Neurological burden and outcomes of excessive β-lactam serum concentrations of critically ill septic patients: a prospective cohort study

BACKGROUND

Therapeutic drug monitoring (TDM) contributes to optimizing exposure to β-lactam antibiotics. However, how excessive exposure to β-lactams can increase the burden of care of critically ill patients is unclear.

PATIENTS AND METHODS

In a prospective cohort study, we examined whether excessive β-lactam serum concentrations contribute to neurological deterioration and the associated complications of adult septic patients without recent history of neurological disease treated with β-lactams in a medical ICU. Excessive β-lactam concentrations were defined as serum concentrations that exceeded the upper limit of the therapeutic range recommended by the French Societies of Pharmacology and Therapeutics (SFPT) and Anesthesia and Intensive Care Medicine (SFAR). Neurological deterioration was defined as an increase in the neurological Sequential Organ Failure Assessment score (nSOFA) of ≥1 between the day of starting treatment at admission and the day of TDM performed 2 days after treatment initiation.

RESULTS

We included 119 patients [median age: 65 years; males: 78 (65.5%)] admitted for acute respiratory distress [59 (49.6%)] or septic shock [25 (21%)]. In adjusted logistic regression analysis, an excessive β-lactam serum concentration was associated with neurological deterioration [OR (95% CI): 10.38 (3.23-33.35), P < 0.0001]. Furthermore, in adjusted linear regression analysis, an excessive β-lactam serum concentration was associated with longer time to discharge alive (β=0.346, P = 0.0007) and, among mechanically ventilated patients discharged alive, with longer time to extubation following the withdrawal of sedation (β=0.248, P = 0.0030).

CONCLUSIONS

These results suggest that excessive exposure to β-lactams could complicate the management of septic patients in the ICU and confirm the clinical relevance of the upper concentration limits recommended for dose reduction.

Abnormal laboratory findings and plasma concentration monitoring of lopinavir and ritonavir in COVID-19

It is not known whether the adverse events (AEs) associated with the administration of lopinavir and ritonavir (LPV/r) in the treatment of COVID-19 are concentration-dependent. In a retrospective study of 65 patients treated with LPV/r and therapeutic drug monitoring (TDM) for severe forms of COVID-19 (median age: 67; males: 41 [63.1%]), 33 (50.8%) displayed a grade ≥2 increase in plasma levels of hepatobiliary markers, lipase and/or triglycerides. A causal relationship between LPV/r and the AE was suspected in 9 of the 65 patients (13.8%). At 400 mg b.i.d., the plasma trough concentrations of LPV/r were high and showed marked interindividual variability (median [interquartile range]: 16,600 [11,430-20,842] ng/ml for lopinavir and 501 [247-891] ng/ml for ritonavir). The trough lopinavir concentration was negatively correlated with body mass index, while the trough ritonavir concentration was positively correlated with age and negatively correlated with prothrombin activity. However, the occurrence of abnormal laboratory values was not associated with higher trough plasma concentrations of LPV/r. Further studies will be needed to determine the value of TDM in LPV/r-treated patients with COVID-19.

Pitfalls of toxicological investigations in hair, bones, and nails in extensively decomposed bodies: illustration with two cases

It is difficult to carry out toxicological investigations in biological samples collected from extensively decomposed bodies and to interpret obtained results as several pitfalls should be considered: redistribution phenomena, degradation of xenobiotics during the postmortem period, contamination by putrefaction fluids, and external contamination. This work aims to present two cases in order to illustrate and discuss these difficulties in this tricky situation. Case#1: the body of a 30-year-old woman was found in a wooded area (1 month after she has been reported missing by her family): hair and a femur section were sampled. Case#2: the decomposed corpse of a 52-year-old man was found in a ditch: hair and nails were sampled. After decontamination steps, toxicological investigations were performed using liquid chromatography with high-resolution mass spectrometry and tandem mass spectrometry detection methods. In case#1, the same drugs or metabolites (benzodiazepines, propranolol, tramadol, acetaminophen, paroxetine, and oxetorone) were detected in hair and in bone specimens. This result combination strongly suggests intakes close to the time of death for three of them (oxazepam, lormetazepam, and propranolol). In case#2, results of toxicological investigations in hair and nails [(hair/nail concentration in ng/mg) nordiazepam (1.12/1.06), oxazepam (0.113/0.042), zolpidem (0.211/< 0.01), hydroxyzine (0.362/< 0.01), and cetirizine (0.872/1.110)] were both consistent with several drug intakes but were not contributory to cause of death determination. In case of positive toxicological results in biological samples collected from extensively decomposed bodies (such as hair, bones, or nails), it is challenging to determine the time, and even more, the level of the dose of exposure(s).

