Psychiatric Drugs Flashcards
Give some examples of typical antipsychotics
Haloperidol
Chloropromazide
Mechanism for typical antipsychotics
Antagonist dopamine D2 receptor
- Sedation occurs with hours
- Tranquillisation within hours
- Acts as an antipsychotic within weeks
Give some ADRs for typical antipsychotics
Extrapyramidal effects Anti-adrenergic effects - sedation and postural hypotension Anticholinergic effects Cardiac arrhythmias Weight gain, diabetes & metabolic syndrome Amennorhoea Galactorrhoea Hypothermia Neuroleptic malignant syndrome
Give the toxicities associates with typical antipsychotics
CNS depression
Cardiac toxicity
Sudden death with high dose - prolonged QT syndrome and torsades de points
Give some atypical antipsychotics
Olanzapine
Risperidone
Clozapine
Quetiapine
Give the mechanism for atypical antipsychotics
Antagonists 5HT receptors but also D2 receptors, but have a higher affinity for 5HT
- Sedation occurs with hours
- Tranquillisation within hours
Acts as an antipsychotic within weeks
Give some ADRs of atypical antipsychotics
Olanzapine = significant weight gain
Risperidone = increased prolactin
Sedation
Extrapyramidal side effects
Give some toxicities associated with atypical antipsychotics
Cardiac toxicity
Risk of sudden death - prolonged QT leading to torsades de points
What is the first line treatment for schizophrenia?
Atypical antipsychotics
- have better tolerated side effects
- less extrapyramidal side effects
What kind of treatment would you give to someone with an anxiety disorder?
Cognitive behavioural therapy
- save the medications for the severe cases of anxiety
What type of medication can be used to treat anxiety?
Antidepressants Benzodiazepines Antipsychotics Beta blockers Busiprone Barbituates
Mechanism for benzodiazepines
Enhance the action of GABA-A receptors
- positive allosteric modulation
- increase Cl current into the nerve, causing hyper polarisation, increasing AP threshold
ADRs for benzodiazepines
Sedation Withdrawal Tolerance (develops within weeks) Confusion, impaired coordination Aggression Seizures can be triggered with an abrupt withdrawal Respiratory and CNS depression
Give an antagonist for benzodiazepines
Flumazenil
- IV, can reverse overdose effects
Give some contraindications for benzodiazepines
Pregnancy - is teratogenic
Don’t use in someone with respiratory depression
Give some mood stabilisers
Lithium
Sodium valproate
Carbamezepine
Lamotrigine
Describe lithium
Administered as lithium carbonate
- mood stabiliser
- prophylaxis of mania and depression in bipolar disorder
- augments antidepressant action in unipolar depression
Give some theories as to how lithium works
- competes with Mg2+ and Ca2+
- increases 5HT levels
- antagonises effects of neurotransmitters without altering receptor density
Good for preventing relapse into mania
Lithium ADRs
Memory problems - learning new info Thirst Polyuria Tremor Drowsiness Weight gain Hair loss Rashes
Toxic effects of lithium
Coarse tremor Ataxia Dysarthria Reduced levels of consciousness Convulsions Coma Death
Give some characteristics of managing someone who is taking lithium
Good evidence that it reduces suicides
Need to monitor plasma levels as it has a narrow therapeutic window (0.5-1.0 mmol/L)
- need to check TFTs and U+Es
How would you treat lithium toxicity?
Supportive treatment
- Anticonvulsants
- IV fluids
- Haemodialysis
Give some drugs used to treat Alzheimer’s disease
Acetylcholinesterase inhibitors
NMDA antagonists
Give some examples of acetylcholinesterase inhibitors
Donepezil
Galantamine
Rivastigmine
Give some ADRs of acetylcholinesterase inhibitors
Nausea Vomiting Diarrhoea Fatigue Insomnia Headache Muscle cramps Bradycardia Syncope
What is the first line treatment for alzheimer’s?
Acetylcholinesterase inhibitors
Give an example of an NMDA antagonist
Memantine
Give some ADRs of NMDA antagonists
Hypertension Dyspnoea Headache Dizziness Drowsiness
What are extra-pyramidal side effects?
Parkinsonian side effects Akathisia Tardive dyskinesia - choreo-athetoid movements in tongue, lips and face Dystonia - muscle/muscle groups go into spasm
What is neuroleptic malignant syndrome?
Life-threatening reaction to medications which causes:
- Extreme EPSE
- Autonomic dysfunction
Complications include renal failure, pneumonia and thrombo-embolism.
Get increased creatine phosphokinase
What is the pathophysiology of neuroleptic malignant syndrome?
Decrease dopamine function due to:
- Dopamine blockade
- reduced function of D2 receptor
What is one of the side effects of clozapine?
Causes agranulocytosis and neutropenia
- Regular FBC monitoring is needed
- Drug should be discontinued if there are any concerns
Give the half lives for varying bezodiazepines
Diazepam = 20-100 hrs Lorazepam = 8-24 hrs Temazepam = 5-11 hrs Zopiclone = 4-6 hrs
What are the equivalent doses of lorazepam or temazepam to diazepam 10mg?
Lorazepam = 1mg Temazepam = 20mg
How do acetyl cholinesterase inhibitors work?
Increase the amount of acetylcholine in the synaptic cleft. This improves the brain function by improving the strength of nerve transmission.
When should you take caution in prescribing acetyl cholinesterase inhibitors?
COPD patients
Peptic ulcers
Hx of convulsions
What are central nervous system stimulants?
Act to improve concentration in children who have ADHD.
Give some examples of CNS stimulants
Methylphenidate
Dexamphetemine
Give some side effects of methylphenidate
GI disturbance Hypertension Tachycardia Palpitations Insomnia Nervousness
