glucuronide as a novel screening tool in patients pre- and post-liver transplantation improves detection of alcohol consumption.

UNLABELLED: Optimal selection of liver transplant candidates and early detection of alcohol relapse after orthotopic liver transplantation (OLT) is necessary to improve long-term outcomes. In this study, urinary ethyl glucuronide (uEtG) was prospectively evaluated as a novel screening tool for alcohol detection in the transplant setting. Overall, 141 liver transplant candidates and recipients, visiting the outpatient clinic for a total of 308 times, were included. At each visit, the alcohol markers, uEtG, ethanol, methanol, and carbohydrate-deficient transferrin (CDT), as well as the state markers, alanine transaminase, aspartate transaminase, gamma glutamyl transpeptidase (GGT), and mean corpuscular volume (MCV), were determined, then compared to patients' self-reports on alcohol intake. Urinary EtG significantly increased the detection rate of alcohol consumption, compared to the other alcohol markers (P < 0.001). In 93% of patients and at 92.5% of visits with positive alcohol markers, alcohol intake was detected by uEtG and/or CDT. Sensitivity and specificity of uEtG were 89.3% and 98.9% and of CDT were 25% and 98.6%, respectively. Urinary EtG was the best independent predictor of alcohol consumption in univariate and multivariate analysis (positive predictive value: 89.3%; negative predictive value: 98.9%; odds ratio: 761.1; P < 0.001). It showed a superior prediction rate, when compared to established alcohol and state markers, as well as to the combination of CDT with MCV and GGT, assessed by net reclassification improvement (NRI) (NRI: 1.01, P < 0.001; NRI: 1.755, P < 0.001). CONCLUSION: uEtG is a sensitive, specific, and reliable marker for the detection of recent alcohol intake pre- and post-OLT. In combination with CDT, uEtG should be considered as a tool for routine alcohol screening within the transplant setting.

The effect of opioid receptor blockade on the neural processing of thermal stimuli.

The endogenous opioid system represents one of the principal systems in the modulation of pain. This has been demonstrated in studies of placebo analgesia and stress-induced analgesia, where anti-nociceptive activity triggered by pain itself or by cognitive states is blocked by opioid antagonists. The aim of this study was to characterize the effect of opioid receptor blockade on the physiological processing of painful thermal stimulation in the absence of cognitive manipulation. We therefore measured BOLD (blood oxygen level dependent) signal responses and intensity ratings to non-painful and painful thermal stimuli in a double-blind, cross-over design using the opioid receptor antagonist naloxone. On the behavioral level, we observed an increase in intensity ratings under naloxone due mainly to a difference in the non-painful stimuli. On the neural level, painful thermal stimulation was associated with a negative BOLD signal within the pregenual anterior cingulate cortex, and this deactivation was abolished by naloxone.

Severe glycerol intoxication after Menière's disease diagnostic--case report and overview of kinetic data.

OBJECTIVE: Despite the fact that glycerol is well known as a nontoxic substance, intoxication with this tertiary alcohol is possible. We report on a 72-year-old male who was referred to the Department of Neurology with progressive neurological symptoms that had developed 4 h prior to admission. Temporally associated was the so-called glycerol test or Klockhoff test, which was performed for the diagnosis of suspected Menière's disease. The test procedure starts with oral administration of glycerol, the maximal dose should not exceed 1.5 g/kg of body weight. METHODS: Because of an apparently pathologically highly elevated serum concentration of triglycerides (3,465 mg/dL) measured 10 h after glycerol administration, the suspicion of an overdose of glycerol rose. During the following day, the glycerol serum concentration was analyzed at three different times. RESULTS: Based on these measurements, we determined pharmacokinetic parameters and estimated the initially ingested amount of glycerol of about 3.88-3.95 g/kg body weight. CONCLUSION: We conclude that an accidental overdose of glycerol must have occurred during the glycerol test to the patient.

Liquid ecstasy - a significant drug problem.

INTRODUCTION: Gamma-hydroxybutyric acid (GHB, "liquid ecstasy") and its legal pro-drugs gamma-butyrolactone and 1,4-butanediol are gaining in importance as recreational drugs in Germany. The effects of these substances are comparable with those of alcohol or benzodiazepines. Because of the wide availability of GHB physicians are increasingly being confronted with cases of intoxication. METHODS: This review is based on a selective literature search as well as on the authors' own experience and on information provided by the GIZ-Nord Poisons Centre, Göttingen, Germany. RESULTS: Consumption of a high dose of GHB or its prodrugs leads to severe intoxication with respiratory depression and coma. Only supportive therapy can be offered; no antidote is available. DISCUSSION: In any patient with impaired consciousness of unknown cause, the possibility of intoxication with GHB must be considered. Chemical detection of GHB in blood or urine is possible only using specific analytical methods and only within a short time frame (<12 h). Because of the short half-life of GHB, intoxications treated in intensive care units rarely show any complications. However, a number of fatalities have occurred. The potential abuse of GHB as a date rape drug must be borne in mind.