Effects of Smoking Exposure in Infants on Gastroesophageal Reflux as a Function of the Sleep-Wakefulness State

OBJECTIVE

To determine whether perinatal smoking exposure is associated with gastroesophageal reflux (GER)-related changes in sleep-wakefulness states in neonates.

STUDY DESIGN

Thirty-one neonates, referred for the investigation of suspected GER, were recruited and underwent multichannel impedance-pH monitoring and synchronized 8- to 12-hour polysomnography. The infants' exposure to tobacco smoke was estimated by means of a urine cotinine assay. The total number, frequency (h^-1), and mean duration (minutes) of GER-pH (reflux events detected by the pH electrode only) and GER-imp (reflux events with bolus movement detected by impedance) events were determined. Intergroup differences (smoking-exposed group vs nonexposed group) were probed with nonparametric, unpaired Mann-Whitney U tests. A χ² test was used to assess a possible intergroup difference in bolus retrograde migration during GER-imp events.

RESULTS

According to the urine cotinine assay, 21 of the 31 neonates had been exposed to cigarette smoke during the perinatal period. The number (and frequency) of GER-imp was significantly greater (P = .016) in the exposed group (29 [0-90]) than in the nonexposed group (12 [2-35]). Migration of the esophageal bolus from the distal segment to the most proximal segment was significantly more frequent (P = .016) in the exposed group (83% of GER) than in the nonexposed group (41%). The GER pattern associated with smoking exposure was particularly obvious during Rapid eye movement sleep.

CONCLUSIONS

The more frequent occurrence and greater proximal migration of GER-imp in the smoking-exposed group (especially during rapid eye movement sleep) may have clinical relevance. Smoking exposure is a preventable risk factor for limiting the occurrence of GER in neonates.

Efficacy and safety of nicotinamide in haemodialysis patients: the NICOREN study

Background

Nicotinamide (NAM) has been proposed as an alternative treatment to phosphate binders for hyperphosphataemia in chronic kidney disease.

Methods

The NICOREN multicentre, open-label and randomized study was designed to examine non-inferiority and safety of NAM when compared with sevelamer (SEV) in chronic haemodialysis patients. One hundred patients were randomized to either NAM or SEV treatment for 24 weeks. Serum biochemistry and NAM's main metabolite, N -methyl-2-pyridone-5-carboxamide (2PY), were measured to assess compliance, efficacy and safety.

Results

After 24 weeks, we observed a comparable decrease in serum phosphorus in the NAM and SEV treatment arms, from 2.1 ± 0.4 to 1.8 ± 0.5 and 2.3 ± 0.5 to 1.7 ± 0.5 mM (P = not significant), respectively. The criterion for non-inferiority was, however, not met due to a more limited number of patients being included than planned. Treatment discontinuation due to adverse events was 1.6 times higher in the NAM than in the SEV group with only 55% of study completers in the NAM arm versus 90% in the SEV arm. Thrombocytopenia was observed in four NAM-treated patients. Serum 2PY levels were comparable at baseline, but increased markedly in the NAM group, but not in the SEV group, at 24 weeks (P < 0.0001).

Conclusions

Thus, both drugs are equally effective in lowering serum phosphorus, but patients' tolerance of NAM was largely inferior to that of SEV. Extremely high 2PY levels may contribute to NAM's side effects.

[Drug use and driving]

Some drugs are known to impair driving because they can change the vision or hearing, and/or disrupt the intellectual or motor abilities: impaired vigilance, sedation, disinhibition effect, the coordination of movement disorders and the balance. The doctor during prescribing and the pharmacist during deliverance of drug treatment should inform their patients of the potential risks of drugs on driving or operating machinery. The driver has direct responsibility, who hired him and him alone, to follow the medical advice received. The pictograms on the outer packaging of medicinal products intended to classify substances according to their risk driving: The driver can whether to observe simple precautions (level one "be prudent"), or follow the advice of a health professional (level two "be very careful"), or if it is totally not drive (level three "danger caution: do not drive"). This classification only evaluates the intrinsic danger of drugs but not the individual variability. Medicines should be taken into account also the conditions for which the medication is prescribed. It is important to inform the patient on several points.

[Recommended dosage adaptation based on renal function is not always sufficient to avoid betalactam antibiotics side effects]

The potential neurotoxicity of betalactam antibiotics are well-known and is frequently associated with drug accumulation in patients with renal failure since these antibiotics are eliminated mostly by kidneys. The regional center of pharmacovigilance of Amiens has collected since 10 years, 20 notifications of neurotoxicity induced by betalactam antibiotics. The series included eight women and 12 men. Mean age was 65 years (26-84). The drug accumulation hypothesis was strengthened in nine cases by assays of plasma levels residual concentrations. In 17 cases, betalactam antibiotics dosage was adapted to creatinin clearance in accordance to the Summary of the Product Characteristics' (SPC) recommendations. For several drugs, no adaptation to renal function was proposed by SPC. Dosage adaptation based only on renal function as it's recommended is not always efficient to avoid neurological side effects.

