Foxglove

1
Foxglove

• Calypsa Padon
• Russ Cunningham
• Nicole Keller

2
How about a cup of tea???

• Alice adds some foxglove to a cup of tea
  because she has heard that it has many medical
  benefits. Soon after her tea, she develops some
  serious problems. In fact, foxglove is often
  used to treat some heart conditions.

3
Foxglove

• Active Ingredient Digitalis
• One of the cardiac glycosides
• Used to
• -strengthen cardiac contractility
• -antiarrhythmic agent (regulates heart rhythm)

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Cardiac Glycosides

• Inhibit the sodium/ potassium pump
• -Increasing the amount of intracellular calcium
• -Na builds up in the cell, inhibits calcium
  removal from the cytosol
• -Strengthening/ prolonging the contraction

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The Cardiac Conduction System

• Cardiac Glycosides also
• Prolong the refractory period at the AV node
• Decreasing the number of impulses reaching the
  ventricles therefore, controlling rhythm
  irregularity
• Increase sensitivity to parasympathetic impulses
• an interaction may exist between parasympathetic
  stimulation and Digitalis

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So what about Alice?

• Overdose can cause
• -Jaundiced vision
• -Blurred outlines (orange halo)
• -Bradycardia (and death, in severe cases)

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Or, did Alice just want to lose some weight?

• A common side effect of Foxglove is a loss of
  appetite, therefore, it is often abused for its
  weight loss qualities.

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Analogy Mad Hatters tea party

• Mad Hatter inhibits Alice from pursuing the white
  rabbit
• -cardiac glycosides inhibit the Na/ K pumps
• Alice must stay at the tea party
• -Ca must stay inside the cell
• Prolonged delay at the Mad Hatters
• -Prolong refractory periods at the AV Node
• Decreased amount of time finding the white rabbit
• -Decreased impulses reaching the ventricles

9
Questions?