Step I Pharm question

[SML67]

Advertisement - Members don't see this ad

Your post-mi patient needs long-term drug support to prevent MI #2. Which drug will offer relief from excessive afterload and protection from elevations in sympathetic NS activity during the day?

Propanolol
Atenolol
Nitroprusside
Diltiazem
Nitroglycerin

Thoughts? I'll wait for a few responses before giving the answer.

 

[Myxedema]

Which drug will offer relief from excessive afterload and protection from elevations in sympathetic NS activity during the day?

This must be a drug that causes (1) Vasodilation (to decrease preload) and (2) Cardioinhibitory (to protect from SNS activity). The only drug on that list with both of these actions is diltiazem. In fact, diltiazem is known for its difference from DHP type of calcium channel blockers (such as nifedipine) by decreasing arterial pressure without reflex tachycardia.

 

[chaotic mind]

there are 3 important points in this question
1.afterload reduction
2.protection from excessive sympathetic stimulation
3."during the day"
betablockers would protect from sympathetic stimulation and decrease afterload(beta 1 receptors are stimulatory for renin release)
so it comes to propanolo and atenolol
propanolol causes cns side effects(sleepiness)

so whats the answer?

 

[SML67]

there are 3 important points in this question
1.afterload reduction
2.protection from excessive sympathetic stimulation
3."during the day"
betablockers would protect from sympathetic stimulation and decrease afterload(beta 1 receptors are stimulatory from renin release)
so it comes to propanolo and atenolol
propanolol causes cns side effects(sleepiness)

so whats the answer?

This was a clicker question. The prof gave credit for diltiazem, but there was a moderate uprising from about 10-15% of the class that chose atenolol. I'm still not convinced that diltiazem is a better answer.

 

[LuckiestOne]

This was a clicker question. The prof gave credit for diltiazem, but there was a moderate uprising from about 10-15% of the class that chose atenolol. I'm still not convinced that diltiazem is a better answer.

What school is this?

 

[Myxedema]

This was a clicker question. The prof gave credit for diltiazem, but there was a moderate uprising from about 10-15% of the class that chose atenolol. I'm still not convinced that diltiazem is a better answer.

Atenolol is a beta1-selective drug. It has no direct effect on vasculature. On the other hand, diltiazem will block the calcium channels on both the vessels (causing vasodilation --> afterload reduction) and the heart.

 

[Phloston]

Your post-mi patient needs long-term drug support to prevent MI #2. Which drug will offer relief from excessive afterload and protection from elevations in sympathetic NS activity during the day?

Propanolol
Atenolol
Nitroprusside
Diltiazem
Nitroglycerin

Thoughts? I'll wait for a few responses before giving the answer.

A) In terms of afterload:

We'd want something that dilates the arteries/arterioles, which could be nitroglycerin (high doses), nitroprusside or diltiazem. However, nitroglycerin is not normally prescribed prophylactically for the sake of decreasing afterload (instead, it's used for reducing preload), and nitroprusside is classically used in malignant hypertension, so diltiazem is the only drug that makes sense here in terms of decreasing afterload. Notice beta-blockers don't fall into this category (except for carvedilol and labetalol, which aren't listed).

B) In terms of offering protection from elevations in daily SNS activity:

Chaoticmind nailed it in terms of beta-1 inducing renin release, but beta-1 blockage, per medication, isn't used to regulate renin levels. So although this was great thinking, it doesn't apply here. Reducing SNS activity during the day implies reducing HR/inotropic state (beta1 or Ca2+ channel blockage) or mitigating vasoconstrictve effects. While the SNS effects at the heart could be curtailed using either atenolol or propranolol, diltiazem both works at the heart and reduces vasoconstriction of the vasculature.

Not only is diltiazem the better answer for lessening SNS activity, it is also the only drug that falls into both categories A and B above.

 

[chaotic mind]

This was a clicker question. The prof gave credit for diltiazem, but there was a moderate uprising from about 10-15% of the class that chose atenolol. I'm still not convinced that diltiazem is a better answer.

I was stumped because i read too much into "the day" bit and they wanted to prevent another MI(beta blockers reduce mortality and prevent MI).
so much for overanalysing questions.

 

[OveractiveBrain]

Your post-mi patient needs long-term drug support to prevent MI #2. Which drug will offer relief from excessive afterload and protection from elevations in sympathetic NS activity during the day?

Propanolol
Atenolol
Nitroprusside
Diltiazem
Nitroglycerin

Thoughts? I'll wait for a few responses before giving the answer.

This question makes me angry. Take out all his blah blah blah about how he's going to be trixy with wording and quiz you on obnoxious details about pharmacology. You give post-MI patients Beta Blockers. Period.

Dilt is used for rate control (it slows the AV nodal conduction) and does little for peripheral arteries.

Nitro is a venodilator and, while it decreases workload of the heart, reducing demand ischemia, doesn't do anythign for arteries.

Nitroprusside is the only medication listed that drops afterload. It causes cyanide toxicity.

Propranolol is used in variceal bleeding and stage frieght.

Im not saying anyone above me is wrong, only that if you are going to learn something in a pharmacologic view, it should mirror what you do in practice. BETA BLOCKERS FOR MI