Pharmacology of Anxiolytics Flashcards
Drugs used to treat anxiety
Benzodiazepines Antidepressant drugs Busiprone (anxiolytic) Pregabalin B-Blockers (propanolol)
Co-morbidities of anxiety
Substance abuse ADHD Bipolar Pain disorder Sleep disorder
symptoms of anxiety
Fear (panic, phobia)
Worry (anxiety, apprehension, obsessions)
What is GABA?
Main inhibitory neurotransmitter in brain (benzodiazepines enhance GABA action)
Circuit responsible for fear part of brain
Amygdala-Centred Circuit
GABA-A (main receptor) targeted by …
Benzodiazepines, barbiturates + alcohol (has allosteric affect on GABA so increasing inhibition)
examples of benzodiazipines:
Lorazepam
Diazepam
Pharma effect of benzodiazipines:
Reduce anxiety Hypnosis/sedation Muscle relaxation Anticonvulsant effect Anterograde amnesia
Clinical uses of benzos:
Acute treat extreme anxiety Hypnosis Alcohol withdrawal Mania Delirium Rapid tranquillisation Before surgery Status epilepticus
problems with benzos
-Fairly safe in overdose (unlikely to lead to resp depression)
BUT
-can increase aggression (paradox)
-Anterograde amnesia (new memories)
-Tolerance and dependence SO SHORT TERM USE RECOMMENDED (2-4 WEEKS)
causes of withdrawal symptoms =
rapid withdrawal (confusion, psychosis, tachy, tremor) Neuroadaptation of GABA response (chronic treatment > anxiety/convulsions)
How to withdraw benzodiazepines
reduce dose every 2-3 weeks in steps of 2-2.5mg (if symptoms occur maintain dose until improvement)
role of serotonin
- key neurotransmitter that innervates amygdala
- SSRIs + SNRIs increase serotonin by blocking the serotonin transporter
How antidepressants treat anxiety?
Acutely (SSRIs increases serotonin)
Chronically (Anxiolytic properties appear)
What is pregabalin?
Ca channel blocker
GABA enhancer
only considered if not responsive to other treatments
