Metaraminol

Question 1

How does metaraminol work?

Answer 1

Potent sympathomimetic amine

Synthetic direct and indirect-ating sympathomimetic

Acts on alpha1-adrenoceptors to increase BP via SVR. Minimal B adrenoceptor effects. No effect on cardiac contractility

Question 2

What are the uses of metaraminol?

Answer 2

Hypotension

Priapism (off-license)

Question 3

What is the absorption/distribution of metaraminol?

Answer 3

• IV administration
• dose effective within 1-2mins
• lasts 20-60 min

Question 4

What are the CVS effects of metaraminol?

Answer 4

• increases SVR (which may decrease CO)
• increase BP
• increase coronary artery blood flow
• increase pulmonary artery pressure and vascular resistance

Question 5

What are the respiratory effects of metaraminol?

Answer 5

• increased RR
• increased tidal volume

Question 6

How is metaraminol metabolised?

Answer 6

Hepatic metabolism

Question 7

What are the other effects of metaraminol?

Answer 7

• decreases uterine blood flow
• uterine contractions = avoid in pregnancy
• decreases CNS blood flow
• inhibits insulin release and glycogenolysis - causes hyperglycaemia
• increases lipolysis
• increases basal metabolic rate and temperature

Question 8

What are the side effects of metaraminol?

Answer 8

• severe hypertension
• nausea and vomiting
• tissue necrosis with extravasation