Case report: acute unintentional carbachol intoxication.

INTRODUCTION: Intoxications with carbachol, a muscarinic cholinergic receptor agonist are rare. We report an interesting case investigating a (near) fatal poisoning. METHODS: The son of an 84-year-old male discovered a newspaper report stating clinical success with plant extracts in Alzheimer's disease. The mode of action was said to be comparable to that of the synthetic compound 'carbamylcholin'; that is, carbachol. He bought 25 g of carbachol as pure substance in a pharmacy, and the father was administered 400 to 500 mg. Carbachol concentrations in serum and urine on day 1 and 2 of hospital admission were analysed by HPLC-mass spectrometry. RESULTS: Minutes after oral administration, the patient developed nausea, sweating and hypotension, and finally collapsed. Bradycardia, cholinergic symptoms and asystole occurred. Initial cardiopulmonary resuscitation and immediate treatment with adrenaline (epinephrine), atropine and furosemide was successful. On hospital admission, blood pressure of the intubated, bradyarrhythmic patient was 100/65 mmHg. Further signs were hyperhidrosis, hypersalivation, bronchorrhoea, and severe miosis; the electrocardiographic finding was atrio-ventricular dissociation. High doses of atropine (up to 50 mg per 24 hours), adrenaline and dopamine were necessary. The patient was extubated 1 week later. However, increased dyspnoea and bronchospasm necessitated reintubation. Respiratory insufficiency was further worsened by Proteus mirabilis infection and severe bronchoconstriction. One week later, the patient was again extubated and 3 days later was transferred to a peripheral ward. On the next day he died, probably as a result of heart failure. Serum samples from the first and second days contained 3.6 and 1.9 mg/l carbachol, respectively. The corresponding urine concentrations amounted to 374 and 554 mg/l. CONCLUSION: This case started with a media report in a popular newspaper, initiated by published, peer-reviewed research on herbals, and involved human failure in a case history, medical examination and clinical treatment. For the first time, an analytical method for the determination of carbachol in plasma and urine has been developed. The analysed carbachol concentration exceeded the supposed serum level resulting from a therapeutic dose by a factor of 130 to 260. Especially in old patients, intensivists should consider intoxications (with cholinergics) as a cause of acute cardiovascular failure.

[Investigations on the cause of death in a polytoxicomanic patient treated with wires and intermaxillary fixation for a chronic, infected mandibular fracture]. / Untersuchungen zur Todesursache bei einem polytoxikomanen Patienten mit dentoalveolären Schienenverbänden und intermaxillärer Fixation zur Versorgung einer chronisch infizierten Unterkieferfraktur.

The case of a 36-year-old male and former patient is presented who died for initially unknown reasons, with intermaxillary wire fixation for the treatment of an infected mandibular fracture still in place. The combined investigation of forensic experts and maxillofacial surgeons excluded aspiration and asphyxia as cause of death. Evidence was found for lethal methadone concentrations after intravenous drug abuse and a broncho pneumonia. Despite the clear evidence of a fatal intoxication in this case, caution must be exercised when dealing with individuals carrying intermaxillary fixation.

[Suicidal monointoxication with flunitrazepam. Further comment on coloration phenomena of the upper gastrointestinal tract]. / Suizidale Monointoxikation mit Flunitrazepam--ein Beitrag zu Färbungsphänomenen der Schleimhaut des oberen Gastrointestinaltrakts.

Fatal monointoxications with benzodiazepines, for instance with a suicidal intention, are exceptional findings. We report the autopsy case of an 82-year-old woman who died due to a suicidal monointoxication with Rohypnol 1 mg film tablets (therapeutical agent: flunitrazepam). 0.065 mg/L flunitrazepam and 0.34 mg/L 7-aminoflunitrazepam were detected in a postmortem heart blood sample and toxicological analysis revealed the metabolite 7-aminoflunitrazepam in gastric contents, too. At external examination, a bluish-turquoise coloration was seen around the woman's right nostril and within the oral cavity. At autopsy, similar coloration phenomena were seen on the mucosa of the distal esophagus and the stomach. Formerly, bluish stains on mouth and nostrils were considered indicative of intoxications with organophosphates such as parathion (E 605). More recently, case reports accumulate where an intoxication with Rohypnol 1 film tablets (containing the coloring agent indigocarmine in its core) have to be considered as a potential differential diagnosis of such coloration phenomena.