Successful use of sustained low efficiency dialysis in a case of severe phenobarbital poisoning

Toxicokinetic evaluation during intoxication of psychotropic drugs using brain microdialysis in mice

In the event of an overdose, the pharmacokinetics of the drug may be altered, resulting in an unexpectedly rapid increase in blood and tissue drug concentrations. Because central nervous system (CNS)-acting drugs are the major cause of hospitalization for overdose, brain concentrations, which are closely related to the development of acute psychotropic symptoms, would be important. However, due to the lack of an appropriate model for overdose, it is difficult to predict the CNS symptoms of patients with acute poisoning. To clarify the toxicokinetics during intoxication with CNS-acting drugs, we investigated the relationship between the dose and concentrations in the blood and brain in mice. Therapeutic or toxic doses of phenobarbital, flunitrazepam, imipramine, and amoxapine were administered intraperitoneally to mice. Serum and extracellular fluid of the brain were collected up to 24 hr after administration and analyzed using LC-MS/MS to determine the pharmacokinetic parameters in the serum and brain. A comparison of the four psychotropic drugs showed that the toxicokinetics of amoxapine in the blood and brain are clearly different from others, with the brain concentrations being specifically highly susceptible to increase during dose escalation. These results are consistent with the CNS-related symptoms observed in amoxapine overdose. Therefore, the methodology of the current study could be useful for predicting CNS toxicity during psychotropic drug poisoning.

Antiepileptic Drug Removal by Continuous Renal Replacement Therapy: A Review of the Literature

Continuous renal replacement therapy (CRRT) is used for managing acute kidney injury in critically ill patients. Removal of antiepileptic drugs (AEDs) by CRRT could be significant and may complicate patients' intensive care unit stay. The objective of the current review was to summarize the available evidence for AED removal by CRRT. An electronic literature search of PubMed (1946 to May 2016), Medline (1946 to May 2016), and Embase (1974 to May 2016) databases for studies discussing AED removal by CRRT was conducted. A total of 31 case reports discussing 32 patients were found. AEDs reported were levetiracetam (n = 3), valproic acid (n = 9), carbamazepine (n = 10), phenytoin (n = 3), phenobarbital (n = 4), lacosamide (n = 1), gabapentin (n = 1), and topiramate (n = 1). Two-thirds of the reports were about using CRRT in drug overdose and one-third was about AED removal by CRRT during therapy. Based on the current limited evidence and pharmacokinetic characteristics of AEDs, renally eliminated AEDs and/or AEDs with limited protein binding such as levetiracetam are more likely to be removed by CRRT than AEDs that are mainly metabolized and extensively protein bound such as carbamazepine. In conclusion, there is not enough evidence to provide robust dosing recommendations for AEDs in patients undergoing CRRT. Further studies are needed.