u100 vs. u40 PZI

Oh, I should be able to do the math, but I've been pondering this for a while because some of the new kids on the block are using u100 compounded PZI.

From the conversion chart : "U-100 will have 100 units per mL, and U-40 has 40 units per mL. This means that U-100 has 2.5 times the amount of active insulin per mL, therefore 2.5 times as strong. "

So then, how does 1u of u100 PZI compare to 1u of u40 PZI? Is 1u of u100 PZI delivering more or less or the same amount of insulin as u40 PZI? Is it the same amount of insulin per unit, but u40 has more volume then u100?

I don't mean to confuse things, but I've been trying to figure it out for a while.

 

I'm curious because the advice I often see given to newbies using u40 PZI or ProZinc is to start over at 1u, especially when a newly diagnosed diabetic cat is being switched from a high carb dry food to a high protein wet food.

But does this advice still apply to a cat that 1) has always eaten relatively low carb wet food and 2) is on u100 compounded PZI. And should weight be taken into account?

Just musing about the 1 size fits all approach.

 

Hmmmm, clearly a brain teaser here. I think the unit is an arbitrary measure that correlates the insulin to the syringe - 1u of U-100 insulin in a U100 syringe is the same as 1u of a U-40 insulin in a U-40 syringe. The conversion table tells you how to measure that same arbitrary amount in the alternate syringe. So U100 is 2.5x stronger than U40 if you are swapping syringes (which is what is controlling the volume change), but a unit in the correct syringe for that insulin is always a unit. U100 has more insulin per mL, but we measure in units rather than mLs (I'm guessing that's why they invented the unit concepts, to have a universal measure rather than always having to do a conversion to measure by mLs? just a guess...)

Does that make any sense? So if I understand it right (which is somewhat in doubt!!!), the advice to start over at 1u is regardless of insulin strength (but assumes you are using the corresponding syringe, or if not, are using the conversion table).

I'm not sure about the weight question - you might try reading Dr. Rand's guidelines for lente insulin that you can get to via one of the stickies over on one of the L forums (I can hunt it down if you are interested & find the link). I don't think dosing is based on that in general, but I'm not 100% sure.

 

WOW, Joanna! I think you nailed that. I'm sure as much as our brains were spinning from the initial question... after reading your answer... that's what we wanted to say, but just couldn't put it in WORDS!

I've wondered about the weight issue too. Maybe we should somehow start a poll for this... it would be interesting. I know Pru had started at 2U at the vets office, but almost went hypo, so they sent me home doing 1U. She's 8.5 lbs

 

this is correct.

The vet told me the U40 "veterinary" insulins are obviously easier to fine tune doses for the smaller needs of animals vs humans.

Because of the cost issues for acromegalic cats (Cody 2 bottles of Prozinc /month) I have been researching the whole cost implications of this. U40 insulins have 400unit in a 10 ml vial. Insulins that are U100 have 1000 units in a 10 ml vial and therefore last 2 1/2 x as long ( in Cody's case - 5 weeks vs 2 weeks, assuming he stays on the same dose) . A vial of Prozinc cost me $84, a vial of lev cost me $101.

I love Prozinc and think it is a great insulin (stable, durable, gentle, predictable), but I am sorry to say that I am going to be trying lev for him soon ( I feel like a deserter @-) ) We almost started last Thursday, but he got REALLY sick overnight when we skipped a dose in order to start the new insulin. Vet thinks it was probably fluke timing and a virus, or maybe pancreatitis, but I bought a new vial of PZIR until he fully gets over whatever that was- kinda scary he looked terrible. Thought i might lose him.

 

Oh, I am so sorry to hear that happened to Cody. How's he doing today? You're lucky ProZinc only cost you $84. It cost me $130 :roll:

Hope you guys have a great weekend! Sending Cody healing thoughts & hugs to you :YMHUG:

 

Thanks Michele- he looks great today, in fact once he was back on insulin, and had a shot of cerenia for vomiting he was fine- he was just limp in my arms thurs morning and I was a zombie from cleaning smelly poop and vomit up till 4am (and it was the 2nd nght of way short of sleep)


Xrays, blood work, cerenia, giardai test, flagyl antibiotic for GI trouble and he's looking bright eyed again. read the ss for details. Its informative for the duration of PZIR for helping future beans esp acrobeans

 

Awww, Nancy, that sounds like an awful night. I'm glad he is better now! No shame in trying Lev, you have to do what you need to, especially with doses like that to budget for. Hope you are both totally recovered by now from the night-of-trauma and having a nice weekend!

 

Just got back from BREW AT the ZOO beer tasting to raise money- a buzz for a good cause - nice to get out for a change

Cody seems good- i just hope at some point he starts pooping again :lol:

 

1 marked U is 1 marked U

Nancy, mmmmm Beer - my fav! Good to hear you guys are on the Cerenia tip. It used to be a kind of a 'spooky' think for cats. It is a great drug but I am not convinced it gets rid of the nausea. But at least it prevents then from vomiting.