Serial serum drug concentrations and prolonged anticholinergic toxicity after benztropine (Cogentin) overdose

Targeting the FKBP51/GR/Hsp90 Complex to Identify Functionally Relevant Treatments for Depression and PTSD

Genetic and epigenetic alterations in FK506-binding protein 5 ( FKBP5) have been associated with increased risk for psychiatric disorders, including post-traumatic stress disorder (PTSD). Some of these common variants can increase the expression of FKBP5, the gene that encodes FKBP51. Excess FKBP51 promotes hypothalamic-pituitary-adrenal (HPA) axis dysregulation through altered glucocorticoid receptor (GR) signaling. Thus, we hypothesized that GR activity could be restored by perturbing FKBP51. Here, we screened 1280 pharmacologically active compounds and identified three compounds that rescued FKBP51-mediated suppression of GR activity without directly activating GR. One of the three compounds, benztropine mesylate, disrupted the association of FKBP51 with the GR/Hsp90 complex in vitro. Moreover, we show that removal of FKBP51 from this complex by benztropine restored GR localization in ex vivo brain slices and primary neurons from mice. In conclusion, we have identified a novel disruptor of the FKBP51/GR/Hsp90 complex. Targeting this complex may be a viable approach to developing treatments for disorders related to aberrant FKBP51 expression.

Multi-organ dysfunction due to bath salts: are we aware of this entity?

Methylenedioxypyrovalerone (MDPV) is a synthetic, cathinone-derivative, central nervous system stimulant taken to produce a cocaine- or methamphetamine-like high. Physical manifestations include tachycardia, hypertension, arrhythmias, hyperthermia, sweating, rhabdomyolysis, hyperkalaemia, disseminated intravascular coagulation, oliguria and seizures. We report a patient who presented with severe metabolic acidosis, multi-organ dysfunction, rhabdomyolysis, hyperkalaemia and seizures. This case highlights that even though a urine drug screen for routine psychostimulant drugs is negative, clinicians need to be vigilant about the adverse effects of MDPV as a possible cause of multi-organ dysfunction. Substances such as this can only be detected by special tests, such as gas/liquid chromatography mass spectrometry. This is the first reported case of MDPV toxicity successfully treated in Australia to the best of our knowledge.

Prolonged Antimuscarinic Delirium in a Child Due to Benztropine Exposure Treated With Multiple Doses of Physostigmine

An 11-year-old boy presented with an antimuscarinic toxidrome due to benztropine and risperidone ingestion. His delirium was prolonged and difficult to treat with benzodiazepines. Multiple doses of physostigmine successfully treated it. Benztropine is a potent antimuscarinic agent, whereas risperidone has not been reported to cause antimuscarinic toxicity. The use of physostigmine to treat benztropine intoxication in a pediatric patient has not previously been described. In this case, multiple doses were used and were well tolerated.

Bath salts: a newly recognized cause of acute kidney injury

Bath salts are substance of abuse that are becoming more common and are difficult to recognize due to negative toxicology screening. Acute kidney injury due to bath salt use has not previously been described. We present the case of a previously healthy male who developed acute kidney injury and dialysis dependence after bath salt ingestion and insufflation. This was self-reported with negative toxicology screening. Clinical course was marked by severe hyperthermia, hyperkalemia, rhabdomyolysis, disseminated intravascular coagulation, oliguria, and sepsis. We discuss signs and symptoms, differential diagnoses, potential mechanisms of injury, management, and review of the literature related to bath salt toxicity.

Paralytic ileus requiring hospitalization secondary to high-dose antipsychotic polypharmacy and benztropine

Ileus can result from the combined activity of antipsychotic and anticholinergic medications. Despite frequent use, case reports in the literature are sparse. We present a patient who developed a paralytic ileus requiring extended hospitalization. Providers should minimize antipsychotic and concurrent anticholinergic medications, consider prophylactic bowel regimens and monitor for constipation.

Treatment of anticholinergic-induced ileus with neostigmine

A 33-year-old man with a history of recreational benztropine abuse presented to the emergency department with confusion, abdominal pain, and distention. An abdominal radiograph revealed gross fecal loading. He was initially treated with intravenous fluids and opiate analgesia. Subsequently, a diagnosis of anticholinergic poisoning was made, based on tachycardia, delirium, dry mucosa, and reduced bowel sounds. Treatment with tacrine reversed the delirium, and a history of repeated benztropine use was obtained. Persistent ileus was treated with repeated doses of neostigmine, and gastrointestinal motility returned with prompt defecation. Neostigmine appears to be useful in reversing ileus caused by anticholinergic drug overdose. Theoretically, it may be useful in reversing anticholinergic ileus resulting from acute drug overdose, allowing or enhancing decontamination, but the safety and potential efficacy of neostigmine in this scenario have not been established.