Loop Diuretics

[htyotispharm]

Hey guys

One of the internists at the hospital where I'm doing my rotation ask us what was the name of the first loop diuretic? After I proudly gave the answer as ethacrynic acid he then asked me why was it so different from the other loops? I've been looking everywhere but can't come up with much. So far all I have is that EA binds to cysteine complex and therefore has a pharmacological effect even after furosemide-binding sites are saturated or down-regulated. In this way, EA can ameliorate hypervolemic states that are the final common pathway of both cardiac and noncardiac causes. However, he mentioned something about the structure moiety.

I'm stumped

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[KARM12]

Come on now, this one isn't too hard!

Ethacrynic Acid doesn't have a sulfanomide group, therefore it can be given to patients with sulfa allergies. The other loops all have a sulfa group.

 

[museabuse]

Hey guys

One of the internists at the hospital where I'm doing my rotation ask us what was the name of the first loop diuretic? After I proudly gave the answer as ethacrynic acid he then asked me why was it so different from the other loops? I've been looking everywhere but can't come up with much. So far all I have is that EA binds to cysteine complex and therefore has a pharmacological effect even after furosemide-binding sites are saturated or down-regulated. In this way, EA can ameliorate hypervolemic states that are the final common pathway of both cardiac and noncardiac causes. However, he mentioned something about the structure moiety.

I'm stumped

Off the top of my head it is the only diuretic you can safely give to someone with a true sulfa allergy...

 

[museabuse]

Come on now, this one isn't too hard!

Ethacrynic Acid doesn't have a sulfanomide group, therefore it can be given to patients with sulfa allergies. The other loops all have a sulfa group.

damn you beat me!

 

[sdn1977]

Hey guys

One of the internists at the hospital where I'm doing my rotation ask us what was the name of the first loop diuretic? After I proudly gave the answer as ethacrynic acid he then asked me why was it so different from the other loops? I've been looking everywhere but can't come up with much. So far all I have is that EA binds to cysteine complex and therefore has a pharmacological effect even after furosemide-binding sites are saturated or down-regulated. In this way, EA can ameliorate hypervolemic states that are the final common pathway of both cardiac and noncardiac causes. However, he mentioned something about the structure moiety.

I'm stumped

Well.....since he brought up the structure of both....how about looking at the structure of furosemide/torsemide & ethacrynic acid?

Ethacrynic acid does not contain a sulfa radiacal & may be used in pts who are cross sensitive to sulfa drugs.

This is a REEEAAAaaallllll stretch! I've only had 2 pts in 30 years who had such a sulfa allergy they couldn't take furosemide or toresemide.

But...that's what my guess would be with this question. Look again at the structures......

 

[htyotispharm]

my preceptor brought up the lack of sulfa group but that wasn't it according to the internist

 

[sdn1977]

my preceptor brought up the lack of sulfa group but that wasn't it according to the internist

Well.....both furosemide & bumetanide are inhibitors of carbonic anhydrase (since both are weak sulfonamides), but they don't contribute to proximal diuresis unless huge doses are used.

Ethacrynic acid is not a carbonic anhydrase inhibitor & may act at a different Na-K-2Cl site other than the site that furosemide, torsemide, bumetanide works at.