Insulin and Starting Scales, Diabetic Cat Care

The information contained in this sticky is provided for educational purposes only and is not intended to replace veterinary advice. The intention of this sticky is to open doors to understanding about the specific medical condition or topic, allowing for educated and on-going discussion with your vet.

Diabetic Cat Care

How Different Insulin

Types Work,

Making Sure You Have

The Right Syringes

& Starting Scales For

There's no doubt there's a lot to learn when it comes to Feline Diabetes and we strongly recommended reading all the information about insulin provided in this sticky in its entirety to help you understand the many and various aspects about the insulin you're using. There's no expectation for you to remember everything you'll read, and when you need to come back and review specific topics, these shortcuts are provided for your convenience;

Understanding Method of Action
Storing and Handling Insulin
Using Insulin To Your Advantage - The Basic Principles of TR
Changing Insulin Types
Syringes - Do You Have the Right Ones???
Fast Acting (Bolus) Insulin
Intermediate Action Insulin Types - How They Work In Cats
.....PZI (BCP VET, Stokes, Summit)
.....ProZinc
.....Caninsulin/Vetsulin
.....NPH / Humulin N / Novolin N
Starting Scale for Intermediate Action Insulin
Long-Lasting (aka Basal) Depot Insulin Types - How They Work in Cats
......Lantus / Glargine
......Levemir/Detemir
Starting Scale for Long-Lasting Depot Insulin

Sometimes we'll have a choice when it comes to which insulin type is prescribed by our vet, sometimes we won't. The most important thing to know about insulin for feline use is that all types will work when it comes to TR. Understanding the properties and method of action of the various types of insulin available can help when it comes to determining which will work best for your personal situation. Availability, price, type of insulin (depot or intermediate-action), and what the insulin is made of are some factors to consider in the selection process.

Most of us arrived at DCC with insulin already prescribed by the vet. Then, after finding DCC and reading about different insulin types, it's not abnormal to be concerned the insulin that we've been prescribed isn't the best for our cat. If that's they case, don't worry....while each type of insulin has its pros and cons, giving vet-prescribed insulin a chance is the best thing you can do - first. Every cat responds to insulin differently, and once you're practicing TR, it could be that your cat will all of a sudden start doing some amazing things. Allowing your cat the time to show you what it will do when you're giving the right amount of insulin at the right time will confirm or deny whether or not the particular insulin is going to work. If expected results don't happen, then when you've collected the data you'll need, you'll be armed with your test log (and more knowledge) when it comes time to request a different insulin type from your vet, if that's necessary.

If your situation is that insulin hasn't been prescribed yet, then reading about the different types available and the unique properties each has will open the door for discussion with your vet based on your individual circumstances.

As important as it is to understand the differences when it comes to insulin action, it's also important to understand insulin is made two ways; either it is manufactured which allows for precise consistency from vial to vial/batch to batch. Or is it compounded; each batch is made separately and variances in potency etc., can occur from batch to batch. In addition, sterility issues are very common when it comes to compounded insulin products as exposed in a 2012 study of compounding pharmacies. For this reason, many vets are now refusing to prescribe compounded insulin types. As far as is known today, BCP Vet has not ever recalled any insulin products due to potency or sterility issues.

Understanding Method of Action

There are two primary types of insulin used for diabetic cats. The first is what are considered as intermediate action insulin types - this group includes bovine based PZI and salmon-based ProZinc, Caninsulin/Vetsulin, and NPH/Humulin N. The second type of insulin is longer lasting because it is depot insulin - building a depot inside which releases into the system at a slower rate of absorption. Long-lasting Depot insulin types include Lantus/Gargline and Levemir/Detemir.

If your cat is not yet on insulin, reading about the various types available will help to determine which one is best for you and your cat. If your vet has already prescribed insulin, reading about the type you have been prescribed can help you understand why it is you may not be seeing the results expected, and help you understand what changes need to be made for your cat.

