Psychiatric Medication - anxiolytics Flashcards
Examples of anxiolytics
- Beta blockers
- Benzodiazepines
- Pregabalin
- Antidepressants
Beta blockers for anxiety MOA
- Affect bio-psycho-feedback - interrupt cycle of brain affecting behaviour
- For when nerves affect performance
- Limited effectiveness
Danger of propanolol
- Overdose
- Can cause arrhytmias
- Contraindicated in asthma
What kinds of people often can misuse beta blockers?
- Professional musicians
- Snooker players
- Actors
Benzodiazepines use
- Diazepam (long hald life)
- Lorazepam (shorter half life, more dependence forming)
- Bind to GABA receptors to potentiate effect of GABA - positive allosteric modulators = neurones less excitable
Risk of benzodiazepines
- Tolerance and dependence - max use 6 weeks sometimes recommended, but can be used for longer if non dependence issue (usually short term)
- Significant potential for misuse - use for single event - need trial run previous to this (check sedation and PD, potentiates alcohol - avoid)
- Occasionally can cause paradoxical disinhibition
What is paradoxical inhibition?
- Give something to make someone calm and it actually makes someone become more agitated
- Often seen in lower doses in people of older age
- Amygdala root of emotional processing, frontotemporal region controls how much the emotion is shown - knock out FT but amygdala remains
MOA pregabalin
- Binds to voltage gated calcium channels on neurones
- Reduces neuronal activity (CNS depressant)
- Used for anxiety, neuropathic pain and epilepsy
Risk of pregabalin
- Less potential for misuse and dependence and tolerance than benzos
- But still misused - chopped up and sniffed
- BNF says should be short term
- Sedation
- Weight gain
First line meds for anxiety
- SSRIs
Examples of hypnotics - sleeping tablets
- Benzodiazepines - Temazepam, Lormetazepam, Nitrazepam
- Non-benzodiazepines - still allosteric positive modulators of GABA but structured different eg Zopiclone and Zolpidem (also called Z drugs)
Benzos vs nonbenzodiazepines hyponotics
- Not much difference between two groups
- Z groups often favoured
- Both significant potential for misuse, dependence and rebound insomnia
What is rebound insomnia
- Sleep disturbance that occurs when person stops taking sleeping medication
- Becomes worse than it was before starting medication
Max duration of hypnotics
- Only for 2 weeks
- Take for only 5 out of 7 days each week - reduce potential tolerance (get receptor downregulation)
Mood stabilisers
- Used for bipolar disorder
One of:
* Lithium - one of most effective mood stabilisers
* Anticonvulsants
* Second generation (atypical) antipsychotics
Lithium MOA
- Unknown - does lots of thinks
- Lowers noradrenaline release and increases serotonin synthesis
- Also used to augment antidepressants
Cautions with lithium
- Narrow therapeutic window
- Need regular serum levels - weekly after dose change intil level stable
- Then 3 monthly once stable
- Entirely excreted by kidneys (none metabolised by liver)
Lithium effect on suicide
- Significant evidence that it reduces suicide
- Has a licence for this
- Can be given to suicidal people (eg with EUPD)
Side effects (short term) lithium
- GI disturbance (esp on initiation)
- Metallic taste in mouth (is metal)
- Dry mouth
- Fine tremor
- Polydipsia
- Polyuria
- Weight gain
(usually give at night, can cause anuresis)
Long term effects Lithium and monitoring
- Hypothyroidism - reversible (can stop drug or give levothyroxine and continue)
- Renal impairment - irreversible, occurs mostly above therapeutic doses
- THEREFORE - need annual U&Es and TFTs
- Lithium level every 3 months (via lithium register)
Symptoms of lithium toxicity
- Confusion
- Coarse tremor
- N+V
- Ataxia
- Seizures
Management of lithium overdose
- Stop lithium
- IV fluids
- Dialysis if needed
- Benzodiazepines if seizures
What can increase risk of lithium toxicity?
- Dehydration - advise to drink lots of water in hot climates
- Lithium does not come out in sweat
Drug interations with lithium
- NSAIDs - if increase NSAIDs, lithium levels likely go up
- Loop diuretics
- ACE inhibitors
If change dose of one, may affect the concentration of other
Second generation antipsychotics used for bipolar mood disorder
- Quetiapine used first line - more due to problem witb lithiums narrow TI rather than better efficacy
- All have effectiveness
- Doses and monitoring same for psychosis
Anticonvulsants used for mood stabilisers - examples and risk
- Sodium valproate - avoid in women in child bearing age and men, check LFTs soon after starting
- Carbamazepine - less effective, very sedating
- Lamotrigine - Stevens Johnson syndrome
Risk of all anticonvulsants
- Thrombocytopenia - check FBC
- Sedation
- Weight gain
Problem with SV and Carbamazepine
Interact with LOTS of drugs - caution with doses of other drugs and of drug itself
What is SJS?
- Type 4 hypersensitvity reaction
- Dermatological emergency - blistering of skin (esp in eyes, vagina, lips, lining liver)
- Stop agent - urgent dermatologist review
- Can cause visual impairment
Drugs used to treat ADHD - classes
- CNS stimulants
- As people with ADHD are neurologically understimulated so then do things to try and stimulate brain
Examples of CNS stimulants used for ADHD
- Methylphenidate - most common, often given a combinatiion of immediate and sustained release
- Dextroamphetamine
Risks with CNS stimulants
- Potential for misuse and dependency
- Need to monitor weight, height and pulse - suppress appetite and can stunt growth in children (can do drug holidays for this)
Alternative of CNS stimulants for ADHD if not working or history of drug misuse or patient preference
- Atomoxetine
- Noradrenaline reuptake inhibitor
Withdrawal symptoms of benzodiazepines include
- Depersonalisation
- Perceptual alteration
- Vomitting
