Cardio: Nitrates

Question 1

Nitric oxide activates __________ in vascular smooth muscle.

Answer 1

guanylyl cyclase

Question 2

What does increased level of cGMP do inside cells?

Answer 2

It decreases intracellular calcium and deactivates myosin-light-chain kinase.(Think of how John Nitro gets to cut the P locks off of his Chain gang, just like how cGMP gets to cut phosphate groups off of myosin and prevent contraction.)

Question 3

True or false: nitrates primarily affect arteries.

Answer 3

False. It affects veins most, but also arteries (just like the blue pants of the prisoners set free by John Nitro).

Question 4

Nitrates mostly decrease ____-load.

Answer 4

pre (because of their effect on veins)

Question 5

Why are sublingual tablets commonly used for nitroglycerine?

Answer 5

Because the liver has a high first-pass metabolism on nitroglycerine, so bypassing it is helpful.

Question 6

Nitroglycerine has an extremely short half-life, so ___________ are used as maintenance therapies.

Answer 6

isosorbide dinitrate and isosorbide mononitrate (large doses)

Question 7

Although it has not been shown to decrease mortality, nitroglycerine has been shown to help with __________ in acute coronary syndrome.

Answer 7

pain and symptom relief

Question 8

Nitrates should be avoided in what kind of MI?

Answer 8

A right-sided MI, because they decrease pre-load; in this case, administer fluids to increase pre-load.

Question 9

Nitroglycerine can acutely reduce ___________ in the lungs.

Answer 9

pulmonary edema (Think of the pump operator with the wet lung spots.)

Question 10

What is pulmonary edema a possible symptom of?

Answer 10

Hypertensive emergency (think of the shutoff valve and how it represents NO shutting off hypertension)

Question 11

Nitroglycerine can lead to venous dilation that causes blood to pool in the extremities. What cardiac effect does this cause?

Answer 11

Reflex tachycardia (just like the doctor with his heart-shaped reflex hammer rushing in to help the fainting woman); beta-blockers can be given to counteract this undesirable effect

Question 12

What non-cardiac symptoms can nitro cause?

Answer 12

Facial flushingThrobbing headachesMethemoglobinemia (Think of the red-faced assistant, his obvious headache signs, and the rusty – oxidized –heme on the cart wheels.)

Question 13

What is tachyphylaxis?

Answer 13

Rapidly decreasing efficacy of a drug

Question 14

What drug can you not co-administer with nitrates?

Answer 14

Sildenafil and other PDE-5 inhibitors