Psychopharmacology Flashcards
What is the therapeutic window for lithium?
0.4-0.8 (or 1.0) mmol/L
What is there a marked increased risk of to the baby if lithium is taken during pregnancy?
Ebstein’s anomaly - a right ventricular outflow tract obstruction defect
How does lithium toxicity present? (4)
- Increased drowsiness
- Blurred vision
- GI upset - anorexia, vomiting
- Ataxia, coarse tremor
If lithium levels are >2mmol/l, what are the symptoms of severe toxicity? (4)
- Convulsions/hyperreflexia
- Renal failure
- Coma
- Death
What is the treatment of lithium toxicity?
- Hospitalise
- Stop lithium
- Check lithium levels
- Give fluids
5.
What are the alternatives to lithium? (other mood stabilisers)
- Sodium valproate
- Carbamazepine (auto induction?)
- Lamotrigine
What is the problem with switching to sodium valproate from lithium?
Hepato toxic
If a woman is planning to get pregnant/is pregnant, what is a safer drug to take rather than lithium for their bipolar disorder/depression resistant to treatment?
Antipsychotics - can function as mood stabilisers and are relatively safer in pregnancy -
1. Olanzepine
2. Haloperidol
(small dose and regular monitoring)
What is rapid tranquillisation?
- short term immediate treatment usually IM under restraint, due to highly agitated and aggressive behaviour
1. Protocol for controlling disturbed behaviour
2. Verbal methods should be tried first
3. Lorazepam 1mg +/- haloperidol 5mg (widely used, normally benzodiazepine is not enough, cannot give olanzapine and lorazepam together within an hour of each other)
A patient who was given IM rapid tranquillisation and who is on regular antipsychotics, experiences stiffness and slow movements, what is the cause of this?
Side effects of antipsychotic on the nigrostriatal pathway, blocking the dopamine receptors. It causes the parkinson-like side effects:
-Pseudo-parkinsonism
-Akathisia (inner restlessness)
-
How do you detect the side effects of antipsychotics?
Examine:
- Gait
- Tremor
- Restlessness
- test elbow rigidity
- finger/thumb tap test
Other side effects of antipsychotics in addition to parkinsonism?
Antimuscarinic - dry mouth, urinary retention
Antiadgrenergic
Antihistamine
What is neuroleptic malignant syndrome? (6)
Very rare (0.2%) and rapid onset of: 1. Stiffness 2. Impaired consciousness 3. Hyperpyrexia 4. Unstable blood pressure 5. CPK levels elevated 6. 10% mortality (immediately take a temperature to assess and send a blood test for creatinine kinase)
What do you need to consider if someone has treatment resistant schizophrenia?
- Compliance
- Co-morbidities - drugs?
- Correct diagnosis?
Which drug can be given for treatment resistant schizophrenia? (where they have tried two or more atypicals?)
Clozapine
What are the side effects of clozapine? (7)
- Agranulocytosis (1%)
- Blood tests (every week for the first 18 weeks)
- Drowsiness
- Constipation
- Hyper-salivation
- Hypotension
- Cardiomyopathy
Which two neurotransmitters is there a shortage of in depression?
Serotonin
Noradrenaline
What are the side effects of SSRIs? (8)
- Nausea
- Diarrhoea
- Sleep disturbance
- Anxiety
- GI bleeds
- Withdrawal effects
- Suicidality
- QTc? - SAD HART research
What are the side effects of TCAs?
- Block Ach muscarinic receptors - dry mouth, urinary retention
What foods must be avoided in someone taking MAOI? (6)
- Avocado
- Herring
- Meat extracts
- Cheese
- Beer
- Flavia beans
What can you do with treatment resistant depression?
- Check this is the correct diagnosis
- Exclude physical causes
- High enough dose, long enough time?
- Switch to new class e.g. SNRI/TCA/MAOIs
- Augment - lithium for a short time or antipsychotics
- ECT
Which medication is required for a patient suffering from severe side effects of his anti-psychotic. The side effects include repetitive involuntary side effects such as grimacing and sticking out the tongue.
Tetrabenazine - this patient is suffering from tardive dyskinesia and as the episode is described as severe, this is the most appropriate.
What drug is used to treat the side effect of akathisia (restlessness) as a result of anti-psychotics?
Propanolol
Which medication is used to treat acute dystonia, a side effect of anti-psychotics?
Procyclidine and benztropine
Which SNRI is most appropriate to prescribe for generalised anxiety disorder?
Venlafaxine
Which antidepressants are recommended during pregnancy? (3)
- Fluoxetine
- Amitriptyline
- Imipramine
Which antidepressants are recommended in breastfeeding? (2)
- Paroxetine
2. Sertraline
What is important to tell patients when starting them on antidepressants?
- Although they are not a solution to all the problems that may be co-existing/coinciding, they can lift your mood and give you a better chance of addressing them
- Antidepressants are effective in over 60% of patients, but it can be 10-20 days before you start to notice an effect, better sleep is often the first sign of improvement
- Antidepressants may have troublesome side effects, but these tend to resolve in the first mont of treatment
- Antidepressants should not be stopped suddenly once treatment is established
What is the response rate to SSRIs?
55-70%
What are the side effects of SSRIs? (7)
- Dry mouth
- Nausea
- Vomiting
- Diarrhoea
- Dizziness
- Agitation
- Sexual dysfunction