Antianxiety Agents Flashcards
(22 cards)
- a multisystem response to a perceived threat or
danger. It reflects a combination of biochemical changes in the body, the patient’s personal history and memory, and the social situation
Anxiety
- medicines that calm and relax people with
excessive anxiety, nervousness, or tension, or for short-term control of social phobia disorder or specific phobia disorder - used to treat mild transient bouts of anxiety as well as
more pronounced episodes of social phobia and specific phobia - minor tranquilizers
Antianxiety drugs
- most commonly used anxiolytics and
hypnotics - act at benzodiazepine receptors, which are associated with gamma-aminobutyric acid (GABA) receptors
Benzodiazepines
At least three distinct binding sites for the
benzodiazepines:
- GABA-A receptor
- the benzodiazepine receptor
- the binding site for the barbiturates
True
modulate the activity of
gamma-aminobutyric acid (GABA) in the brain and may be responsible for the inhibitory effect
Benzodiazepines
- anxiolytics potentiate a major
inhibitory neurotransmitter called - causes a reduction in the excitability of the central nervous system
gamma-aminobutyric acid (GABA)
MOA: chloride channel opens and allows Cl– ions in, hyperpolarizing
the cell and making it less excitable.
- allosterically alters the shape of the GABA
site so that it fits GABA better, it has a greater affinity for the
GABA molecule.
Benzodiazepines
Hallmarks of Benzodiazepines
- anti-convulsant
- muscle relaxant
- anti-anxiety
Almost all active
benzodiazepines, except
those possessing a fused
heterocyclic ring or a
thionyl group, have a
carbonyl group at position
2
T
A benzene ring, separated from the heterocyclic benzodiazepine ring
system by a single bond. A benzene ring is called a ________ when it is
part of a larger molecule.
phenyl group
There must be an electron withdrawing
substituent at _____________. The halogens : chlorine, flourine, bromine, and iodine are nice attractors of electrons.
Position 7
Addition of methyl group to the nitrogen at position 1, yields a
prototype benzodiazepine diazepam
T
- triazolo compound do not require any substitution at
position 7 to stabilized its potency. - Positions 6, 8, and 9 should be left unsubstituted.
T
The presence of a phenyl at the 5-position increases activity, and all benzodiazepines have this substituent.
5-Phenyl ring with electron-attracting groups at the 2′ position show greatly increased activity, and produce greater amnesia (lorazepam, and compare alprazolam and triazolam) while 4′ (para) substitution decreases or abolishes activity.
T
- 4, 5 double bond should not be moved or saturated.
- The N-substituent at position 1 should be small for higher intrinsic activity; however, drugs with large substituents at this position have been prepared and marketed (e.g., flurazepam, prazepam, halazepam, not shown).
They owe their activity to metabolic dealkylation, often to nordazepam.
T
- 7-chloro-5-(2-chlorophenyl)-1,3-dihydro-3-
hydroxy-1,4- benzodiazepin-2-one
Lorazepam
Occurs as white, crystalline, water-insoluble
powder
Lorazepam
- 7-chloro-1, 3-dihydro-1-methyl-5-phenyl-2H-1,4-
benzodiazepin-2-one
Diazepam
- white or almost white, crystalline powder
- very slightly soluble in water
- soluble in alcohol
Diazepam
indicated for the short-term relief (two to
four weeks only) of anxiety that is severe, disabling or
subjecting the individual to unacceptable distress, occurring
alone or in association with insomnia or short-term
psychosomatic, organic or psychotic illness.
Benzodiazepines
T or F
use of benzodiazepines to treat short-term mild anxiety is inappropriate and unsuitable
T
T or F
Common side effects of Benzodiazepines:
Mental slowing, sedation, blurred speech, blurred vision,
anorexia, nausea, vomiting, dry mouth, diarrhoea, and
constipation
T
