Benzeneringz
12-06-2006, 21:29
Benzodiazepines are a class of drugs used medically for their anxiolytic, anticonvulsive, sedative, and myorelaxant properties. Another property of the benzodiazepines, amnesia, is not sought after medically. Different benzodiazepines have different strengths and weaknesses, depending on their affinity for GABA(A) receptors. Let me discuss this in further detail.
GABA(a), GABA(b), and GABA(c)
Gamma-aminobutyric acid (GABA) is the most widespread inhibitory neurotransmitter found in the brain. GABA works by reducing the action potential of a cell which prevents it from firing. Drugs that work on GABA receptors include the barbiturates, benzodiazepines, baclofen, gabapetine (Neurotonin), imidazopyridines-zopiclone & zolpidem, GHB, valproate, and many more. There are three types of GABA-receptors: A, B, and C. The benzodiazepines bind to GABA(A), while baclofen (Lioresal) binds to GABA(B). Neuroactive steroids are thought to bind to GABA(C).
GABA(a) sub-receptors
There are five sub-receptors of the sub-receptor GABA(A). These subreceptors determine the actions of a benzodiazepine. For example, benzodiazepines with a high affinity for GABA(A) A1, also known as alpha-1, are highly sedating. Alpha-2 ligands are powerful anxiolytics. Each benzodiazepine has a slightly different affinity profile which makes each benzodiazepine unique!
What about zolpidem?
Zolpidem and related compounds (zaleplon, zopiclone, eszopiclone) are often referred to as 'non-benzodiazepine hypnotics' but are considered to have many properties in common with the benzodiazepines. This is easy to decipher. Zolpidem has little affinity for alpha-2,3,4,&5 subreceptors. It's primary binding to alpha-1 makes it a benzodiazepine-type sedative and nothing more. Anxiolytic and anticonvulsive properties only are apparent at 10-20the theraputic dose of 5-10 milligrams (1).
1. http://en.wikipedia.org/wiki/Zolpidem
GABA(a), GABA(b), and GABA(c)
Gamma-aminobutyric acid (GABA) is the most widespread inhibitory neurotransmitter found in the brain. GABA works by reducing the action potential of a cell which prevents it from firing. Drugs that work on GABA receptors include the barbiturates, benzodiazepines, baclofen, gabapetine (Neurotonin), imidazopyridines-zopiclone & zolpidem, GHB, valproate, and many more. There are three types of GABA-receptors: A, B, and C. The benzodiazepines bind to GABA(A), while baclofen (Lioresal) binds to GABA(B). Neuroactive steroids are thought to bind to GABA(C).
GABA(a) sub-receptors
There are five sub-receptors of the sub-receptor GABA(A). These subreceptors determine the actions of a benzodiazepine. For example, benzodiazepines with a high affinity for GABA(A) A1, also known as alpha-1, are highly sedating. Alpha-2 ligands are powerful anxiolytics. Each benzodiazepine has a slightly different affinity profile which makes each benzodiazepine unique!
What about zolpidem?
Zolpidem and related compounds (zaleplon, zopiclone, eszopiclone) are often referred to as 'non-benzodiazepine hypnotics' but are considered to have many properties in common with the benzodiazepines. This is easy to decipher. Zolpidem has little affinity for alpha-2,3,4,&5 subreceptors. It's primary binding to alpha-1 makes it a benzodiazepine-type sedative and nothing more. Anxiolytic and anticonvulsive properties only are apparent at 10-20the theraputic dose of 5-10 milligrams (1).
1. http://en.wikipedia.org/wiki/Zolpidem