The anticholinergic toxidrome is well described and relatively common. Despite controversy, studies have shown that physostigmine is relatively safe and effective in reversing this toxidrome. We would expect toxicologists would be liberal in its use. We retrospectively analyzed data in the Toxicology Investigators Consortium (ToxIC) registry, representing data from medical toxicologists in multiple institutions nationwide, searching for patients who exhibited an anticholinergic toxidrome, determining what treatment(s) they received, and classifying the treatments as physostigmine, benzodiazepines, physostigmine and benzodiazepines, antipsychotics, or no definitive treatment. The causal agents of the toxidrome were as reported by the treating toxicologist. Eight hundred fifteen consecutive patients with anticholinergic toxidromes were analyzed. Benzodiazepines alone were given in 28.7 %, 12.4 % were given physostigmine alone, 8.8 % received both physostigmine and benzodiazepines, 2.7 % were given antipsychotics, and 47.4 % were given no definitive treatment. In patients who received only physostigmine, there was a significant difference in the rate of intubation (1.9 vs. 8.4 %, OR 0.21, 95 % CI 0.05-0.87) versus other treatment groups. Physostigmine was given at varying rates based on causative agent with use in agents with mixed or unknown effects (15.1 %) being significantly lower than those with primarily anticholinergic effects (26.6 %) (p<0.001). Patients with anticholinergic toxicity were more likely to receive benzodiazepines than physostigmine. Those patients who received only physostigmine had a significantly lower rate of intubation. Physostigmine was more likely to be used with agents exerting primarily anticholinergic toxicity than in those agents with multiple actions.
Dysrhythmias, although common in overdose situations, are not often seen after benzodiazepine exposures. We report two cases of transient atrioventricular block after benzodiazepine misuse. Case 1 is a 4-year-old boy who was found unresponsive after an ingestion of clonazepam. An electrocardiogram (EKG) performed on emergency department presentation demonstrated first-degree atrioventricular block (PR 206 ms). After flumazenil administration, he developed second-degree atrioventricular block (Mobitz Type 1). EKG abnormalities resolved by morning. Serum clonazepam was 478 ng/mL (laboratory clonazepam reference range, 10-75 ng/mL with a dose of up to 6 mg/day) 5 hours after being found unresponsive. Case 2 is a 23-year-old man who presented to the emergency department after ingesting risperidone, combination hydrocodone/acetaminophen, and alprazolam. On arrival, his EKG demonstrated sinus bradycardia with a PR interval of 182 msec. He subsequently developed second-degree atrioventricular block (Mobitz Type I). Sinus bradycardia with resolution of his atrioventricular block (PR 200 ms) was seen on a third EKG performed 5 hours after presentation. These two patients demonstrated transient first- and second-degree atrioventricular block after benzodiazepine exposure. Benzodiazepines have been shown to alter L-type Ca2+ channel function. This alteration in function may account for the dysrhythmias seen in our patients. Together, these cases serve to remind clinicians of this rare but potentially serious complication associated with benzodiazepine exposure.
Diphenhydramine toxicity manifests with signs of anticholinergic toxicity; therapy is generally supportive. In rare cases, patients can also present with a wide complex tachycardia due to sodium channel blockade. Treatment involves sodium bicarbonate. Lidocaine and hypertonic saline are used for arrhythmias refractory to sodium bicarbonate. Although intravenous fat emulsion (IFE) therapy is proposed as an adjunctive therapy due to the lipophilicity of diphenhydramine (octanol/water partition coefficient of 3.3), successful use of IFE after a confirmed sole ingestion of diphenhydramine is not previously reported. We present the case of a 30-year-old woman presenting with seizures, a wide complex tachycardia, and cardiovascular collapse after an ingestion of diphenhydramine refractory to other therapies with rapid improvement after IFE administration.
CONTEXT. Fentanyl patches are intended for transdermal use to treat pain. However, these patches have been abused by ingestion, offering a unique mode of drug delivery with unknown drug release characteristics. OBJECTIVES. In vitro fentanyl release from patches in simulated gastric and intestinal fluid was evaluated. MATERIALS AND METHODS. Ten 75 mcg/hr fentanyl transdermal patches (Mylan Pharmaceuticals Inc., Morgantown, WV), simulated gastric fluid without enzymes, and USP simulated intestinal fluid (Ricca Chemical Company, Arlington, TX) were obtained. Each fentanyl patch was placed into either 100 mL of simulated gastric fluid or 100 mL of simulated intestinal fluid. Flasks were agitated at 24 rpm while incubated at 36.8°C. Fluid was sampled at time zero and 5, 15, 30, 60, 120, and 180 min after submersion. Fentanyl was assayed using ultra performance liquid chromatography coupled with tandem mass spectrometry (AIT Laboratories, Indianapolis, IN). RESULTS. An average of 239 mcg and 1,962 mcg of fentanyl was released into gastric fluid and 338 mcg and 3,139 mcg into intestinal fluid in 5 min and 3 h, respectively. An average of 26% and 41% of 7.65 mg of fentanyl contained within the 75 mcg/hr patch was released into gastric and intestinal fluid in 3 h, respectively (p = 0.169, Student's t-test). DISCUSSION. Our results demonstrate fentanyl release within 5 min of submersion. CONCLUSION. These results help support the potential rapid onset of clinical compromise reported and are relevant to the design of future pharmacokinetic studies of fentanyl release from transdermal patches.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.