Baclofen Toxicity in a Patient with Hemodialysis-Dependent End-Stage Renal Disease.

BACKGROUND: Oral baclofen toxicity is extremely rare, but can affect patients with renal disease due to the drug's predominant renal clearance of approximately 69-85%. Patients with severely impaired renal function typically develop symptoms soon after initiating baclofen therapy, even at relatively low doses. CASE REPORT: A 69-year-old woman with a history of hemodialysis-dependent end-stage renal disease presented to the Emergency Department with encephalopathy, ataxia, and dystonia after the addition of a recent baclofen prescription for back pain (10 mg twice daily). She had been taking baclofen as prescribed for approximately 1 week when, the day prior to admission, she had increased her dose to a total of 40 mg. Diagnostic studies demonstrated the patient had chronic, end-stage renal disease and a supratherapeutic concentration of baclofen. Signs and symptoms resolved with hemodialysis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: It is of critical importance for emergency physicians to appreciate impaired baclofen clearance in those with underlying renal disease to obviate the potential for significant drug toxicity.

Rattlesnake venom-induced recurrent coagulopathy in first trimester pregnant women - Two Cases.

Delayed or recurrent coagulopathy can occur up to 14 days after North American rattlesnake envenomation in patients that have been treated with Crotalidae Polyvalent Immune Fab (CroFab). There is little data in the literature characterizing the sequelae of North American rattlesnake envenomation in pregnancy and no previously published reports of recurrent coagulopathy in pregnancy. CASE REPORT: We present 2 cases of first trimester pregnant women requiring readmission and retreatment with Crotalidae Polyvalent Immune Fab (CroFab) after developing recurrent/late coagulopathy following North American Rattlesnake Envenomation. Both patients were initially admitted and treated with CroFab following snakebite and discharged home without coagulopathy. One patient developed significant hypofibrinogenemia and subsequent hemorrhage after spontaneous abortion secondary to recurrent venom induced hypofibrinogenemia. DISCUSSION: Pregnant women with recurrent or late coagulopathy may be at higher risk for hemorrhage and spontaneous abortion and require more frequent laboratory monitoring after initial hospitalization and treatment with antivenom. A lower threshold for re-treatment with CroFab may be warranted in patients with fibrinogen less than 100mg/dL even in the setting of a normal platelet count.

Pancreatic Laceration in a Pediatric Patient: An Unexpected Diagnosis.

Pediatric pancreatic injuries are rare. We present an atypical case that occurred in a 4-year-old male. The child presented with a twenty-four-hour history of vomiting that had progressed to right lower quadrant abdominal pain on examination in the emergency department. The initial differential was gastroenteritis versus appendicitis. An abnormality on the ultrasonography and an elevated lipase level eventually led to an MRI showing a complete transection through the posterior margin of the pancreas. The patient was admitted to pediatric surgery and underwent a successful distal pancreatectomy with preservation of the spleen. On further inquiry specific to trauma, the child disclosed that his older brother had punched him in his abdomen the night before. The child's parents were separated due to intimate partner violence, and this older sibling recently had been very stressed. The sibling was referred for mental health evaluation and counseling, and the case reported to the county children and youth investigative services system. A low threshold for considering trauma and child abuse in the pediatric population is recommended when significant intra-abdominal injury is diagnosed.

Mechanistic Insights into the Hydrolysis of Organophosphorus Compounds by Paraoxonase-1: Exploring the Limits of Substrate Tolerance in a Promiscuous Enzyme.

We designed, synthesized and screened a library of analogs of the organophosphate pesticide metabolite paraoxon against a recombinant variant of human serum paraoxonase-1. Alterations of both the aryloxy leaving group and the retained alkyl chains of paraoxon analogs resulted in substantial changes to binding and hydrolysis, as measured directly by spectrophotometric methods or in competition experiments with paraoxon. Increases or decreases in the steric bulk of the retained groups generally reduced the rate of hydrolysis, while modifications of the leaving group modulated both binding and turnover. Studies on the hydrolysis of phosphoryl azide analogs as well as amino-modified paraoxon analogs, the former being developed as photo-affinity labels, found enhanced tolerance of structural modifications, when compared with O-alkyl substituted molecules. Results from computational modeling predict a predominant active site binding mode for these molecules which is consistent with several proposed catalytic mechanisms in the literature, and from which a molecular-level explanation of the experimental trends is attempted. Overall, the results of this study suggest that while paraoxonase-1 is a promiscuous enzyme, there are substantial constraints in the active site pocket, which may relate to both the leaving group and the retained portion of paraoxon analogs.