Anxiety + Insomnia: Pathophysiology + Pharmacology Flashcards
Are anxiety + insomnia interlinked?
YES
What is anxiety?
Worried, tense or afraid about things that are about to happen, or which could happen
What’s the difference between anxiety + fear?
Anxiety = unknown threat
Fear = definite threat
How can anxiety be experienced?
Thoughts, feelings and physical sensations
What is an example of physical sensations of anxiety?
Increased HR
Increased BP
What is anxiety often a comorbidity of?
Mental health disorders
eg. schizophrenia
What are the psychological symptoms of anxiety?
Restlessness
Difficulty concentrating
Irritability
What are the physical symptoms of anxiety?
Fatigue
Muscle aches + tension
Insomnia
What are the behavioural symptoms of anxiety?
Avoidance
Engaging in unhealthy, risky or self-destructive behaviours
Becoming overly attached
What are the different types of anxiety disorders?
General anxiety disorder (GAD)
Panic disorder
Specific phobias
Social anxiety disorder
PTSD
OCD
What is panic disorder?
Scared of something - eg. an exam
BUT goes away after the exam has finished
How do you diagnose anxiety?
Has to be most days for at least 6 months
Significant distress in social, occupational or important areas
NOT due to medical condition or substance
How does stress happen?
Hypothalamus releases CRH
Acts on pituitary gland
Pituitary gland releases ACTH
Acts on adrenal gland
Releases cortisol
STRESS
What is the response to stress?
Increased cardiovascular tone
Suppression of digestion
Suppression of growth
Suppression of reproduction
Alter immune system
Sharpening of cognition
What is the overall treatment for anxiety?
Changes in lifestyle
Self-help
Psychotherapy
Pharmacotherapy
What is the 1st line treatment for anxiety?
SSRIs (selective serotonin reuptake inhibitors)
SNRIs (serotonin + norepinephrine reuptake inhibitors)
What is the 2nd line treatment for anxiety?
Tricyclic antidepressants
5-HTA agonist
Monoaminoxidase inhibitors
What is the 3rd line treatment for anxiety?
Benzodiazepines
What are examples of SSRIs?
Citalopram
Fluoxetine
Paroxetine
What are the advantages of SSRIs?
Effective against various types of anxiety disorders
Long lasting
Less addictive than benzodiazepines
Potent
Fewer side effects
What are disadvantages of SSRIs?
Delay period (2-6 weeks)
Health issues if taken with other drugs
Why is there a delay period in SSRIs?
Receptors on pre-synaptic
Binds
= inhibits further release of serotonin
BUT after weeks auto-receptors desensitise
What are the side effects of SSRIs?
Insomnia
Nausea
Dizziness
Sexual dysfunction
Serotonin syndrome
What does SNRIs do?
Increase both serotonergic + noradrenergic transmission
Does SNRIs have more or less side effects than SSRIs?
LESS
What are examples of SNRIs?
Duloxetine
Venlafaxine
What are TCAs antagonists of?
5-HT receptors
Alpha1 adrenergic receptor
Histamine receptor
Muscarinic cholinergic receptor
What does it mean that TCAs are antagonists of lots of receptors?
Have LOTS of side effects
What are examples of TCAs?
Clomipramine
Imipramine
What are side effects of TCAs?
Dry mouth
Sedation
Weight gain
Constipation
Dizziness
Heart rhythm problems
What is the mechanism of action of SSRIs + SNRIs?
Promote neuroplasticity
= promotes flexibility + make the brain more capable of changing
= brain resists anxiety
What are benzodiazepines mechanism of action?
Activate GABA
= hyperpolarisation
= inhibits neurone
= sedative drug
What are the advantages of benzodiazepines?
Quick onset
What are the disadvantages of benzodiazepines?
Highly addictive
Withdrawal symptoms
Impaired cognitive function
What criteria needs to be considered when choosing an anxiety drug?
Particular symptoms
Side effects
Whether one worked for a close relative
Interaction with other medications
Pregnancy
Other health conditions
What is insomnia?
Difficulty falling asleep or staying asleep
What is short term insomnia?
Less than 3 months
What is long term insomnia?
3 months or longer
What are the cause of insomnia?
Stress
Psychiatric conditions (depression, schizophrenia)
Other medical conditions (Alzheimer’s)
Medications (SSRIs)
What sets the clock for your brain?
Suprachiasmatic nucleus (SCN)
What also influences your sleep?
Light exposure
= tells you if night/day based on light let into eye
What is the sleep-wake cycle?
Arousal
REM
Timing
Consolidation
What happens in wake promoting circuits?
Neurons release serotonin, noradrenaline, dopamine, Ach + histamine
Why is it significant that serotonin is released in the wake promoting circuit?
SSRIs can cause insomnia
What happens in NREM promoting circuits?
GABA is released in forebrain
What happens in REM promoting circuits?
GABA released into brainstem
= stays asleep
What is the treatment for insomnia?
Changes in sleep pattern/lifestyle
Tackle stress/anxiety
Psychotherapy
Pharmacotherapy
Which hypnotic was originally used to treat insomnia?
Barbiturates
Why aren’t barbiturates not used to treat insomnia anymore?
Narrow therapeutic window
Easy to overdose
Fatal if combined with antidepressants, alcohol + other drugs
What were barbiturates replaced with?
Benzodiazepines
What are examples of benzodiazepines?
Diazepam
Loprazolam
Midazolam
What are the other drugs that can be used to treat insomnia?
Z drugs - eg. Zolpidem
Antihistamines - eg. diphenhydramine
Melatonin
