Drug Toxicities of Common Analgesic Medications in the Emergency Department

Tissue Perfusion and Diffusion and Cellular Respiration: Transport and Utilization of Oxygen

This article provides an overview of the journey of inspired oxygen after its uptake across the alveolar-capillary interface, and the interplay among tissue perfusion, diffusion, and cellular respiration in the transport and utilization of oxygen. The critical interactions between oxygen and its facilitative carriers (hemoglobin in red blood cells and myoglobin in muscle cells), and with other respiratory and vasoactive molecules (carbon dioxide, nitric oxide, and carbon monoxide), are emphasized to illustrate how this versatile system dynamically optimizes regional convective transport and diffusive gas exchange. The rates of reciprocal gas exchange in the lung and the periphery must be well-matched and sufficient for meeting the range of energy demands from rest to maximal stress but not excessive as to become toxic. The mobile red blood cells play a vital role in matching tissue perfusion and gas exchange by dynamically regulating the controlled uptake of oxygen and communicating regional metabolic signals across different organs. Intracellular oxygen diffusion and facilitation via myoglobin into the mitochondria, and utilization via electron transport chain and oxidative phosphorylation, are summarized. Physiological and pathophysiological adaptations are briefly described. Dysfunction of any component across this integrated system affects all other components and elicits corresponding structural and functional adaptation aimed at matching the capacities across the entire system and restoring equilibrium under normal and pathological conditions.

El Deib M. Protective Effect of Curcumin against Sodium Salicylate-Induced Oxidative Kidney Damage, Nuclear Factor-Kappa Dysregulation, and Apoptotic Consequences in Rats

This study examined the effect of sodium salicylates (SS), alone and in combination with curcumin (CUR), on kidney function and architecture in rats. Five rat groups were given 1 mL physiological saline/rat orally, 1 mL olive oil/rat orally, 50 mg CUR/kg bwt orally, 300 mg SS/kg bwt intraperitoneally, or CUR+SS for 15 days. The hematological indices, serum protein profile, serum electrolytes balance, oxidative stress, and lipid peroxidation of kidney tissues were assessed. The histopathological examination and immune expression of Caspase-3 and nuclear factor kappa (NF-κB) were conducted. The findings showed that SS injection induced nephrotoxic activity, including increased serum urea, creatinine, and uric acid levels. It also caused apparent pathological alterations with increased Caspase-3 and NF-κB immuno-expression. In addition, thrombocytopenia, leukocytosis, neutrophilia, hyponatremia, hypochloremia, hypocalcemia, and hypomagnesemia but not hyperkalemia and hyperphosphatemia were evident in SS-injected rats. Moreover, SS exposure increased serum α1 globulin, renal tissue malondialdehyde, and Caspase-3 levels but superoxide dismutase, glutathione peroxidase, and Bcl-2 levels declined. Meanwhile, CUR significantly counteracted the SS harmful impacts on kidneys but SS+CUR co-administration induced an anemic condition. Overall, CUR has an evident protective role against SS-induced renal damage, but the disturbed hematological alterations should be carefully taken into consideration in their combined use.

Rapid Preparation of a Large Sulfated Metabolite Library for Structure Validation in Human Samples

Metabolomics analysis of biological samples is widely applied in medical and natural sciences. Assigning the correct chemical structure in the metabolite identification process is required to draw the correct biological conclusions and still remains a major challenge in this research field. Several metabolite tandem mass spectrometry (MS/MS) fragmentation spectra libraries have been developed that are either based on computational methods or authentic libraries. These libraries are limited due to the high number of structurally diverse metabolites, low commercial availability of these compounds, and the increasing number of newly discovered metabolites. Phase II modification of xenobiotics is a compound class that is underrepresented in these databases despite their importance in diet, drug, or microbiome metabolism. The O-sulfated metabolites have been described as a signature for the co-metabolism of bacteria and their human host. Herein, we have developed a straightforward chemical synthesis method for rapid preparation of sulfated metabolite standards to obtain mass spectrometric fragmentation pattern and retention time information. We report the preparation of 38 O-sulfated alcohols and phenols for the determination of their MS/MS fragmentation pattern and chromatographic properties. Many of these metabolites are regioisomers that cannot be distinguished solely by their fragmentation pattern. We demonstrate that the versatility of this method is comparable to standard chemical synthesis. This comprehensive metabolite library can be applied for co-injection experiments to validate metabolites in different human sample types to explore microbiota-host co-metabolism, xenobiotic, and diet metabolism.

Toxic Ingestion of Acetaminophen and Acetylsalicylic Acid in a Parturient at 33 Weeks Gestation: A Case Report

The anesthetic management of toxic ingestion during pregnancy requires concomitant concerns for both mother and fetus. We describe the management of a parturient at 33 weeks of gestation after a suicide attempt by ingestion of acetaminophen (APAP) and acetylsalicylic acid (ASA). Timing of toxin ingestion must be determined, prompt antidote administration prioritized, and hepatotoxicity-induced hematologic impairment anticipated. Fetal exposure to toxins must also be minimized. The use of point-of-care rotational thromboelastometry in conjunction with standard coagulation testing in such cases facilitates consideration of neuraxial anesthesia and determination of risk for postpartum hemorrhage.

