Mental Health Drugs Flashcards
(38 cards)
Name 2 tricyclic antidepressants?
- Amitriptyline
2. Lofepramine
What is the indication for use of tricyclic antidepressants? (2)
- Moderate to severe depression: as second-line treatment, where firstling SSRIs are ineffective
- Neuropathic pain (although they are not licensed for this indication)
What is the mechanism of action of tricyclic antidepressants?
Tricyclic antidepressants inhibit neuronal repute of serotonin (5-HT) and noradrenaline from the synaptic cleft, thereby increasing their availability for neurotransmission. This appears to be the mechanism by which they improve mood and physical symptoms in moderate-to-severe depression and probably accounts for their effect in modifying neuropathic pain.
They also block a wide array of receptors, including muscarinic, histamine, (H1), alpha-adrenergic (alpha 1 and 2) and dopamine (D2) receptors. This accounts for the extensive adverse effects profile that limits their clinical utility.
What are the side effects caused by the tricyclic antidepressants blocking the anti-muscarinic receptors? (4)
Blockade of anti-muscarinic receptors causes:
- Dry mouth
- Constipation
- Urinary retention
- Blurred vision
What are the side effects caused by tricyclic antidepressants blocking histamine and alpha receptors? (4)
- Sedation
- Hypotension
- Arrhythmias / ECG changes
- Convulsions / hallucinations / mania
What are the side effects caused by tricyclic antidepressants blocking dopamine receptors? (3)
- Breast changes?!
- Sexual dysfunction
- Extrapyramidal symptoms - tremor/dyskinesia
What complications occur if an overdose of tricyclic antidepressants is taken? (5)
- Severe hypotension
- Arrhythmias
- Convulsions
- Respiratory failure
- Coma
…can be fatal
What are the side effect of sudden withdrawal of tricyclic antidepressants? (4)
- GI upset
- Neurological
- Influenza-like symptoms
- Sleep disturbance
When should tricyclic antidepressants be prescribed with caution?
1. In the elderly In people with: 2. CVD 3. Epilepsy 4. Constipation 5. Prostatic hypertrophy 6. Raised intra-ocular pressure
Which drug type should tricyclic antidepressants not be prescribed alongside and why?
Monoamine oxidase inhibitors - both drug classes increase serotonin and noradrenaline levels as the synapse and together they can precipitate hypertension and hyperthermia or serotonin syndrome.
Name 4 types of selective serotonin re-uptake inhibitors?
- Citalopram
- Fluoxetine
- Sertraline
- Escitalopram
What are the indications for use of SSRIs? (3)
- Moderate to severe depression: as a first-line treatment, and in mild depression if psychological treatments fail.
- Panic disorder
- Obsessive compulsive disorder
What is the mechanism of action of SSRIs?
SSRIs preferentially inhibit neuronal repute of serotonin (5-HT) from the synaptic cleft, thereby increasing its availability for neurotransmission. This appears to be the mechanism by which SSRIs improve mood and physical symptoms in depression and relieve symptoms of panic and obsessive disorders.
How does the mechanism of action for SSRIs differ to that of tricyclic antidepressants?
SSRIs do not inhibit noradrenaline uptake and cause less blockade of other receptors.
Which drug class, SSRIs or tricyclic antidepressants, is preferred in the treatment of depression, and why?
SSRIs are generally preferred, as although the efficacy of the two drug classes in the treatment of depression is similar, SSRIs have fewer adverse effects and are less dangerous in overdose.
What are the side effects associated with SSRI use? (7)
- GI upset
- Appetite and weight disturbance (loss or gain)
- Hypersensitivity reactions - skin rash
- Hyponatraemia - present with confusion
- Suicidal thoughts and behaviour
- Lower seizure threshold
- Increase risk of bleeding
If an overdose of an SSRI is taken, or if SSRIs are taken in combination with another antidepressant, what are the possible side effects?
Serotonin syndrome - this is triad of autonomic hyperactivity, altered mental state and neuromuscular excitation.
When should SSRIs be prescribed with caution?
In people who are at particular risk of adverse effects, so people with:
- Epilepsy
- Peptic ulcer disease
- In young people
- Hepatic impairment (as SSRIs are metabolised by the liver)
What class of drug are SSRIs not to be prescribed alongside?
Monoamine oxidase inhibitors
Which SSRIs have fewer interactions, so should be the preferred choice when prescribing for patients who have multiple comorbidities?
- Citalopram
2. Escitalopram
If patients are taking SSRIs alongside NSAIDS/aspirin, what else needs to be prescribed and why?
Gastroprotection should be prescribed due to an increased risk of GI bleeding.
Name 5 benzodiazepines?
- Lorazepam
- Temazepam
- Diazepam
- Chlordiazepoxide
- Midazolam
What are the 5 indications for use of benzodiazepines?
- Seizures and status epilepticus: first-line management
- Alcohol withdrawal reactions: first-line management
- Sedation for interventional procedures: if general anaesthesia is unnecessary or undesirable
- Anxiety: for short-term treatment if anxiety is severe, disabling or distressing
- Insomnia: for short-term treatment, if severe, disabling or distressing.
What is the mechanism of action of benzodiazepines?
The target of benzodiazepines is the gamma-aminobutyric acid type A (GABAa) receptor. The GABAa receptor is a chloride channel that opens in response to binding by GABA, the main inhibitory neurotransmitter in the brain. Opening the channel allows chloride to flow into the cell, making the cell more resistant to depolarisation.
Benzodiazepines facilitate and enhance binding of GABA to the GABAa receptor. This has a widespread depressant effect on synaptic transmission.
The clinical manifestations of this include reduced anxiety, sleepiness, sedation and anti convulsive effects.
