PARKINSON'S: MAOBi

Question 1

Monoamine-oxidase B inhibitors

Answer 1

o Seligiline
o Rasagiline
o Safinamide

Question 2

MoA

Answer 2

Inhibits monoamine oxidase B enzymes which breakdown monoamines e.g. dopamine

Question 3

When are they used?

Answer 3

Used alone in PD with motor symptoms that do not affect QoL
OR as an adjunct to Levodopa

Question 4

Side effects

Answer 4

• Alopecia (especially
  Selegiline)
• Hallucinations
• Insomnia
• Fluctuations in blood pressure
• Headache

Question 5

Which MOA-B inhibitor is preferred over the other and why?

Answer 5

Rasagiline is preferred
- Because Selegiline can cause hallucination and insomnia (best to take the last dose before 1 pm to avoid insomnia)

Question 6

Selegiline

Answer 6

• Amphetamine is one of its metabolites
  Driving offence (due to CNS stimulant effects)
• alopecia

Question 7

What time should the last dose of selegiline be taken and why?

Answer 7

The last dose should be taken before 1 pm to avoid insomnia and hallucinations
So best to take it in the morning

Question 8

Interactions - hypertensive crisis

Answer 8

Pseudoephedrine, phenylephrine, xylometazoline, oxymetazoline (OTC interactions: nasal decongestants)

Adrenaline, noradrenaline, methylphenidate, amphetamines, B2 agonists (drugs that increase BP: sympathomimetics)

Question 9

What foods do Monoamine-oxidase B inhibitors interact with?

Answer 9

Interacts with tyramine rich food
Mature cheese, salami, marmite, yeast, tofu