Delay-Dependent Impairments in Memory and Motor Functions After Acute Methadone Overdose in Rats

Methadone is used as a substitution drug for the treatment of opioid dependence and chronic pain. Despite its widespread use and availability, there is a serious concern with respect to the relative safety of methadone. The purpose of this study was to characterize how acute methadone overdose affects the cognitive and motor performance of naïve healthy rats. The methadone overdose was induced by administering an acute toxic dose of methadone (15 mg/kg; ip; the equivalent dose of 80% of LD50) to adolescent rats. Resuscitation using a ventilator pump along with a single dose of naloxone (2 mg/kg; ip) was administered following the occurrence of apnea. The animals which were successfully resuscitated divided randomly into three apnea groups that evaluated either on day 1, 5, or 10 post-resuscitation (M/N-Day 1, M/N-Day 5, and M/N-Day 10 groups) in the Y-maze and novel object memory recognition tasks as well as pole and rotarod tests. The data revealed that a single toxic dose of methadone had an adverse effect on spontaneous behavior. In addition, Recognition memory impairment was observed in the M/N-Day 1, 5, and 10 groups after methadone-induced apnea. Further, descending time in the M/N-Day 5 group increased significantly in comparison with its respective Saline control group. The overall results indicate that acute methadone-overdose-induced apnea produced delay-dependent cognitive and motor impairment. We suggest that methadone poisoning should be considered as a possible cause of delayed neurological disorders, which might be transient, in some types of memory or motor performance in naïve healthy rats.

Sex Differences in Poisonings Among Older Adults: An Analysis of the Toxicology Investigators Consortium (ToxIC) Registry, 2010 to 2016

PURPOSE

Adults aged >65 years are susceptible to intentional and unintentional poisoning, with contributing factors that include polypharmacy, comorbidity, susceptibility to medication error, and gaps in research. Although toxicologists are often tasked with managing and preventing poisoning among older adults, little is known about sex differences in these poisonings. The aim of this study was to review sex differences in poisonings among older adults managed at the bedside by medical toxicologists.

METHODS

All case subjects aged >65 years in the Toxicology Investigators Consortium (ToxIC) registry between January 2010 and December 2016 were reviewed. Data included reasons for exposure and consultation, exposure agents and routes, presenting clinical findings, and treatment provided. Cases missing age, sex, or primary reason for toxicology consultation data were excluded. We used χ² tests to assess differences in distribution of study variables according to participant sex.

FINDINGS

Among 51,441 total registry cases, 542 (1.05%) were excluded because of missing data. Among the remaining 50,899 cases, 2930 (5.8%) were included for age >65 years; 52.3% of older adults were female. Race was missing or unknown for 49.2% of cases. Adverse drug reactions were more commonly encountered in female subjects than in their male counterparts (9.6% vs 6.4%; P = 0.001). No statistically significant sex differences were observed for total numbers of intentional, unintentional pharmaceutical, and nonpharmaceutical exposures. The most common medications involved were cardiovascular (16.8%) and analgesics/opioids (14.8%). Female subjects were more likely than male subjects to be evaluated by a toxicologist for cardiovascular medications (18.7% vs 14.7%; P = 0.004) and analgesics/opioids (17.6% vs 11.8%; P < 0.001). Male subjects were more likely than female subjects to be evaluated for ethanol toxicity (7.4% vs 1%; P < 0.001) and for envenomations (4.2% vs 1.8%; P < 0.001). The most common route of exposure was oral ingestion (81.3%). Signs/symptoms were noted in 54.8% of cases, with the most common abnormal vital sign being bradycardia (17.2%). Pharmacologic support was the most common intervention and was more common in male subjects than in female subjects (17.7% vs 12.3%; P < 0.001). Deaths were reported in 38 female subjects (2.45%) and 46 male subjects (3.34%); there was no statistically significant difference in death rate according to sex (P = 0.148).

IMPLICATIONS

Older female adults were more commonly evaluated by a medical toxicologist for an adverse drug reaction than older male adults. Female patients were more likely than male patients to be evaluated for poisoning related to analgesic/opioids and cardiovascular medications, and older male patients more frequently received pharmacologic support than older female patients. No significant sex differences were observed in numbers of toxicology consultations for intentional, unintentional pharmaceutical, and nonpharmaceutical exposures.

Pain in the Elderly: Identification, Evaluation, and Management of Older Adults with Pain Complaints and Pain-related Symptoms

Pain is a common and often underappreciated and undermanaged problem in older adults. This article addresses the scope of the issue of pain prevalence in older adults, types of pain and their characteristics, approach to and clinical workup of older adults with pain complaints and pain-related symptoms, nonpharmacologic and pharmacologic management strategies, and caveats with attention to medication side effects in the elderly.

Spurious Hyperchloremia in the Presence of Elevated Plasma Salicylate: A Cohort Study

BACKGROUND

Acute metabolic acidosis is rarely associated with a reduced or negative anion gap (AG), but several case reports have described such an abnormality occurring in the setting of acute salicylate intoxication. The underlying cause of this phenomenon is unclear.

METHODS

In this retrospective cohort study, we reviewed our institutional database to identify all patients admitted for salicylate intoxication at Mayo Clinic (Rochester, MN, USA) from January 2010 through December 2012. Serum chloride was measured with the Cobas INTEGRA 400 plus electrode (expedited laboratory test) or Cobas 6000 (routine laboratory test). We compared blood chloride levels measured by the 2 devices in the presence of positive blood salicylate level.

RESULTS

Twelve adult patients with salicylate levels >20 mg/dL had markedly elevated chloride concentrations. The median (interquartile range) chloride level at admission was 120 (107-145) mmol/L on their initial laboratory studies, resulting in reduced or even negative AGs. None of the patients had bromide toxicity, nor did they have any other identifiable cause of hyperchloremia or decreased AG. Further testing of the same blood samples with an alternative measurement system (Roche Cobas 6000) yielded normal chloride values, indicating that falsely elevated chloride values with the initial testing led to the diminished or negative AG values.

CONCLUSION

Circulating levels of salicylate can interfere with chloride measured by using routine techniques, resulting in spurious hyperchloremia outcomes and erroneous AG values. In patients with acute metabolic acidosis and abnormally reduced or negative AG, salicylate interference with chloride measurement should be suspected.