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Butabarbital
- indication:For short-term treatment of insomnia and anxiety disorders
- pharmacologypharmacology:
- mechanism: Butabarbital binds at a distinct binding site associated with a Cl<sup>-</sup> ionopore at the GABA<sub>A</sub> receptor, increasing the duration of time for which the Cl<sup>-</sup> 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.
- toxicity: 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).
- absorprion:
- halflife:
- roouteelimination: Barbiturates are metabolized primarily by the hepatic microsomal enzyme system, and most metabolic products are excreted in the urine.
- volumedistribution:
- clearance: