DEPRESSION: MAOIs Flashcards
(26 cards)
MoA
Blocks monoamine oxidase enzymes, which leads to an accumulation of monoamines:
- DA
- NA
- 5HT
When are they used?
Rarely used due to significant food/drug interactions.
Irreversible MAO-A & MAO-B inhibitors
Phenelzine (hepatotoxicity more likely)
Isocarboxazid (hepatotoxicity more likely)
Tranylcypromine (greatest stimulant action)
Reversible MAO-A inhibitors
Moclobemide
- No washout period
- Short acting
for tranylcypromine, it is given BD, but second dose should be taken at a time no later than…
3pm
Contraindications
- Cerebrovascular disease
- Not indicated in manic phase
- Severe cardiovascular disease
- phaeochromocytoma
- Avoid in hepatic impairment
Side effects
Hepatotoxicity
Postural hypotension/hypertensive responses
Hypertensive crises (tranylcypromine)
Hepatotoxicity
More likely with phenelzine and isocarboxazid
Postural hypotension/hypertensive responses
Discontinue if palpitations or frequent headaches occur
Hypertensive crises (tranylcypromine)
Discontinue if hypertensive crises with throbbing headaches.
More likely with tranylcypromine - most stimulant action
Patient counselling
Avoid foods containing tyramine
Fresh food only - avoid stale/going off food.
Avoid alcohol/low alcohol drinks.
Dangers of food/drug interactions exist two weeks after stopping an irreversible MAOI
What food must be avoided in patients taking MAOIs and why
- Avoid Tyramine rich foods (e.g. Mature cheese, Marmite)
- Avoid alcohol and low alcohol content drinks
- Avoid foods that are stale or going off (especially for meat, fish, or poultry)
If they don’t avoid these, then there is a risk of hypertensive crisis
Tyramine rich food
- mature cheese
- salami
- pickled herring
- Bovril®, Oxo®, Marmite®
- or any similar meat or yeast extract
- or fermented soya bean extract
- some beers, lagers or wines
Dopa-rich food
broad bean pods
How long after stopping MAOIs must you avoid tyramine-rich or dopa-rich food
Avoid tyramine-rich or dopa-rich food or drinks with, or for 2 to 3 weeks after stopping, the MAOI.
Interactions - hypertensive crises
Sympathomimetics
- Pseudoephedrine
- Adrenaline
- Noradrenaline
Dopaminergic drugs
- Levodopa
- DRAs
- MAOB inhibitors
TCAs (potentially lethal)
ESPECIALLY
- Tranylcypromine
- Clomipramine
How long to start other AD after treatment with MAOIs has been stopped.
do not start for 2 weeks after treatment has been stopped
3 weeks if starting clomipramine or imipramine
A patient is to be commenced on imipramine. They were previously on isocarboxazid. How long to wait until they can start taking imipramine?
1 day
1 week
2 weeks
3 weeks
4 weeks
No need to wait
Need to wait 3 weeks (if going onto imipramine or clomipramine from MAOI, otherwise normally wait 2 weeks)
A patient is taking tranylcypromine but have not had response. They are going to be switched onto phenelzine. When can they start taking phenelzine?
An MAOI should not be started until at least 2 weeks after a previous MAOI has been stopped (then start at reduced dose)
An MAOI should not be started until at least ….. days after a TCA has been stopped
7-14 days
3 weeks for clompiramine, imipramine
An MAOI should not be started until at least ……. after an SSRI has been stopped
A week
5 weeks in the case of fluoxetine
A patient has just stopped taking fluoxetine and is going to be switched to phenelzine, an MAOI. How long do they have to wait to be switched onto this after stopping?
5 weeks
Not MAOI - this drug has antidepressant properties when given by mouth in low doses. It is also used for the treatment of psychoses. It is a thioxanthene.
Fluanxol (flupentixol)
True or false - pt taking irreversible MAOIs should avoid antihistamines (even non drowsy)
Yes, avoid as increased antimuscarinic adverse effects
