DEPRESSION: MAOIs

Question 1

MoA

Answer 1

Blocks monoamine oxidase enzymes, which leads to an accumulation of monoamines:
- DA
- NA
- 5HT

Question 2

When are they used?

Answer 2

Rarely used due to significant food/drug interactions.

Question 3

Irreversible MAO-A & MAO-B inhibitors

Answer 3

Phenelzine (hepatotoxicity more likely)
Isocarboxazid (hepatotoxicity more likely)
Tranylcypromine (greatest stimulant action)

Question 4

Reversible MAO-A inhibitors

Answer 4

Moclobemide
- No washout period
- Short acting

Question 5

for tranylcypromine, it is given BD, but second dose should be taken at a time no later than…

Answer 5

3pm

Question 6

Contraindications

Answer 6

• Cerebrovascular disease
• Not indicated in manic phase
• Severe cardiovascular disease
• phaeochromocytoma
• Avoid in hepatic impairment

Question 7

Side effects

Answer 7

Hepatotoxicity
Postural hypotension/hypertensive responses
Hypertensive crises (tranylcypromine)

Question 8

Hepatotoxicity

Answer 8

More likely with phenelzine and isocarboxazid

Question 9

Postural hypotension/hypertensive responses

Answer 9

Discontinue if palpitations or frequent headaches occur

Question 10

Hypertensive crises (tranylcypromine)

Answer 10

Discontinue if hypertensive crises with throbbing headaches.
More likely with tranylcypromine - most stimulant action

Question 11

Patient counselling

Answer 11

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

Question 12

What food must be avoided in patients taking MAOIs and why

Answer 12

• 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

Question 13

Tyramine rich food

Answer 13

• 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

Question 14

Dopa-rich food

Answer 14

broad bean pods

Question 15

How long after stopping MAOIs must you avoid tyramine-rich or dopa-rich food

Answer 15

Avoid tyramine-rich or dopa-rich food or drinks with, or for 2 to 3 weeks after stopping, the MAOI.

Question 16

Interactions - hypertensive crises

Answer 16

Sympathomimetics
- Pseudoephedrine
- Adrenaline
- Noradrenaline

Dopaminergic drugs
- Levodopa
- DRAs
- MAOB inhibitors

TCAs (potentially lethal)
ESPECIALLY
- Tranylcypromine
- Clomipramine

Question 17

How long to start other AD after treatment with MAOIs has been stopped.

Answer 17

do not start for 2 weeks after treatment has been stopped
3 weeks if starting clomipramine or imipramine

Question 18

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

Answer 18

Need to wait 3 weeks (if going onto imipramine or clomipramine from MAOI, otherwise normally wait 2 weeks)

Question 19

A patient is taking tranylcypromine but have not had response. They are going to be switched onto phenelzine. When can they start taking phenelzine?

Answer 19

An MAOI should not be started until at least 2 weeks after a previous MAOI has been stopped (then start at reduced dose)

Question 20

An MAOI should not be started until at least ….. days after a TCA has been stopped

Answer 20

7-14 days
3 weeks for clompiramine, imipramine

Question 21

An MAOI should not be started until at least ……. after an SSRI has been stopped

Answer 21

A week
5 weeks in the case of fluoxetine

Question 22

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?

Answer 22

5 weeks

Question 23

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.

Answer 23

Fluanxol (flupentixol)

Question 24

True or false - pt taking irreversible MAOIs should avoid antihistamines (even non drowsy)

Answer 24

Yes, avoid as increased antimuscarinic adverse effects

Question 25

avoid these 3 drugs with irreversible MAOIs because they are predicted to increase risk of elevated BP when given when them.

Answer 25

buspirone, entacapone, opicapone

Question 26

A patient is suffering from pain that paracetamol and NSAIDs have not controlled. You are looking to optimise their pain by adding an opioid, but quickly realise this is contraindicated because they are taking a certain type of AD. Opioids are predicted to increase risk of CNS excitation or depression when given with these type of ADs, so avoid. which AD?

Answer 26

MAOIs