Physiology & Pharm Question

[EctopicFetus]

Physiology. According to Costanzo BRS it says the the Blood Pressure in the renal artery is higher than in the aorta? Is this right it says that it has to do with the angles that the fluid travels. I think this doesnt make sense cause since Q=dP/R dictates flow, if your make the dP negative then fluid would flow backwards..

Pharm...

What meds would you give someone who has a history of Ulcers and you are trying to control the pain associated with Rheumatoid Arthritis? Qbank said you can used COX-2 selective NSAIDs but the PDR and other sources say that this can also cause GI bleeding. Anyone know?

Thanks in advance.. Boards are around the corner and my little brain is filling up with information. Before I know it I wont be able to name the whole Miami Dolphin roster backwards!!! AHH

---

Members don't see this ad.

 

[Rod Farva]

I'm pretty sure you get less bleeding with COX-2 inhibitors in the stomach, but it can still occur... maybe toss some misoprostol in there to protect the mucosal barrier? I don't exactly know what they're getting at if that's not it... I would say COX-2 is still the way to go.

 

[Idiopathic]

There is very little COX-2 in the stomach, so PGE is normally produced and is able to protect the gastric mucosa.

As for the renal artery, some things just are...I could probably handle that one if it wasnt 12:39, and I wasn't already tipsy...

 

[jakstat33]

There is very little COX-2 in the stomach, so PGE is normally produced and is able to protect the gastric mucosa.

As for the renal artery, some things just are...I could probably handle that one if it wasnt 12:39, and I wasn't already tipsy...

ya got a fake ID?

 

[Idiopathic]

yeah, your mom's...

(does that even make sense?)

 

[BrooklynDO]

Physiology. According to Costanzo BRS it says the the Blood Pressure in the renal artery is higher than in the aorta? Is this right it says that it has to do with the angles that the fluid travels. I think this doesnt make sense cause since Q=dP/R dictates flow, if your make the dP negative then fluid would flow backwards..

Pharm...

What meds would you give someone who has a history of Ulcers and you are trying to control the pain associated with Rheumatoid Arthritis? Qbank said you can used COX-2 selective NSAIDs but the PDR and other sources say that this can also cause GI bleeding. Anyone know?

Thanks in advance.. Boards are around the corner and my little brain is filling up with information. Before I know it I wont be able to name the whole Miami Dolphin roster backwards!!! AHH

I dont know what the choices were... but i have a feeling that the point of the question was : ok you got a pt with rheum and he has ulcers, and the rheum pain is bothering him and you gotta give em something, so which one is the less evil to give of the choices listed? You would have to make sure that the other choices were not what you give... misoprostol isa good idea except thats not what they are asking about... they arent asking the whole management...eg miso etc for the ulcers (management classic i believe is metro, bismouth and amoxicilin or a tetracyclin), just about the rheum

also question basically reads :which one of these is least likely to cause bleeding in a ulcer pt

~Brooklyn

 

[mpp]

Physiology. According to Costanzo BRS it says the the Blood Pressure in the renal artery is higher than in the aorta? Is this right it says that it has to do with the angles that the fluid travels. I think this doesnt make sense cause since Q=dP/R dictates flow, if your make the dP negative then fluid would flow backwards..

Doesn't sound right to me. What page? or quote the text.

 

[EctopicFetus]

2nd Edition Costanzo, page 110 Question # 3, answer is given on page 116. All the other answer choices are ******ed so you are left with Aorta and Renal Artery. Here is a direct quote "In the systemic circulation, pressure is actualyl slightly higher in downstream arteries (e.g. renal artery) than in the aorta because of the refl;ection of pressure waves at branch points." What the hell are they talking about? More help on this please!!

 

[TysonCook]

If the pressure was higher than you would not get any flow into that artery, regardless of angles, velocity or magic pixie dust (just going from physics) High pressure to low pressure, everything works that way......maybe if it was under the influence of a hormone that was vasoconstricting, but that's a great way to have renal failure. It could be at 1 specific point on the wall (wall tension), but the overall average of pressure must flow from high to low.

As far as COX-II goes, at least our pharm class told us that they still will cause ulcers in some populations as 1)they are NOT 100% specific COX-II, so they will still inhibit some COX-I, giving a slight chance of ulcers. BUT OVERALL they are still much better Rx than non-specific COX inhibitors. 2)The original tests that they did for the -coxib's had been found to be less signifcant than they had originally thought, and during phase four trials they are coming up w/a larger % of people that still do, or are having GI issues, but once again, at a lower rate than just non-specific COX blockers.

So I think that given the choice, COX-II will be a better Rx, even though it slightly shows some ability to cause GI issues. If you had to have 100% no bleeding, then you could add to another Rx -prazols, -tidines, -miso etc.

HOpe this helps, as this is what our prof told us.....

 

[Kalel]

You can have higher pressure in distal arteries and still have blood flow into them. From a physics point of view, I guess that the pressure isn't always higher in the those arteries then the aorta, there are times when the pressure is less and that's when the blood flow occurs? I'm not sure. Anyways, one example of having different blood pressures in distal areas would be in coarctation of the aorta, but you still have blood flow to those regions with higher BP's. And COX-2 inhibitors are appropriate for patients with histories of ulcers, but you should add other rx's to them to protect your stomach as the previous user mentioned, and you shouldn't discount the possibility of them causing ulcers (as physicians used to do, up until a few years ago).

 

[nuclearrabbit77]

i believe that the answer in costanzo should be interpreted as 'maximum' systolic bp, not as the average bp of the renal artery. as the explanation mentions, at the bifurcation (which i assume is the aorta/iliac), a pressure wave is reflected back and a very high peak in pressure occurs, similar to how resonance and constructive interference occur in wave mechanics.

i don't see why a question like this should be in a brs book.

 

[DRealDrZ]

TysonCook is correct as far as the COX II question.