Replacement of Promethazine With Ondansetron for Treatment of Opioid- and Trauma-Related Nausea and Vomiting in Tactical Combat Casualty Care.

The current Tactical Combat Casualty Care (TCCC) Guidelines recommend parenteral promethazine as the single agent for the treatment of opioid-induced nausea and/or vomiting and give a secondary indication of "synergistic analgesic effect." Promethazine, however, has a well-documented history of undesired side effects relating to impairment and dysregulation of the central and autonomic nervous systems, such as sedation, extrapyramidal symptoms, dystonia, impairment of psychomotor function, neuroleptic malignant syndrome, and hypotension. These may be particularly worrisome in the combat casualty. Additionally, since 16 September 2009, there has been a US Food and Drug Administration (FDA) black box warning for the injectable form of promethazine, due to "the risk of serious tissue injury when this drug is administered incorrectly." Conversely, ondansetron, which is now available in generic form, has a well-established favorable safety profile and demonstrated efficacy in undifferentiated nausea and vomiting in the emergency department and prehospital settings. It has none of the central and autonomic nervous system side effects noted with promethazine and carries no FDA black box warning. Ondansetron is available in parenteral form and an orally disintegrating tablet, providing multiple safe and effective routes of administration. Despite the fact that it is an off-label use, ondansetron is being increasingly given for acute, undifferentiated nausea and vomiting and is presently being used in the field on combat casualties by some US and Allied Forces. Considering the risks involved with promethazine use, and the efficacy and safety of ondansetron and ondansetron?s availability in a generic form, we recommend removing promethazine from the TCCC Guidelines and replacing it with ondansetron.

Performance of a multi-disciplinary emergency department observation protocol for acetaminophen overdose.

The availability of 20-h N-acetylcysteine (NAC) infusion for low-risk acetaminophen (APAP) overdose enabled our center to implement an Emergency Department observation unit (OU) protocol as an alternative to hospitalization. Our objective was to evaluate our early experience with this protocol. This retrospective cohort study included all patients treated for low-risk APAP overdose in our academic hospital between 2006 and 2011. Cases were identified using OU and pharmacy records. Successful OU discharge was defined as disposition with no inpatient admission. Differences in medians with 95 % confidence intervals were used for comparisons. One hundred ninety-six patients received NAC for APAP overdose with a mean age of 35 years (SD 14); 73 % were white, and 43 % were male. Twenty (10 %) received care in the OU; 3/20(15 %) met criteria for inclusion in the OU protocol and 13/20(65 %) were discharged successfully. Out of the 196 patients, 10 met criteria for inclusion in the OU protocol but instead received care in the inpatient setting. The median total length of stay from presentation to ED discharge was 41 h for all patients treated in the OU, compared to 68 h for ten patients who met criteria for inclusion in the OU protocol but who were admitted (difference 27 h, 95 % CI 18-72 h). ED observation for APAP overdose can be a viable alternative to inpatient admission. Most patients were successfully discharged from the OU. This evaluation identified both over- and under-utilization of the OU. OU treatment resulted in shorter median length of stay than inpatient admission.

Chemical and radiological toxicity of depleted uranium.

A by-product of the uranium enrichment process, depleted uranium (DU) contains approximately 40% of the radioactivity of natural uranium yet retains all of its chemical properties. After its use in the 1991 Gulf War, public concern increased regarding its potential radiotoxicant properties. Whereas in vitro and rodent data have suggested the potential for uranium-induced carcinogenesis, human cohort studies assessing the health effects of natural and DU have failed to validate these findings. Heavy-metal nephrotoxicity has not been noted in either animal studies or Gulf War veteran cohort studies despite markedly elevated urinary uranium excretion. No significant residual environmental contamination has been found in geographical areas exposed to DU. As such, although continued surveillance of exposed cohorts and environments (particularly water sources) are recommended, current data would support the position that DU poses neither a radiological nor chemical threat.

Mitigation of pennyroyal oil hepatotoxicity in the mouse.

OBJECTIVES: Pennyroyal oil ingestion has been associated with severe hepatotoxicity and death. The primary constituent, R-(+)-pulegone, is metabolized via hepatic cytochrome P450 to toxic intermediates. The purpose of this study was to assess the ability of the specific cytochrome P450 inhibitors disulfiram and cimetidine to mitigate hepatotoxicity in mice exposed to toxic levels of R-(+)-pulegone. METHODS: 20-g female BALB/c mice were pretreated with either 150 mg/kg of cimetidine intraperitoneal (IP), 100 mg/kg of disulfiram IP, or both. After one hour, mice were administered 300 mg/kg of pulegone IP and were killed 24 hours later. Data were analyzed using ANOVA. Post-hoc t-tests used Bonferroni correction. RESULTS: There was a tendency for lower serum glutamate pyruvate transaminase in the disulfiram and cimetidine groups compared with the R-(+)-pulegone group. The differences were significant for both the cimetidine and the combined disulfram and cimetidine groups compared with the R-(+)-pulegone group. Pretreatment with the combination of disulfiram and cimetidine most effectively mitigated R-(+)-pulegone-induced hepatotoxicity. CONCLUSIONS: Within the limitations of a pretreatment animal model, the combination of cimetidine and disulfiram significantly mitigates the effects of pennyroyal toxicity and does so more effectively than either agent alone. These data suggest that R-(+)-pulegone metabolism through CYP1A2 appears to be more important in the development of a hepatotoxic metabolite than does metabolism via CYP2E1.