L8. Methylxanthines

Question 1

Methylxanthine Alkaloids:

Natural Product

Answer 1

Cafeine

theobromine

Theophylline

In foods, beverages, medications

Question 2

Methylxantinine Alkaloids:

MOA

Answer 2

Competitive antagonism of adenosine on adenosine receptors

Bronchodilation, vasoconstriction, tachycardia, CNS stimulation

Increases amounts of intracellular Ca

Inhibits phosphodiesterase

Increases cAMP → release of catecholamines

Stimulates the sympathetic nervous system

“Bouncing dog”

Question 3

Methylxanthine Alkaloids:

Pharmacologic outcome

Answer 3

• Cerebral stimulants = hyperactivity, agitation, seizures
• Myocardial stimulant = tachycardia
• Increased motor activity, over response to stimuli, tremors
• Diuretic = polyuria
• GI irritation = Vomiting, diarrhea

Question 4

Caffeine:

Sources

Answer 4

OTC stumulants, Coffee beans, Drip Coffee, Soda, Energy Drinks

Question 5

Caffeine:

Toxicity

Answer 5

Lethal dose:

Dogs: 110-200 mg/kg (LD50=140mg/kg)

Cats: 80-150mg/kg

Question 6

Theobromine:

Sources

Answer 6

Chocolate products or byproducts

Cocoa mulch

Question 7

Chocolate:

Theobromine Content:

Answer 7

Most:

Baking chocolate

Cocoa

Special dark sweet choc chips

Milk chocolate

White chocolate

Cocoa bean mulch

Least: