Pharmacology of Anxiolytic Drugs Flashcards
What is the general overall mechanism of benzodiazepines?
Act at GABA-A receptor to increase action of GABA causing an inhibitory effect
List the pharmacological clinical effects of benzodiazepines
Reduce anxiety and aggression Hypnosis, sedation Muscle relaxation Anticonvulsant effect Anterograde amnesia
Which BZD acts as a GABA receptor antagonist and what is its effect on anxiety?
Flumazenil
Increases anxiety
Some people can develop tolerance to BZD’s - what is the significance of this? How long should BZDs be used for?
The doses that work for them can be lethal in normal people
2-4 weeks
List the clinical effects of rapid withdrawal of BZD’s
Confusion, psychosis
Convulsions
Tachycardia, sweating, hypertension
Agitation, tremor
List drugs used to treat anxiety
Benzodiazepines Antidepressants (SSRIs, TCADs, SNRIs, MAOI) Buspirone Pregabalin B blockers (propranalol)
What is the effect of GABA on the receptor?
Has a positive allosteric effect
Neurone less likely to fire action potential in amygdala and CSTC circuit
Which part of the brain has a role in controlling fear?
Amygdala
Which part of the brain has a role in controlling worry?
Cortico-striato-thalamo circuit
How long should benzodiazepines be used for? Why?
2-4 weeks maximum due to issue of dependance
Chronic treatment leads to reduced response to GABA and possibly increased anxiety
Give examples of the main benzodiazepines used clinically
Lorazepam
Diazepam
Chlordiazepoxide
(Have different durations of action on GABA receptor)
List other clinical uses of bezodiazepines, aside from anxiety
Alcohol withdrawal
Mania
Delirium
Status epilepticus
List features of benzodiazepine withdrawal
Abdominal cramps
Anxiety, panic attacks
Muscle tension, chest pain, palpitations, sweating, shaking
Blurred vision
Depression, insomnia, nightmares
Dizziness, headaches, inability to concentrate
Nausea, vomiting
Tingling in hands and feet, sensory sensitivity
Restlessness
How should benzodiazepines be withdrawn safely?
Transfer to daily dose taken at night
Reduce dose every 2-3 weeks by small amounts
Stop completely, withdrawal from 4wks - 1yr
Propranolol is useful for treating what type of symptoms in anxiety?
Somatic symptoms - palpitation, tremor
Outline the six management options for GAD, starting with 1st line
- Psychoeducation
- Self-help and group sessions
- High intensity psychological treatment (CBT) or drug treatment (SSRI, benzodiazepines in ST)
- SNRI
- Pregabalin
- Combo of CBT and drugs
Drug treatment for GAD should be tried for _____ and continued for _____
12 weeks
18 months
Outline the three management options for panic disorder, starting with 1st line
- Self-help
- CBT or SSRI if LT or no response to CBT
- TCADs (clomipramine, desipramine, imipramine, tofepramine)
Which drugs should be avoided in panic disorder?
Benzodiazepines Sedating antihistamines Propranalol Buspirone Buprapion
Outline the six management options for OCD, starting with 1st line
- Low intensity psychological treatment (CBT, ERP, self-help)
- High intensity psychological treatment or SSRI (fluoxetine, paroxetine, sertraline, citalopram for 1yr)
- Consider increasing dose after 4-6 weeks
- SSRI + CBT + ERP
- Clomipramine
- Augmentation with antipsychotic or clomipramine + citalopram
Outline the four management options for PTSD, starting with 1st line
- Mild + <4 weeks from trauma = watchful waiting
- Within 3 months of trauma = brief psychological intervention (trauma focused CBT) and hypnotic meds for sleep disturbance
- > 3 months after trauma = trauma focused CBT or EMDR
- Drugs - paroxetine or mirtazepine
amitryptiline or phenelzine (MH specialist)
Outline the five management options for social anxiety, starting with 1st line
- Individual CBT
- SSRI (escitalopram or sertraline) - review at 12 weeks
- SSRI + CBT
- Alternative SSRI (fluvoxamine or paroxetine) or SNRI (venlafaxine)
- MAOI inhibitor (moclebemide)
