Ergot Alkaloids - Pharmacological Effects

Question 1

What are the effects of ergots at the CNS?

Answer 1

• LSD is a potent hallucinogen (5HT2 antagonist in the periphery but agonist at the CNS, also a D2 agonist)
• bromocriptine is a D2 agonist used in the treatment of Parkinson’s disease and hyperprolactemia

Question 2

What are the effects of ergots at vascular smooth muscle?

Answer 2

They are partial alpha-1 agonists which constrict blood vessels. Can be used for epinephrine reversal (because it competes with epinephrine for alpha-1 receptors)
- are used to treat migraines because of their 5HT-2, 5HT-1b/1d plus alpha-1 agonist properties

Question 3

What are the effects of ergots at uterine smooth muscle?

Answer 3

• Contracts the uterus. Not used to induce labor.
• At small doses rhythmic contraction of the uterus
• at-large doses powerful and prolonged contraction

Question 4

Which are the uterine selective ergots?

Answer 4

Ergonovine (Ergotrate)
Methylergonovine (Methergine)

Both have a “no” in the name

Question 5

Do ergots have significant effects on bronchial smooth muscle?

Answer 5

No

Question 6

How does ergot toxicity (ergotism) manifest itself?

Answer 6

• Nausea and vomiting
• diarrhea
• thirst
• pruritus
• vertigo
• muscle cramps
• paresthesias
• cold skin
• gangrene