PPT- Anxiety, Sibstance Misuse, Stress Disorders Flashcards
Whats the pharmacological treatment options for GAD?
SSRI - sertraline is first line (other options are escitalopram or paroxetine)
Whats the pharmacological treatment options for acute stress disorder or PTSD?
Antidepressant - paroxetine or mirtazepine
Consider short term benzos for help sleeping
Whats the risk of giving benzos in acute stress disorder?
There is a link between giving benzos for >2 weeks and increasing the risk of ASD progressing to PTSD
Outline the MOA of SSRI?
In the acute situation it prevents reuptake of serotonin from the synaptic cleft which increases the amount of serotonin at the end plate which reduces neuron firing
In the chronic situation this process adapts and you end up with increased firing
What are the important side effects of SSRIs?
Anxiety
Arthralgia
Impact on appetite + may increase weight
GI side effects
Sleep impact
Constipation
Dizziness
QT interval prolongation
Hyponatraemia
What are other considerations for SSRIs?
Serotonin syndrome risk (especially with poly pharmacy)
Must be withdrawn gradually
Can increase the risk of bleeding - particularly GI bleeding if used alongside NSAIDs
Whats the moa of benzodiazepines?
They bind to the GABA-A receptor =conformational change = enhances the affinity of GABA for its binding site on the receptor = increase in the influx of CL- into the neuron = hyperpolarizes the cell membrane and makes it less likely to fire an action potential
Why were benzos invented?
To replace barbiturates - considered safer in overdose as they have a wider therapeutic window
What are the useful efefcts of benzos?
Sedation - reduced sensory input to the reticular activating system
Sleep induction (hypnosis) at high concentrations
Anterograde amnesia
Anxiolysis
Anticonvulsant activity
Reduces muscle tone
Give examples of when the anterograde amnesia properties of benzos is used?
Date rape drug (flunitrazepam) aka rohypnol
Midazolam for endoscopy so you cant remember it’s unpleasant
How should you manage a pt displaying violent or aggressive behaviour?
Options include:
Manual restraint
Rapid tranquilisation
Seclusion
Mechanical restraint in high-secure setting
What can be used for rapid tranquilisation?
IM lorazepam
IM haloperidol and promethazine
When is IM lorazepam used first line for rapid tranquilisation?
If uncertain antipsychotic drug history
If cardiac history or no ECG to exclude it
What are the risks of using benzos for rapid tranquilisation?
Loss of consciousness
Respiratory depression
CV collapse
Disinhibition
What are the risks of using antipsychotics for rapid tranquilisation?
Loss of consciousness
CV and respiratory complications/collapse
Seizures
Acute dystonia reactions
NMS
Excessive sedation
What monitoring should be done after rapid tranquilisation?
Every 15 minutes for at least 1 hour there should be intense monitoring - temp, pulse, BP, hydration, consciousness level and RR
The pt muster remain under eyesight observation until they are fully ambulatory again
Where does ethanol act in the brain?
Ethanol can bind to specific sites on the GABA-A receptor complex, including the alpha subunits, and enhance the activity of the receptor, leading to increased chloride ion influx and further inhibition of neural activity. This is thought to contribute to the sedative and anxiolytic effects of ethanol, as well as its potential for abuse and dependence.
It is worth noting that ethanol can also act on other ion channels and receptors in the brain, such as NMDA glutamate receptors, serotonin receptors, and voltage-gated calcium channels.
How should you manage alcohol withdrawal?
A reducing course of Chlordiazepoxide if they typically drink 15 units of alcohol a day or more
Pabrinex IV for those at high risk of wernickes. Otherwise thiamine oral and multivitamins
Why is chlordiazepoxide the benzo of choice for alcohol withdrawal?
Mainly because it has a longer half life than other benzos which allows for a more gradual and sustained reduction in sympotms
Howe many daily units of alcohol put you at the highest risk of DT or alcohol withdrawal seizures?
30 units or more
Why should pt with hypoglycaemia and evidence of chronic alcohol ingestion always be given IV pabrinex?
As hypoglycaemia increases the risk of wernickes!
Which patients are at high risk of wernickes?
Those who present with significant weight loss + signs of under nutrition
Severe withdrawal
Increasing memory problems and black outs
Coma or confusion
Patients with hypoglycaemia
How should you manage sleep difficulties in alcohol withdrawal?
Sleep hydneein
Consider loading the total daily dose of chlordiazepoxide towards the evening
How should you manage nausea in alcohol withdrawal?
Metoclopramide
How should you manage diarrhoea in alcohol withdrawal?
Loperamide
How should you manage itching in alcohol withdrawal?
Check for liver disease and consider chlorpheniramine
What are the main differences between lorazepam and chlordiazepoxide?
Chlordiazepoxide has a longer half life than lorazepam- lorazepam is therefore more suitable for acute symptoms
Lorazepam has a faster onset of action
Chlordiazepoxide is more potent
Chlordiazepoxide is only available in oral form whereas lorazepam is available IV and oral
What are indications for lorazepam?
Acute sedation
Status epilepticus
What opioid agonists are used for opioid misuse?
Methadone
Buprenorphine
What opioid antagonists are used for opioid misuse?
Naltrexone
How do opioid agonists work to manage opioid misuse?
They block the acute efefcts of other opioids and suppress craving and withdrawal symptoms
It reduces antisocial behaviours, address the problems and allows the pt to return to a productive lifestyle
What are the differences between methadone and Buprenorphine?
Methadone is a long-acting opioid agonist that binds to my-opioid receptors. Buprenorphine is only a partial mu-opioid agonist
Methadone reduces the euphoric effects of subsequent illicit optic use
Buprenorphine produces less of a ‘high’ and has a lower risk of overdose
Buprenorphine is a ‘ceiling effect’ drug which makes it safer
What is naltrexone used for?
As an Adjunct to prevent relapse in detoxified formerly opioid-dependant people
Good for highly motivated people who wish to remain abstinent
What drugs can be offered for nicotine dependance?
NRT
Bupropion
Varenicline
Whats the moa of bupropion?
Enhances mesocorticolimbic dopaminergic activity and nicotine receptor antagonist activity
Whats the moa of varenicline?
Partial agonist of nicotine receptors
Highly selective for CNS receptor subtypes involved in addiction
Outline the toxidrome of opioids overdose?
Resp depression
Bradycardia
Hypotension
Pin point pupils
Reduces bowel sounds
Fatigue
Outline the toxidrome of cocaine and amphetamine overdose?
Increase RR, HR and BP
Pupillary dilation
Sweating
Increased energy
Outline the toxidrome of benzo overdose?
Reduced RR, HR and BP
Normal pupils
No bowel sounds
Fatigue
Outline the toxidrome of anticholinergic overdose?
Increase HR and BP
Pupil dilation
Fever
No bowel sounds
Increased energy
Outline the toxidrome of cholinergic overdose?
Pin point pupils and sweating
Whats the antidote for opioids?
Naloxone
Whats the antidote for TCAs?
Sodium bicarbonate
Whats the antidote for benzos?
Flumazenil
Whats the antidote for ethylene glycol or methanol?
Fomepizol
(Ethanol is second line)
Whats the moa of fomepizol?
Competetitive inhibitor of alcohol dehydrogenase = fomepizole slows down the formation of toxic metabolites such as glycolic acid and oxalic acid, which are responsible for the metabolic acidosis and renal failure that can occur with ethylene glycol and methanol poisoning.
Opioid and benzo overdose look very similar, if not the same. How should you manage this and why?
You can trial naloxone for opioid overdose. Dont try Flumazenil as this can be very dangerous if the pt has had a mixed overdose
When’s the only time Flumazenil will be used?
In controlled situations e.g. an anaesthetics gives slightly too much midazolam for endoscopy and needs to reverse the efefcts.
What are the adverse effects of clozapine?
Agranulocytosis
Reduced seizure threshold
Constipation
Myocarditis
Hypersalivation
NMS