A Novel LC-ESI-MS-MS Method for Sensitive Quantification of Colchicine in Human Plasma: Application to Two Case Reports

A novel method based upon liquid chromatography coupled to ion trap mass spectrometry (MS) detection with electrospray ionization interface has been developed for the identification and quantification of colchicine in plasma or whole blood. Colchicine was isolated from plasma using a liquid-liquid extraction with dichloromethane at pH 8.0 and embutramide as an internal standard, with satisfactory extraction recoveries. Solutes were separated on a 3-microm C18 Uptisphere (Interchim) column (150 x 2.0-mm i.d.) using acetonitrile/2 mM NH4COOH pH 3.8 buffer (50:50, v/v) as the mobile phase with a flow-rate of 200 microL/min. Data were collected either in full-scan MS mode at m/z 100-450 or in full-scan MS-MS mode, selecting the ion m/z 400.1 for colchicine and m/z 294.1 for embutramide. The most intense daughter ion of colchicine (m/z 358.1) and embutramide (m/z 207.9) were used for quantification. Retention times were 2.40 and 4.25 min for colchicine and embutramide, respectively. Calibration curves were linear in the 0.50-50 ng/mL range. The limits of detection and quantification were 0.05 ng/mL and 0.50 ng/mL, respectively. The intra- and interassay precisions were < 14%, and the intra- and interassay accuracies were in the 97-105.8% range at either 2 or 20 ng/mL. A fatal case of colchicine self-poisoning with a lethal blood concentration of 60 ng/mL and nonfatal case with a plasma sample collected very late (at least 36 h after the ingestion) are presented. The described method enables the unambiguous identification and quantification of colchicine with a very good sensitivity, using only 1 mL of sample.

[Partnership between academic research and industry to study a new anti-osteoporotic drug]

The activity of the osteoclast, the cell responsible for bone resorption, is subjected to different regulation factors. Amongst these, those issued from the matrix, particularly released minerals such as calcium, are determinants. We have shown that variations in calcium concentration in the medium regulates resorption activity and duration of the osteoclast lifespan. The development of a new therapeutic agent, strontium ranelate, has shown very interesting clinical effects reliant on the stimulation of bone formation activity by osteoblasts and modulation of bone resorption activity. From our knowledge regarding osteoclast physiology, in particular calcium signaling pathways, and the control of different osteoclast cellular models, a consequent collaboration was formed between our laboratory and Servier in order to elaborate on the effects of strontium ranelate on the osteoclast. In several years, this collaboration has been further enriched by other collaborators in order to better understand this mechanism. It has also been shown that strontium likely interacts with the calcium-sensing receptor and that the pathways of intracellular signaling pathways activated by calcium and strontium ranelate via this receptor are different. In fact, within the scope of this collaboration with Servier, exchanges with other academic laboratories were initiated and collaboration on numerous techniques became possible. Then, it has been possible to confirm the presence of the calcium-sensing receptor on the osteoclasts and to demonstrate its role in the molecular events associated with strontium ranelate's effects on the osteoclast.

Troubles extrapyramidaux sous véralipride (Agréal®), traitement symptomatique des bouffées de chaleur : à propos de 17 cas

PURPOSE

Extrapyramidal disorders associated with veralipride therapy are rarely reported and often due to a drug misuse.

METHODS

We evaluated cases of extrapyramidal disorders associated with veralipride. Cases were extracted from the regional pharmacovigilance centre of Amiens database. From January 1, 1995 to September 30, 2004, cases were selected on the basis of the occurrence of extrapyramidal disorders under veralipride therapy.

RESULTS

Seventeen cases of veralipride-induced extrapyramidal disorders were found. They consist of 16 menopausal women and one old man with LH-RH antagonist-induced hot flushes. Mean age was 61 years (48-73). Adverse effects were acute dyskinesia (n=2) or parkinsonian syndrome, which occurred after several months or years of treatment (n=15). Parkinsonism was associated with other extrapyramidal symptoms in 8 cases: tardive dyskinesia (n=6), postural tremor (n=3), myoclonia (n=1), and trunk dystonia (n=1). In all cases, outcome was favorable after drug discontinuation. In most cases the tablet-free interval was not respected: this may lead to prolonged striatal D2 receptors blockade. It must be added that the diagnosis was often delayed and patients were considered as suffering from idiopathic Parkinson's disease.

CONCLUSIONS

Prescribers should be aware that veralipride is a neuroleptic and could induce potentially severe extrapyramidal disorders. Increase veralipride prescription is expected due to the recent restriction of hormonal replacement therapy for menopause. The physicians should also use veralipride according to the Summary of the Product Characteristics.