Device to Administer Doses Smaller Than .5 Units?

Like most folks on Lantus, I have been using the smallest U-100 syringe, which is the 3/10 mL (30 unit) size with half unit markings. Brutus started his treatment at 2.0 units. He's now down to .5, and likely to earn further reductions soon.

Is there a device that people use, other than the 3/10 mL syringes, to accurately administer doses less than .5? When you look closely at the very end of the 3/10 mL syringes, it is rather obvious that accuracy is impossible to achieve with doses much below 1.0 units. There is always some air in the cone shaped void where the needle attaches, which cannot be expelled no matter what. That air plus minor deviations in how each syringe is manufactured virtually guaranty that accurate dosage measurements under .5 cannot be achieved whether one employs magnifying glasses, calipers, rulers, or the like.

Is there some other device that can withdraw and accurately measure sub-.5 unit doses, yet also be used to administer it to the animal?

 

If you find something, be sure to post it on this message board! All of us would love to find something like it and all have looked with no success.

 

Uh oh. That's not good news. I figured I was the only one who wasn't in on the secret. Sounds like there may be no secret!!

 

Most of us use 4" digital calipers for the micro doses. I bought mine from Harbor Freight as did most everyone on here. Here is a link to lots of great information that may be of interest to you. I know the section on Dosing with Calipers will be. Scroll down the page. http://www.felinediabetes.com/FDMB/...the-basics-new-to-the-group-start-here.18139/

 

I remember reading something about counting drops. Eleanor has never been below .75, so I have no first hand knowledge.
There are also some syringes that don't have the cone that holds the extra insulin and bubbles. Easy Touch is one brand.

 

I'm happy to count drops, but what do you do with them once they're counted? Do you pull the plunger out of a second syringe and slowly add the requisite number of drops into it from a another syringe (and then put the plunger back and give the shot when your drop counting is done)?

I'll research syringe options, but I have a hunch that the BD brand syringes I am using are no different in how they work than other syringes.

There must be insufficient demand for syringes that dose .1 - .5 units. Otherwise, some manufacturer would find it profitably to design and sell a syringe that can administer such a small dose.

Frankly, that is such a small amount of medicine (especially for a big cat like Brutus) that I'm skeptical whether it makes any difference medically. Maybe it just makes more sense to stop injections and start an OTJ trial when the kitty earns reductions that take him or her under .5.

 

I don't know of any other devices other than the calipers some use today. Personally, I never felt the need to use calipers. I eyeballed micro-doses for years and Alex did very well... better than most. After all, when dosing, consistency is more important than accuracy. However, I can see how the use of calipers would be helpful if there's more than one person in a household drawing doses.

 

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I have also used the BD syringes (and many others) and really started to hate their inconsistency and very poor markings…

May I suggest you try the Monoject syringes? I’ve been these for about a month now and am very happy with them. The markings on the Monoject’s are great and very consistent (I have not found a bad one) - they are finely and clearly printed with the top (zero) line actually lining up with where the plunger ends up. The thickness of the plunger is also thinner which makes measuring the dose accurately much easier. I normally use them for doses between 1/2 and 3/4 unit which no issues (and also have given 1/4 unit a few times with no issue).

You may be interested in the following discussion I started on half unit syringes…

http://www.felinediabetes.com/FDMB/...surecomfort-and-bd-half-unit-syringes.158273/
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John and Derek

 

It may not look like enough insulin to make a difference, but I can assure you that it really is. My Rosa, as you can see from her spreadsheet, spent more time on micro doses than on any dose of 0.5 or above. And yet there was no way she could have held a remission had I simply stopped insulin from her 0.5u dose. Micro dosing may seem like an unnecessary hassle, but it really is very often needed to keep a cat in the healthy range without dropping them too low.

I eyeballed all the small doses too. For a couple of days when I ran out of half unit marked syringes, I even eyeballed a 0.1u dose using syringes with whole unit markings only. It's fiddly, but it can be done.

 

Thanks for the input. It's fiddly indeed.

 

It sure is. The only micro dose that I found easy was the 0.05u - that one I could do by holding the plunger down as hard as I could while putting the needle into the insulin vial, then releasing the pressure. That draws up just the tiniest drop of insulin and is a pretty consistent measure with no major effort. The 0.1u especially is a bad one to try and keep completely consistent, but the more practice you get, the easier it really does become.

 

When you count drops, what you do is start with a "known dose" like .5 or 1u (best to start out with water instead of insulin since you're going to waste a lot practicing)

Slowly push the plunger in (some people find "twisting" the plunger works better) until you can get the same drop size each time....Once you've got a consistent drop size, start counting how many drops you get in the "known dose"

Once you've got your drop count down (let's say you get 8 drops in .5), you'd pull up .5 into the syringe and if you want to give .25, "waste" 4 drops....that would leave 4 drops in the syringe (or .25)

If you want to give an even smaller dose, you'd "waste" more drops....Like if you waste 6 drops out of 8, that leaves you with a dose of 2 drops

It all depends first on practicing until you can get the drops the same size....then see how many drops you get in that "known dose" and do the math

 

If you want to invest in an autoclave ($$$$$), there are glass research syringes that micro-dose. The needles are disposable; the syringe is autoclavable for re-use. Hamilton is one company that makes them.

 

Great explanation. Thanks!!