ANS

Question 1

What do ergot alkaloid act on?

Answer 1

1. Alpha-adrenoceptors
2. 5HT
3. Dopamine receptors

Antagonistic (but also may be agonist)

SE: St Anthony’s fire (severe vasoconstriction :. gangrene)

Question 2

What is ergometrine?

Answer 2

1. Acts on all three receptors
2. Causes uterine SM contractions
3. Causes SM blood vessels constriction :. bleeding reduces

Question 3

What is bromocriptine used for and what is its MOA?

Answer 3

• D2 agonist
• Used for:
  
  • galactorrhea
  • parkinsonism
  • Fertility drug:
    
    • patients with lots of prolactin are usually infertile
    • release of prolactin under dopaminergic tone
    • so giving bromocriptine can reduce prolactin circulation by dopamine receptor agonist action

Question 4

What is phenoxybenzamine? MOA?

Answer 4

1. Non selective alpha antagonist
2. Use: osteohyperplasia

Question 5

What are prazosin and doxazosin?

Answer 5

1. Selective alpha 1 antagonists
2. Cause:
   
   • Fall in BP :. used in hypertension
3. Side effects:

• Nasal congestion
• Failure of ejaculation
• Miosis (pupil constriction)
• Postural hypotension (v. imp)
• Can get reflex tachycardia - baroreceptor reflex (inc. sympathetic drive to B1 receptors in heart)
• May see weight gain due to water retention (RAAS)

Question 6

What is atenolol?

Answer 6

1. Beta 1 specific antagonist
2. Use: Angina, MI, etc

Question 7

What is propranonol?

Answer 7

Cardio-non selective beta blocker

Question 8

What is carvedilol?

Answer 8

1. B1, B2 and A1 antagonist
2. Used in CHD

Question 9

What are the contraindications for beta blockers?

Answer 9

1. Asthma
2. AV block
3. Severe peripheral vascular disease
4. Diabetes –> can cause too much insulin due to blocking glycogenolysis (beta receptors in liver caluse glycogenolysis)

Question 10

What are the side effects of beta blockers?

Answer 10

1. Fatigue
2. Bradycardia
3. Cold extremities
4. Breathlessness
5. Sleep disturbance
6. Nightmares

Question 11

What is timolol used for?

Answer 11

• Closed angle glaucoma
• Non-selective beta blocker (reduced production of fluid in eye)

Question 12

What is bisoprolol used for?

Answer 12

• Hypertension

Question 13

What is the mechanism of guanethidine?

Answer 13

• Enters by uptake
• Local anaesthetic blocking Na channels
• Opening calcium dependent potassium channels
• Prevents action potential invading varicosity
• :. blocks adrenergic neurones

Question 14

What is the mechanism of reserpine?

Answer 14

• Reserpine deplete the vesicular stores of noradrenaline.
• Reserpine binds irreversibly to the vesicle transporter (VMAT) so that NA cannot be stored in vesicles.
• The NA is then “mopped-up” by MAO-A in mitochondria and broken down.
• Thus Reserpine impacts the storage of neurotransmitter, its effects can be reversed by using MAO inhibitors.
• Reserpine has been associated with increased depression.

Question 15

When is phentolamine used?

Answer 15

Used to reduce BP in emergencies