Depression - Pharmacology Flashcards
Which drugs are usually first line in depression?
SSRIs
How long do anti-depressants usually take to work?
2-6 weeks
If you need a quicker response than what anti-depressants can offer, what treatment can be used?
ECT
How should anti-depressants be started and why?
Started at a low dose and titrated up, to avoid initiation side effects
In psychotic depression an anti-depressant and anti-psychotic can be combined. Which should be the long-term mainstay of treatment?
Anti-depressant
What should you do when prescribing anti-depressants in older people?
Lower the dose - usually half of the adult dose to start with
Why should you be cautious prescribing anti-depressants in younger patients?
They can sometimes cause agitation which leads to suicidal behaviour in young people
What defines non-response to an anti-depressant?
No or inadequate response after 6 weeks at the maximum or highest tolerated dose
Why is it important to check the BNF before changing anti-depressants?
Some drugs require a wash out period
What dose of anti-depressant should patients be continued on once there has been an effect?
The same dose! (the dose that gets you well keeps you well)
After a first depressive episode, how long should treatment with an anti-depressant be continued for?
6-12 months after full resolution of symptoms
After a second depressive episode, how long should treatment with an anti-depressant be continued for?
12-24 months after full resolution of symptoms
After a third depressive episode, how long should treatment with an anti-depressant be continued for?
Indefinitely (if the patient is willing)
When may anti-depressants be continued indefinitely after just one episode?
If the depression has been very severe
How should an anti-depressant be stopped?
By tapering the dose - never stop suddenly
When can an anti-psychotic be used in depression?
It can be combined with an anti-depressant in psychotic unipolar depression, and can also be used as an adjunct to an anti-depressant even if there are no psychotic symptoms
What tests should be checked before starting an atypical anti-psychotic and at 1 month?
BP, weight, lipids, blood glucose, ECG, FBC, Us and Es and LFTs.
After 1 months use of an anti-psychotic, how often should all the relevant tests be performed?
At least yearly, possibly more often depending on the results and other risk factors
In mood disorders, which type of anti-psychotic is more likely to be used?
Atypical
Why can foods containing tyramine not be consumed if on an MAOI?
Tyramine is a potent releaser of noradrenaline, and MAOIs inhibit the breakdown of noradrenaline. This can lead to a hypertensive crisis.
What are some signs which may signal a hypertensive crisis in a patient on an MAOI?
Headache, dyspnoea, nosebleeds, anxiety
What can a hypertensive crisis lead to in a patient on an MAOI?
Arrhythmias, stroke, seizures and death
How is a hypertensive crisis treated?
An infusion of phentolamine
What is an example of an irreversible MAOI?
Phenelzine
What is an example of a reversible MAOI?
Moclobemide
What is the advantage and disadvantage of a reversible MAOI compared to an irreversible one?
Less side effects, but less effective
What is the mechanism of action of MAOIs?
They work by irreversibly or reversibly blocking the monoamine oxidase enzyme to stop the metabolism of monoamine neurotransmitters. This means that the post-synaptic concentration of neurotransmitter is increased and hence the action of the neurotransmitter lasts longer.
The action of which neurotransmitters are increased by MAOIs?
Noradrenaline, dopmine and 5-HT
What are the indications for the use of MAOIs?
Only used in severe, treatment resistant depression
Why are MAOIs not used regularly?
Because of side effects and dietary restrictions, and many other drug interactions
What are the commoner side effects of MAOIs?
Postural hypotension, drowsiness, insomnia, nausea, constipation
What are some rare side effects of MAOIs?
Hypertensive crisis, hepatic impairment, seizures
What other medication should not be taken alongside MAOIs?
Nasal decongestants
What are the dietary requirements when taking MAOIs?
Cheese, wine, yeast products and anything else which is fermented