Sleep Wake Neurophysiology and pharmacology

Question 1

Monoamine Oxidase (MAO) A and B break down what neurotransmitters?

Answer 1

• MAO A
  
  • NE, Serotonin and tyramine
  • Dopamine
• MAO B
  
  • Phenylethylamine (CNS stimulant)
  • Dopamine

Question 2

Where are MAO A receptors located?

Answer 2

Intestine, placenta, liver and brain

Question 3

Where are MAO B receptors located?

Answer 3

Platelets and brain

Liver

Question 4

What are the MOA in atomoxetine (Strattera) that improve OSA?

Answer 4

Selective NE reuptake inhibitor

• Increase NE in sleep stimulates upper airway motoneurons to similar levels as in wakefulness

Blocks G-coupled inwardly rectifying potassium channels (Strongly rectifying Kir channels exhibit a very steep voltage dependence resulting in silencing of their activity at depolarized membrane voltages)

• These channels play important role in pharyngeal hypotonia during sleep by reducing hypoglossal motoneuron excitability

Question 5

How does oxybutynin (Ditropan) improve OSA and what is its MOA?

Answer 5

Antimuscarinic

Acetylcholine has an inhibitory effect on upper airway muscle tone during REM sleep

Question 6

Atomoxetine and oxybutynin decrease AHI by what number and what percent?

Answer 6

AHI: 28.5 to 7.5

A decrease of 63%

Question 7

What doses of atomoxetine and oxybutynin were used in a clinical trial to reduce OSA?

Answer 7

Atomoxetine 80 mg and oxybutynin 5 mg given qhs