3. Mental health disorders Flashcards
Anxiety symptoms
fear
restlessness
irritability
difficulty cocentrating
phyiscal
tremors
palpitations
muscle tension
excessive sweating
shortness of breath
insomnia
Anxiolytic drugs
Benzodiazepines
5-HT3 agonist
Antidepressant
Antiepileptic
Antipsychotic
Beta-blockers (help with the physical symptoms of anxiety such as tremors, palpitations and muscle tension)
- propanolol
- oxprenolol
Benzodiazepines mechanism of action
Acts on binding sites on GABA-a receptors to enhance binding of GABA.
GABA is an inhibitory neurotransmitter causing widespread CNS depressant effects: reduced axiety, muscle relaxation, anticonvulsant, sedation
Benzodiazepine uses
- severe anxiety (short term)
- muscle spasm
- seizures
- insomnia
Benzodiazepines caution/contraindication
Should be avoided in elderely patients, if ESSENTIAL, half the dose and use it for half the required period
Should be avoided in mild liver impairement as their sedative effects, can cause hepatic coma.
if ESSENTIAL, can offer a short-acting benzodiazepine.
Should never be used in severe liver impairement
Benzodiazepine side effects
As a CNS depressant it causes:
- drowsiness
- reduced alertness
- confusion
- Ataxia (affects coordination, balance, speech)
- Muscle weakness
- May also have a paradoxical effect: increasing anxiety, hostility and aggression
- Must avoid alcohol as it is also a CNS depressant
Benzodiazepine side effects
- Respiratory depression
This effect is enhanced if co-prescribed with opioid, can be fatal.
Patients must report signs and symptoms of slow breathing, sedation, blueish lips and skin
Patients taking methadone must be monitored for ~ 2 weeks
- Dependence and tolerance
Must be gradually withdawn to prevent benzodiazepine withdrawal syndrome
Increased risk with shorter-acting benzodiazepines
Benzodiazepine interactions
Interacts with other CNS depressants:
alcohol, opioids, antihistamines, antipsychotics, barbiturates, Z drugs
Attention deficit hyperactivity disorder
Symptoms:
Inattention: short attention spam, easily distracted
Hyperactive and Impulsiveness: unable to sit still, acting without thinking
ADHD treatment
First line: Methylphenidate OR lisdexamfetamine (or dexamfetamine if patient cannot tolerate long effect profile)
Alternative: Atomoxetine - non stimulant
Methylphenidate and amfetamines mechanism of action
stimulate CNS and increase dopamine levels in the brain
How is methylphenidate prescribed
Methylphenidate modified release preparations must be prescribed by brand.
Methylphenidate and amfetamines side effects
- growth restriction - can stunt growth so treatment breaks over school holidays can be had
- psychiatric disorders. Monitor psychiatric symptoms
- CVS effects, like tachycardia, increased BP. So contraindicated in CVD, severe hypertension, hyperthyroidism.
- insomnia
- tics and tourette’s syndrome (vocal and motor tics that last longer than a year)
- reduced apetite AND weight loss
Methylphenidate and amfetamines interactions
Methylphenidate and amfetamines are serotonergic drugs.
So increased serotonin syndrome with:
SSRI’s, TCA’s, MAOI’s, Lithium, MAO-B inhibitors, methadone, St John’s Wort, 5-HT1 agonists, 5-HT3 receptor antagonist e.g ondanestron
Serotonin drugs increases serotonin (5-HT) or act on serotonin 5-HT receptors
What is bipolar disorder
extreme mood swings varying from extremely happy to extremely sad, and can last for several weeks or months
Bipolar disorder symptoms
- Mania - high mood:
high energy
risky, harmful acts
overly ambitious acts
- Depression: low mood
Bipolar disorder treatment
For acute episodes and maintenance:
* Lithium
* Valproate
* 2nd generation Antipsychotic (olanzapine OR quetiapine, risperidone for acute episodes only)
Antidepressants should not be given in acute episodes, as they elevate moood and can worsen mania
Lithium prescribing
Patients must carry their alert card at all times
Patients must be maintained on the same brand, different brands have different bioavailabilities
Lithium and NSAIDS
Use of NSAIDs and lithium should be avoided together if possible. As NSAIDs reduce lithium excretion leading to lithium toxicity
Lithium therapeutic index and monitoring
0.4-1 mmol/L
treat patient and not level
Blood samples are taken 12 hours after dose. In the first year, blood levels are taken every 3 months and every 6 months thereafter, UNLESS the patient’s blood lithium has been affected.
Usually affected by sodium and water intake.
Lithium toxicity signs
G: gastro-intestinal effects, V+D
R: renal effects - polyuria and hypOnatraemia
E: eyes blurred vision
E: extrapyramidal symptoms, e.g tremor
N: nervous sytem, e.g confusion, drowsiness
Lithium is nephrotoxic and can cause nephrogenic diabetes insipidus where much water is lost
Lithium is renally cleared, HypOnatraemia, diuretics, intercurrent illness, diarrhoea, vomiting, predisposes to lithium toxicity due to loss of electrolytes.
High fluid intake dilutes blood sodium levels = psuedo hypOnatraemia
Low fluid intake predisposes to lithium toxicity
Lithium counselling
hyPERnatraemia can also cause lithium levels to fall so patients must maintain their salt and fluid inake
Lithium side effects
- Hypothryroidism: patients must report signs such as weight gain, cold intolerance
MONITOR: TFT - Nephrotoxicty: patients must report signs of polyuria, polydipsia
MONITOR: RFT - Prolong QT interval
MONITOR: cardiac function, ECG, - Benign intracranial hypertension
patient must report signs of: persistent headaches, visual disturbances - Lowers seizure threshold
caution: epilepsy
