Revision - Psych Drugs Flashcards
When would typical antipsychotics be indicated over atypical in the management of schizophrenia?
Particularly when the METABOLIC side effects of second generation (atypical) antipsychotics are likely to be problematic
Give 3 contraindications for 1st line antipsychotics
1) Elderly
2) Dementia
3) Parkinson’s
What are elderly patients on typical antipsychotics at a particularly increased risk of?
Stroke & VTE
What is an alternative to typical antipsychotics for Parkinson’s patients?
Small dose of lorazepam might be alternative in distress
Management of akathisia?
Propranolol
What is NMS?
A life-threatening idiosyncratic reaction to (often 1st line) antipsychotic drugs (rare).
Can happen after change in dose, treatment commencing or suddenly stopping
What happens in NMS?
Ridigity –> muscle breakdown –> rhabomyolysis –> kidney failure
Give some symptoms seen in NMS
Fever
Altered mental status
Autonomic dysfunction
Neuromuscular excitability –> hypertonia, hyperreflexia
Confusion
Autonomic dysregulation –> tachycardia, hyperthermia, unstable BP
Management for NMS?
1) Stop antipsychotic
2) IV fluids
3) Sodium bicarbonate
4) Codeine
5) Dantrolene (muscle relaxant)
6) Bromocriptine (dopamine agonist)
Management of tardive dyskinesia?
Tetrabenazine
Which 1st line antipsychotics particularly causes QT interval prolongation?
Haloperidol
In an emergency, what 1st line antipsychotic is typically given?
Haloperidol can be given via rapid acting IM injection
What investigations are required 3 MONTHS after starting 1st line antipsychotics?
Weight
Lipids
Then annually.
What investigations are required 6 MONTHS after starting 1st line antipsychotics?
Fasting blood glucose.
Then annually.
Which 2nd line (atypical) antipsychotic is associated with weight gain and hypercholesterolaemia?
Olanzapine
Which 2nd line (atypical) antipsychotic is LEAST likely to help with SLEEP?
Risperidone
Which 2nd line (atypical) antipsychotic has the MOST TOLERABLE side effect profile, particularly for prolactin elevation?
Aripiprazole
Which class of antipsychotics should be used in schizophrenia where NEGATIVE symptoms are prominent?
Atypical
What are 2 major contraindications of clozapine?
1) severe heart disease
2) history of neutropenia
Give some drug interactions for 2nd line antipsychotics
1) dopamine blocking antiemetics e.g. metoclopramide
2) drugs which prolong the QT interval
3) sedating drugs
Why can carbamazepine (anti-epileptic) not be prescribed with clozapine?
Both affect bone marrow function
Symptoms of agranulocytosis?
o Myocarditis
o Weight gain
o Excessive salivation – sleep sitting up/towels
o Seizures
How does lithium affect calcium levels?
Often mild hypercalcaemia seen (due to hyperparathyroidism)
What is dysarthria?
Difficulty speaking because the muscles you use for speech are weak.
Why is lithium contraindicated in Cardiac disease or Addison’s disease?
Causes sodium depletion
Which SSRI is licensed in bulimia nervosa?
Fluoxetine
Which SSRI causes QT prolongation?
Citalopram
Why should SSRIs NOT be given with monoamine oxidase inhibitors?
both increase synaptic serotonin levels so together may precipitate serotonin syndrome
Give 4 classes of drugs that SSRIs should not be prescribed with/prescribed with caution with?
1) MAOIs, triptans & tramadol –> risk of serotonin syndrome
2) Aspirin or NSAIDs –> risk of GI adverse effects
3) Anticoagulants –> risk of bleeding
4) Drugs that prolong QT interval e.g. antipsychotics
How long should SSRI treatment be continued for after the patient feels better?
6m
How should patients stop SSRIs?
Gradual dose reduction over 4 weeks
What class of drug are amitriptyline, clomipramine & imipramine?
TCAs
Which TCA is licensed for OCD?
Clomipramine
Cardiac effect of TCAs antidepressants blocking a1 receptor?
Inhibit smooth muscle contraction –> hypotension
What is the side effect caused by tricyclic antidepressants blockage of H1 receptors?
Sedation & weight gain
What is the side effect caused by tricyclic antidepressants blockage of a1 receptors?
Hypotension
What are the side effects caused by tricyclic antidepressants blockage of dopamine receptors? Why?
o Breast changes –> due to raised prolactin levels
o Sexual dysfunction –> due to raised prolactin levels
o EPSEs (tremors, dyskinesia) –> thought to create a dopaminergic-cholinergic imbalance that leads to development of extrapyramidal symptoms
Anticholinergics and IOP?
Can increase IOP –> avoid in raised IOP e.g. glaucoma
Why should TCAs be used with CAUTION in people with prostatic hypertrophy and/or raised intraocular pressure?
May be worsened by antimuscarinic effects
Give 3 examples of monoamine oxidase inhibitors (MAOIs)
1) Phenelzine
2) Isocarboxazid
3) Moclobemide
MOA of MAOIs?
Inhibit the enzyme monoamine oxidase –> prevent the breakdown of amine
neurotransmitters:
- 5-HT (serotonin)
- Dopamine
- Noradrenaline
How can MOAIs interact with food?
‘Tyramine’ reaction
If you take an MAOI and you eat high-tyramine foods, tyramine can quickly reach dangerous levels.
This can cause hypertensive crisis.
What class of drug is Mirtazapine?
NaSSa
Name 2 SNRIs
1) Venlafaxine
2) Duloxetine
How does venlafaxine affect the QT interval?
Prolongs it –> fainting, seizures
Why is the efficacy of antiepileptic drugs reduced by antipsychotics?
As antipsychotics lower the seizure threshold
What is the interaction between carbamazepine and antipsychotics?
Carbamazepine DECREASES plasma concentrations of antipsychotics
(is an enzyme inducer)
What condition are benzos contraindicated in?
Mysathenia gravis
Contraindications of AChEIs?
1) Use with caution in asthma and COPD (due to increased secretions), and those at risk of developing peptic ulcers
2) Avoid in patients with heart block or sick sinus syndrome, or bradycardia
What MMSE score indicates severe dementia?
<10
Why should AChEIs be used with caution alongside NSAIDs and corticosteroids?
Concomitant therapy with NSAIDs and corticosteroids may increase risk of peptic ulceration
How long should z drugs be prescribed for?
Max 4 weeks
What class of drug is used in the management of NMS?
Dopamine agonist - bromocriptine
Why are SSRIs contraindicated in epilepsy?
Cause hyponatraemia (can lead to seizures)
