PH3113 - Psychiatric Disease and its Pharmacology 2 Flashcards
What are the different treatments for anxiety?
Psychotherapy
Medication
- benzodiazepines
- anxiolytic
- anti-depressants
- anti-epileptics
- anti-psychotics
- buspirone
- propranolol
- barbiturates
- no longer used for anxiety
- used to be used in low doses to calm people down
What is the NICE stepped care plan for Generalised Anxiety Disorder (GAD)?
Step 1
- all known and suspected presentations of GAD
- identification
Step 2
- diagnosed GAD that has not improved after step 1 interventions
- low-intensity psychological interventions for GAD
Step 3
- GAD with marked functional impairment or that has not improved after step 2 interventions
- treatment options either
- individual high-intensity psychological intervention
- counselling
- drug treatment
Step 4
- complex treatment-refractory GAD and very marked functional impairment such as self-neglect or a high risk of self-harm
- highly specialised treatment
- complex drug and/or
- psychological treatment regimens
- input from
- multi-agency teams
- crisis services
- day hospitals
- inpatient care
Give examples of psychotherapy as a first line treatment in all anxiety disorders
Cognitive Behavioural Therapy (CBT)/Applied relaxation
Self help
Psychoeducational groups
How are benzodiazepines used to treat anxiety?
Most commonly used anxiolytics and hypnotics
Short term relief of anxiety that is severe, disabling or causing the patient unacceptable distress
- two to four weeks only
Use to treat short-term ‘mild’ anxiety is inappropriate
What schedule are benzodiazepines used to treat anxiety?
Schedule 4 CDs
- apart from temazepam
Schedule 3 CD No Reg and midazolam
Schedule 3 CD No Reg exempt safe custody
What are the pharmacological effects of benzodiazepines?
Sedation
- sleep induction but permitting arousal
Decreased anxiety
Amnesia at higher doses
- helpful for recent traumatic events
Muscle relaxation
- midbrain and spinal effects
Anticonvulsant activity
Reduced aggression
How do benzodiazepines treat anxiety?
When you bind Benzodiazepines to the GABA(A) receptor in the presence of GABA you get an increased frequency of channel openings causing a greater influx of chloride ion, hyperpolarisation of neurone leading to dampening down of neuronal activity
Benzodiazepines modulate the action of GABA at GABA(A) receptors containing the alpha(n), gamma(2) motif
Single channel studies show
- increased frequency of channel openings
- allosteric modulator
- no change in conductance
- no change in mean open time
- not open longer
Benzodiazepines stabilise the active form of the receptor
- greater influx of chloride ion
- hyperpolarisation of neurone
- dampens down neuronal activity
What are the 3 classifications of benzodiazepines and give examples?
Short acting
- half life < 8 hrs
- triazolam
- temazepam
- oxazepam
- lormetazolam
Intermediate acting
- half life 10 - 18 hours
- lorazepam
Long acting
- half life > 20 hours
- diazepam
- chlordiazepoxide
- nitrazepam
- flurazepam
- flunitrazepam
How are benzodiazepines metabolised?
Most are well absorbed after oral dosing
All are widely distributed
Plasma levels decline
- hepatic metabolism
- intermediates may be active
- inactive, water soluble conjugates
- glucuronides
Renal excretion of inactive glucuronides
Hepatic function, not renal function, is the important determining factor for potency and duration of action
What are the adverse effects of benzodiazepines?
Sedation
Ataxia
- unsteady gait with high doses
Potentiation of alcohol and other CNS depressants
Interference with motor skills
- impaired dexterity and speed of response
- reduced awareness
Tolerance
Withdrawal symptoms
- anxiety!
Dependence
Irritability and aggression
- particularly with ultra-short acting triazolam
- withdrawal symptom
- more acute with drugs whose action wears off rapidly
- withdrawn in the UK
What are the withdrawal symptoms of benzodiazepines?
Increased anxiety
- ironic!
Insomnia
Dysphoria
Irritability
Sweating
Unpleasant dreams
Tremors
Anorexia
Faintness/dizziness
How can the withdrawal symptoms of benzodiazepines be reduced?
Avoiding when history of alcohol abuse or previous problems with prescribed sedatives
Not prescribing short-acting drugs from continuous medication
Not prescribing other agents at high doses
Arranging a planned withdrawal
- reducing regime
- long acting benzodiazepine
Substituting with
- sedative tri-cyclic antidpressants
- amytriptyline
- anti-psychotic
- chlorpromazine
What is the withdrawal protocol of benzodiazepines?
Benzodiazepine can be withdrawn in steps of one-eighth of the daily dose every fortnight
- one-tenth to one-quarter
Transfer patient to equivalent daily dose of diazepam
- preferably taken at night
Reduce dose every 2-3 weeks
- if withdrawal symptoms occur, maintain this dose until symptoms improve
Reduce dose further
- if necessary in smaller steps
- it is better to reduce too slowly than too quickly
Stop completely
- full withdrawal can take 4 weeks to a year or more
Give examples of Selective Serotonin Reuptake Inhibitors (SSRIs)
Paroxetine
Citalopram/escitalopram
Sertraline
Which drugs are first line drug options in treating Generalised Anxiety Disorder (GAD), panic disorder, social phobia, PTSD and OCD?
Selective Serotonin Reuptake Inhibitors (SSRIs)
