Therapeutics Flashcards
What is ECT ?
Electroconvulsive therapy is a treatment for severe depression where a small dose of electric current is used to induce seizures
What is the regimen of ECT ?
Administered twice weekly for up to 12 treatments
What type of pulse is given for optimal results in ECT ?
Brief pulse
What are the indications for ECT ?
Depression
Mania
Catatonia
What are some contra-indications for ECT ?
Raised intra-cranial pressure, cerebral aneurysm, recent cerebrovascular event
MI within 3 months
Unstable angina
DVT
Acute resp distress
Cochlear implant
Pregnancy
Uncontrolled epilepsy
What are some side effects of ECT ?
Confusion
Headache
Status epilepticus
Stroke
Bleeding from ulcers
Broken teeth
Memory loss
What are some side effects from the anaesthesia used in ECT ?
MI
Arrhythmia
Aspiration pneumonia
Nausea
Malignant hyperthermia
What are the physiological changes that occur from ECT ?
EEG changes
Cerebral blood flow increases
Blood brain barrier may be breached
Hormonal changes - TSH, ACTH, growth hormone and prolactin
What is needed for consent for ECT in someone lacks capacity ?
Second opinion approved doctor and complete T6
If emergency complete a C6
What monitoring is needed for ECT ?
Pre ECT physical health check
Consent
Medication
Monitoring side effects
Hamilton depression rating scale
What are some common adrenergic / noradrenergic receptor effects ?
Sweating
Tremor
Headaches
Nausea
Dizziness
What are some common Muscarinic receptor effects ?
Dry mouth , difficulty swallowing, thirst
Difficulty urinating
Urinary retention
Hot and flushed skin
Dry skin
How do most antidepressants work ?
Work on serotonin activity and the aim is to increase activity at post synaptic receptors
How long do most antidepressants take to work ?
2 - 3 weeks
How do SSRI’s work ?
Increase serotonin activity by reducing the presynaptic reuptake of serotonin after release. Therefore more serotonin sits in the synapse. This leads to a down regulation of post-synaptic receptors.
What are some common side effects of SSRI’s ?
Restlessness
Nausea
Headache
Weight changes
Sexual dysfunction
What are some examples of SSRI’s ?
Sertraline
Citalopram
Fluoxetine
Paroxetine
What are some risks for citalopram ?
Prolongs QTc
How do SNRI’s work ?
Act in the same way as SSRI’s nut bind to noradrenaline reuptake receptors as well
What are some side effects of SNRI’s ?
Sedation
Nausea
Sexual dysfunction
What are some SNRI’s ?
Duloxetine
Venlafaxine
When does venlafaxine need to started with caution ?
In heart disease - monitor BP at doses above 225mgs
What does mirtazapine act on ?
Acts as a 5HT-2 and 5HT-3 antagonist
Strong histamine 1 activity
What are the major side effects on mirtazapine ?
Sedation
Weight gain
What are some types of tricyclic antidepressants ?
Lofepramine
Nortiptyline
Amitriptyline
What are some side effects of tricyclic antidepressants ?
Muscarinic and histaminic side effects
Why do tricyclic antidepressants need close observation ?
Causes QTc prolongation and arrhythmias
What are MAOI’s ?
Monoamine oxidase inhibitors work on serotonin (A) or dopamine ( B ).
What is discontinuation syndrome ?
Antidepressants aren’t addictive but they can be difficult to stop as they cause sweating, shaking, agitation, insomnia.
Very unpleasant
Shorter the half life the bigger the problem
What are some signs and symptoms of serotonin syndrome ?
Headaches
Agitation
Hypomania
Shivering
Sweating
Hyperthermia
Tachycardia
Nausea
Hyper-reflexia
How do most antipsychotics work ?
Reduce level of dopamine activity at D2 receptors
Target dopaminergic pathways in the brain - mesocorticol and mesolimbic
What are some examples of typical antipsychotics ?
Haloperidol
Flupenthixol
Zuclopenthixol
What are some examples of atypical antipsychotics ?
Clozapine
Olanzapine
Risperidone
What are some side effects of antipsychotics ?
Sedation
Weight gain
QTc prolongation
Typical - bradykinesia, muscle stiffness, tremor, tardive dyskinesia, dizziness, sexual dysfunction
Atypical - weight gain, DM
What monitoring is required when starting antipsychotics ?
Baseline - FBC, lipids, HbA1c, weight ECG BP
Weekly - weight
3 monthly - FBC, lipids, LFT, HbA1c, ECG BP
What is neuroleptic malignant syndrome ?
