Drugs Used in Psychiatric Disease Flashcards
How is depression diagnosed in terms of symptoms?
2 of 3 core symptoms needed:
Low mood
Anhedonia
Decreased energy
Secondary symptoms: Decreased appetite Sleep disturbance Hopelessness (depressive cognitions) Reduced concentration Irritability Self harm or suicidal ideas or acts Reduced libido Can have psychotic symptoms
What are the different classes of antidepressants?
Monoamine oxidase inhibitors
Monoamine uptake inhibitors
- Non selective
- Selective
Tell me about selective serotonin reuptake inhibitors.
SSRIs
Fluoxetine, citalopram, paroxetine, sertraline
Almost completely absorbed
long half life
What are some of the ADRs of SSRIs?
Common
Anorexia
Nausea
Diarrhoea
Rare
Precipitation of mania
Possible increased ideation
Neurological side effects (tremor, extrapyramidal syndromes)
(Reasonably safe in overdose if taken on own)
Tell me about tricyclic antidepressants.
Imipramine, lofepramine, amitriptyline
Not used as often, not first line
Has a few actions:
Inhibition of noradrenaline uptake
Muscarinic cholinoceptor blockade - reduced cholinergic neurotransmission
Alpha 1-adrenoceptor blockade - suppression of noradrenergic neurotransmission
Lipid soluble
Absorbed from gut
Long half lives
What are some of the ADRs of TCAs?
CNS
Sedation
impairment of psychomotor performance
Lowering of seizure threshold
Autonomic nervous sytem
Reduction in glandular secretions
Eye accommodation block
CVS
Tachycardia
Postural hypotension
Impair myocardial contractility
GI
Constipation
Extremely toxic in overdose
Tell me about ‘pure’ non-selective monoamine uptake inhibitors (SNRIs).
Venlafaxine (duloxetine)
Serotonin - Noradrenaline reuptake inhibitors
Second/third line drugs
Dose dependant - lower doses serotonin action, higher doses noradrenaline
Relatively short half-life
What are some of the ADRs of SNRIs
Same as SSRIs
Anorexia, nausea, diarrhoea
Precipitation of mania, increased suicidal ideation and tremors
ALSO has other ADRs:
sleep disturbances, increased BP, dry mouth, hyponatraemia
What are the symptoms of paranoid schizophrenia?
Disturbances of thinking Hallucinations Delusions Unusual speech-thought disorder Behavioural changes Lack of insight Negative symptoms
What are the different theories of schizophrenia?
Dopamine hypothesis
- Dopamine hyperfunction
Increased 5-HT function??
Glutamate hypofunction
What are the general actions of all antipsychotics?
Sedation (within hours) Tranquilisation (within hours) Antipsychotic (several days or weeks) Negative symptoms (weeks) Production of extrapyramidal side effects (hours or days)
What are the advantages of atypical antipsychotics?
Less EPSE side effects therefore more acceptable to patient
Different preparations
Some once daily dosage
Differing side effect profiles can be matched o patient characteristics
First line treatment in schizophrenia
What are some of the ADRs of atypical antipsychotics?
Vary between drugs Can have extrapyramidal side effects at high doses Weight gain -e.g. olanzapine Increased prolactin e.g. risperidone Sedation
Tell me about typical antipsychotics.
Haloperidol safe in emergencies Chloromazine More sedating Well known side effects Wide range of pharmacological action: Dopamine blockade Anticholinergic Alpha adrenergic blockade Antihistamine effect
Name some atypical antipsychotics.
Olanzapine
Risperidone
Clozapine
Quetiapine
What are some of the ADRs typical antipsychotics/
Extrapyramidal side-effects Parkinsonism Acute dystonia Akathasia Tardive dyskinesia
Neuroleptic malignant syndrome Severe rigidity Hyperthermia Increased CPK Autonomic liability
Postural hypotension
Weight gain
Endocrine changes (prolactinaemia)
Pigmentation
What are some of the toxicities of atypical antipsychotics?
Central nervous system depression
Cardiac toxicity
Risk of sudden death with high dose
What are some of the characteristics of anxiety disorders?
Fear out of proportion to situation Avoidance Fear of dying, going crazy Physical symptoms - Light headedness - Shortness of breath - Hot and cold flushes - Nausea - Palpitations - Numbness - Pins and needles
What are the overall treatments for anxiety?
Non pharmacological approaches first line
- CBT
Treat any coexistent disorder
Drugs - antidepressants, anxiolytics, occasionally antipsychotics
What are the principle neurotransmitter systems involved in anxiety disorders?
Gamma-aminobutyric acid - GABA
Serotonin (5-HT)
Noradrenaline
Tell me about benzodiazepines and their use in anxiety disorders.
Anxiolytics
Diazepam, Lorazepam
Exerts effects through structure known as GABA-BDZ receptor complex
Benzodiazepines only bind to BDZ receptor of which there are 2 main groups - high and low affinity
High affinity group - Important in anxiolytic, hypnotic and anticonvulsant effects of BDZs
Inhibitory effects in brain
BDZs act as full agonists at these receptor sites
Lead to enhancement of GABA
Highly lipid soluble
Long half-life
Tell me about tolerance and dependence of benzodiazepines.
Tolerance can occur
i.e. need to increase the dose to achieve the same effect
Dependence - on discontinuation of treatment can get withdrawal effects
e.g. insomnia, agitation, anxiety
What are the ADRs of benzodiazepines?
Common
Drowsiness
Psychomotor impairment
Occasional Dry mouth Blurred vision Gastrointestinal upset Ataxia Headache Reduced blood pressure
Rare
Amnesia
Restlessness
Rash
What are the possible toxicities of benzodiazepines?
Cleft lip and palate if used in pregnancy??
If taken late in pregnancy may7 cause respiratory depression and feeding difficulties in babies
