Monoamine oxidase inhibitors

Question 1

What is monoamine?

Answer 1

A compound having a single amine group in it’s molecule, especially one that is a neurotransmitter i.e. dopamine or serotonin (5-HT).

Question 2

Examples of monoamine oxidase inhibitors?

Answer 2

Selegeline, moclobemide and phenelzide.

Question 3

Indications for medication?

Answer 3

Depressive illness (rarely used)

Question 4

Mechanism of action for monoamine oxidase inhibitors?

Answer 4

Irreversibile (phenelzide) or reversible (moclobemide) inhibitors of MAO-A and B.

Question 5

Contraindications and cautions for monoamine oxidase inhibitors?

Answer 5

• Contraindicated in pregnancy (increased risk of neonatal malformation) and manic phase of bipolar disorder.
• Use with great caution in elderly.

Question 6

Adverse effects of monamine oxidase inhibitors?

Answer 6

• “Cheese reaction” - hypertensive crisis caused by inhibition of MAO - A in gut (and liver) by irreversible inhibitors. On consumption of cheese, patient can develop acute attack of hypertension.
• Can increase effects of other drugs (e.g barbiturates)
• Insomnia
• Postural hypotension
• Peripheral oedema

Question 7

Administration route of medication?

Answer 7

PO (orally)

Question 8

What is the “cheese” reaction in monoamine oxidase inhibitors?

Answer 8

An acute attack of hypertension that can occur in a person taking a monoamine oxidase inhibitor (MAOI) drug who eats cheese, caused by an interaction of the MAOI with tyramine