Rare, life-threatening reaction to antipsychotics
What are some features of neuroleptic malignant syndrome ?
Fever
Confusion
Muscle rigidity
Sweating
Rhabdomyolysis
Renal failure
Seizures
What is the treatment for neuroleptic malignant syndrome ?
Emergency referral to ED
Stop antipsychotics
Give benzodiazepines
Fluid resus
Cooling blankets
O2 if necessary
Dantrolene to relax muscles
What does clozapine work on ?
D2 and 5HT-2 antagonist
What are some side effects of clozapine ?
Constipation - fatal bowel obstruction
Agranulocytosis
Hypersalivation
Urinary incontinence
What are some examples of anxiolytics ?
Beta blockers
Benzodiazepines
Pregabalin
Antidepressants
How do beta blockers reduce anxiety ?
They act by reducing autonomic nervous system activation
Bio-psycho-feedback
When are beta blockers contra-indicated ?
Asthma
How do benzodiazepines reduce anxiety ?
They bind to GABA receptors and potentate the effect of GABA and therefore reduce the excitability of neurones.
They are positive allosteric modulators of GABA receptor
What are some risks of benzodiazepines ?
Tolerance
Dependence
Misuse
Paradoxical disinhibition
How does pregabalin reduce anxiety ?
Binds to voltage gated calcium channels of neurones and reduces neuronal activity
What are some side effects of pregabalin ?
Sedation
Weight gain
What are some examples of hypnotics ?
Benzodiazepines - temazepam
Nonbenzodiazepines - zopiclone and zolpidem
What are some risks of prescribing hypnotics ?
Misuse
Dependence
Rebound insomnia
What are some examples of mood stabilisers ?
Lithium
Anticonvulsants
Second generation antipsychotics
How does lithium work ?
Mechanism of action is unknown
Lowers noradrenaline release and increases serotonin synthesis
What are some side effects of lithium ?
GI disturbance
Metallic taste
Dry mouth
Fine tremor
Polydipsia and polyuria
Weight gain
What are some long term effects of lithium ?
Hypothyroidism - usually reversible
Renal impairment - usually irreversible
What can lithium toxicity cause ?
Can be fatal
Confusion
Coarse tremor
Nausea and vomiting
Ataxia and seizures
What treatment is given for lithium toxicity ?
Stop lithium
IV fluids
Dialysis
Benzodiazepines for seizures
What are some medications that interact with lithium causing increasing levels ?
NSAIDs
Loop diuretics
ACEi
What second generation antipsychotic is used for bipolar ?
Quetiapine
What anticonvulsants can be used as mood stabilisers ?
Sodium valproate
Carbamazepine
Lamotrigine
What are some side effects of anticonvulsants as mood stabilisers ?
Sedation
Weight gain
Thrombocytopenia
What drugs are most commonly used in ADHD ?
CNS stimulants -
Methylphenidate
Dextroamphetamine
What is the mechanism of action of mirtazapine ?
Antidepressant that works by blocking alpha 2 adrenergic receptors which increases the release of neurotransmitters.
Why is mirtazapine used in the elderly ?
Two side effects - sedation and increased appetite - may help with insomnia and low weight
What is a risk of using MAOI’s ?
Have lots of side effects
- causes increased levels of tyramine which can result in a hypotensive crisis
What are some side effects of olanzapine ?
Metabolic syndrome - weight gain, hypertension, DM, hyperlipidaemia
Increased QRISK
Parkinsonism
Increased sedation
What are some risks of using risperidone ?
Increased prolactin release which causes
- galactorrhoea
- breast development
- amenorrhea
- low libido
- decrease in sperm production
- osteoporosis
What is beneficial about using risperidone ?
Less weight gain
Less sedation
What are the benefits from using aripiprazole ?
No weight gain
No sedation
No effect on the heart
Doesn’t affect prolactin
Restlessness
What is the mechanism of action of aripiprazole ?
Partial agonist of dopamine
What are the major risks of using clozapine ?
Agranulocytosis - risk of neutropenia sepsis
Cardiac Myositis
Constipation
Metabolic syndrome
What monitoring is needed when a patient is on clozapine ?
ECG
Blood tests
Required before medication is released to patient
What are some risks of using sodium valproate ?
Very teratogenic - can’t be given to women of child bearing age
Hepatotoxic
Weight gain
If sodium valproate has to be prescribed what must a woman of child bearing age be put on ?
Highly effective contraceptive - implant or copper coil
