2840 Metharbital Metharbital is only found in individuals that have used or taken this drug. It was patented in 1905 by Emil Fischer working for Merck. It was marketed as Gemonil by Abbott Laboratories. It is a barbiturate anticonvulsant, used in the treatment of epilepsy. It has similar properties to phenobarbital. Metharbital binds at a distinct binding site associated with a Cl^- ionopore at the GABA_A receptor, increasing the duration of time for which the Cl^- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. All of these effects are associated with marked decreases in GABA-sensitive neuronal calcium conductance (gCa). The net result of barbiturate action is acute potentiation of inhibitory GABAergic tone. Barbiturates also act through potent (if less well characterized) and direct inhibition of excitatory AMPA-type glutamate receptors, resulting in a profound suppression of glutamatergic neurotransmission. 50-11-3 4099 C9H14N2O3 198.100440 White powder. 150.5°C 1980 mg/L (at 25°C) Metharbital binds at a distinct binding site associated with a Cl^- ionopore at the GABA_A receptor, increasing the duration of time for which the Cl^- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. All of these effects are associated with marked decreases in GABA-sensitive neuronal calcium conductance (gCa). The net result of barbiturate action is acute potentiation of inhibitory GABAergic tone. Barbiturates also act through potent (if less well characterized) and direct inhibition of excitatory AMPA-type glutamate receptors, resulting in a profound suppression of glutamatergic neurotransmission. No indication of carcinogenicity to humans (not listed by IARC). Metharbital is used for the treatment of epilepsy. May cause a potentially dangerous rash that may develop into Stevens Johnson syndrome, an extremely rare but potentially fatal skin disease. Signs of overdose include confusion (severe), decrease in or loss of reflexes, drowsiness (severe), fever, irritability (continuing), low body temperature, poor judgment, shortness of breath or slow or troubled breathing, slow heartbeat, slurred speech, staggering, trouble in sleeping, unusual movements of the eyes, weakness (severe). 2009-07-21T20:26:57Z 2026-04-03T02:49:25Z Metharbital 102408 Metharbital DB00463 true CCC1(CC)C(=O)NC(=O)N(C)C1=O C9H14N2O3 InChI=1S/C9H14N2O3/c1-4-9(5-2)6(12)10-8(14)11(3)7(9)13/h4-5H2,1-3H3,(H,10,12,14) FWJKNZONDWOGMI-UHFFFAOYSA-N 198.2191 198.100442324 Exogenous Solid 1.15 HMDB14606 CHEMBL450 3957 CHEM002200 DTXSID6023280 NS00016843 5,5-diethyl-1-methyl-1,3-diazinane-2,4,6-trione