Allopregnanolone and perampanel as adjuncts to midazolam for treating diisopropylfluorophosphate‐induced status epilepticus in rats. Issue 1 (11th September 2020)

• Record Type: Journal Article
• Authors: Dhir, Ashish; Bruun, Donald A.; Guignet, Michelle; Tsai, Yi‐Hua; González, Eduardo; Calsbeek, Jonas; Vu, Joan; Saito, Naomi; Tancredi, Daniel J.; Harvey, Danielle J.; Lein, Pamela J.; Rogawski, Michael A.
• Other Names: Laskin Jeffrey D. guestEditor.
• Is Part Of: Annals of the New York Academy of Sciences. Volume 1480:Issue 1(2020)
• Page Start: 183
• Page End: 206
• Publication Date: 2020-09-11
• Subjects: organophosphate nerve agent -- status epilepticus -- AMPA receptor antagonist -- GABAA receptor positive allosteric modulator -- neuroactive steroid -- benzodiazepine; Medical sciences -- Periodicals; Medicine -- Periodicals; Science -- Periodicals; 610
• DOI: 10.1111/nyas.14479
• Languages: English
• ISSNs: 0077-8923

Abstract

Abstract: Combinations of midazolam, allopregnanolone, and perampanel were assessed for antiseizure activity in a rat diisopropylfluorophosphate (DFP) status epilepticus model. Animals receiving DFP followed by atropine and pralidoxime exhibited continuous high‐amplitude rhythmical electroencephalography (EEG) spike activity and behavioral seizures for more than 5 hours. Treatments were administered intramuscularly 40 min after DFP. Seizures persisted following midazolam (1.8 mg/kg). The combination of midazolam with either allopregnanolone (6 mg/kg) or perampanel (2 mg/kg) terminated EEG and behavioral status epilepticus, but the onset of the perampanel effect was slow. The combination of midazolam, allopregnanolone, and perampanel caused rapid and complete suppression of EEG and behavioral seizures. In the absence of DFP, animals treated with the three‐drug combination were sedated but not anesthetized. Animals that received midazolam alone exhibited spontaneous recurrent EEG seizures, whereas those that received the three‐drug combination did not, demonstrating antiepileptogenic activity. All combination treatments reduced neurodegeneration as assessed with Fluoro‐Jade C staining to a greater extent than midazolam alone, and most reduced astrogliosis as assessed by GFAP immunoreactivity but had mixed effects on markers of microglial activation. We conclude that allopregnanolone, a positive modulator of the GABAA receptor, and perampanel, an AMPA receptor antagonist, are potential adjuncts to midazolam in the treatment of benzodiazepine‐refractory organophosphate nerve agent–induced status epilepticus. Abstract : In the present study, we demonstrate the potential of allopregnanolone, a positive modulator of the GABAA receptor, and perampanel, an AMPA receptor antagonist, as adjuncts to the benzodiazepine midazolam in the treatment of organophosphate nerve agent–induced status epilepticus using the rat diisopropylfluorophosphate model.