GABA-receptor antagonists

Flumazenll [floo MAZ eh nill] is a GABA receptor antagonist that can rapidly reverse the effects of benzodiazepines. The drug is available by IV administration only. Onset is rapid but duration is short, with a half-life of about one hour. Frequent administration may be necessary to maintain reversal of a long-acting benzodiazepine. Administration of flumazenil may precipitate withdrawal in dependent patients or may cause seizures if a benzodiazepine is used to control seizure activity. Dizziness, nausea, vomiting, and agitation are the most common side effects. 

Phthalideisoquinolines a-narcotine and narcotoline (MD-IQ-C4L[Phe) (opium-derived spasmolytics) (+)-bicucculine (MD-IQ-C4L Phe-MD) (Corydalis species (Papaveraceae) GABA receptor antagonist). 

Wang PY, Slaughter MM (2005) Effects of GABA Receptor Antagonists on Retinal Glycine Receptors and on Homomeric Glycine Receptor Alpha Subunits. J Neurophysiol 93 3120... 

When Japanese star anise was mixed into a commercially sold herbal tea, perhaps inadvertently consumption of the tea was associated with adverse events in 63 Dutch consumers (1). Their symptoms occurred 2-4 hours after they drank the tea and included general malaise, nausea, and vomiting. In 22 cases hospitalization was required, and 16 had generalized tonic-clonic seizures. All made a full recovery after withdrawal of the herbal tea. Anisatin is a non-competitive GABA receptor antagonist, which causes nervous system hyperactivity, and the authors believed that this mechanism explained the high rate of seizures in these patients. 

CGP 35348 is a phosphinic acid derivative, a (GABAb) GABA receptor ANTAGONIST. It is used as a pharmacological tool, and shows ANTICONVULSANT / ANTIEPILEPTIC properties in animal models. 

GABAj receptors are of the seven-transmembrane G-protein-coupled type, and they have a widespread distribution in the body. Agonists at this receptor site include L-baclofen, CGP 27492 and CGP 35024. The receptors are negatively coupled to cAMP, and typical responses in neurons are to inhibit excitability by opening potassium channels or closing calcium channels. These inhibitory actions can be harnessed clinically for instance, baclofen is used as a muscle relaxant and has actions mainly at the spinal level within the GNS (see SKELETAL MUSCLE RELAXANTS). See GABA RECEPTOR ANTAGONISTS. 

TBPS (tert-butyl bicyclic thiophosphate) is a (GABAb) gaba receptor antagonist, used as a tool for studying binding sites of the mammalian CNS ( S labelled). It is a CNS stimulant and convulsant neurotoxin. 

Of the potent vertebrate GABA receptor antagonists bicuculline (20), pitrazepin (22), RU5135 (23) and... 

Bristow DR, Martin IL (1988) Light microscopic autoradiographic localization in rat brain of the binding sites for the GABA receptor antagonist [ H]SR95531 comparison with pHJGABA, distribution. Eur. J. Pharmacol, 148, 283-288. 

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