One thing is for certain when it comes to all insulin types - they don't last as long inside as the vet community at large believes. This truth has been proved time and time again, and will be very easily confirmed with a curve to determine when onset and nadir occur, and most importantly, when the insulin starts to leave your cat's system. Depending on the insulin type, it usually starts to leave the system anywhere from +6 to +10 hours after shot. One of the reasons why TR works so well is because we give our insulin earlier than every +12 hours, creating overlap between doses which is used to our advantage. This is something Dr. H has known for more than 10 years, and is one of the driving forces when it comes to TR's success. Once the cats have been on TR for a short amount of time, they'll typically start to stretch out their durations on shots and might even start to skip shots as they heal.

Storing and Handling Insulin

Insulin should be stored in the fridge at all times, in a sturdy, padded container in a protected spot on a less-used shelf where it will not get knocked over - inside a coffee cup lined with paper towel is a good idea. Do not store insulin on the door of your fridge to avoid excess jostling every time the door opens and closes. Do not worry too much if you happen to forget to put your insulin back in the fridge sometime - most of us have done that! As long as the insulin wasn't near a heat source or in direct sun, it shouldn't be damaged.

Practicing TR we handle our insulin more often than when dosing only twice a day. Insulin is relatively fragile-particularly compounded insulin types - so handling your insulin gently and giving it proper care will prolong potency considerably. Most insulin types need to be gently turned end over end a few times to ensure the suspension is well mixed. This applies to PZI, ProZinc, Caninsulin/Vetsulin.When preparing a shot of these insulin types, draw the syringe's plunger back to your needed dose prior to inserting the needle in the vial, insert the needle through the rubber stopper and inject the air into the vial. Then, turn the vial upside down with the needle still in it and draw just past your needed dose before removing the syringe from the vial. Look for any bubbles in your syringe - if they're present, flick the syringe with your finger a couple of times until the bubbles are at the top of the barrel, just under the needle. Push the plunger up slowly until you see a small drop of insulin which should indicate air bubbles are gone. If not, wash, rinse, repeat until there are no longer visible air bubbles. Typically once a small drop of insulin appears at the tip of the needle that's an indication air has been expelled and it's time to double check you have the amount of insulin you want to give and then proceed to give the shot.

Lantus and Levemir should not be rolled or shaken - if ever there are flakes in the vial or cartridge, the insulin has been damaged and should be thrown out. In the case of Lantus, air should never be injected into the vial or cartridge as this damages the crystals in the insulin (the same does NOT hold true for Levemir apparently). Should it happen that air bubbles form in a Lantus cartridge/vial, they can be removed with some hard work, and may if lucky, dissipate if the cartridge/vial is left to sit quietly for a while.

Using insulin to your advantage - The Basic Principles to TR

Please keep in mind, TR is not a traditional veterinary treatment protocol - TR is actually designed to navigate your cat into diet controlled diabetic remission - OTJ - Off The Juice. TR is not designed to keep you as a frequent flyer at the vet clinic. TR takes advantage of the fact that your cat's diabetes has far more chance of going into remission if it is aggressively treated as soon after diagnosis as possible. TR is not without effort, or some sacrifice at times - it isn't always convenient but it works! Your vet will likely not be supportive of TR but the best weapon you will have when it comes to educating them is your test log. The data does not lie!

It is advised to start TR / insulin when you are available to monitor your cat’s BG frequently by performing curves for the first few days until you know how your cat processes their insulin. The criteria you need to know is when onset occurs (how many hours after shot does the insulin start to work); when nadir takes place (the lowest BG on the shot/when the insulin is most powerful), and when the insulin starts to leave the system. Once the approximate timing of these events is known, then certain tests aren't necessary unless results at nadir don't make sense.

One of the important foundations of TR is built on is maintaining overlap between doses – what overlap means is, the remnants of the prior shot are still working to keep the BG from rising very high, while the next shot approaches onset (when the insulin starts to work). For most insulin types, dosing only every +12 hours results in there being no (or little) insulin left in the system between shots allowing the BG to spike quite high. Different insulin types have different durations - experienced members on forum will help guide you through the process of understanding the nuances of the specific insulin you are using and more importantly, will explain the results of your BG testing to help you get maximum benefit from overlap between doses.

When starting TR (or increasing/decreasing insulin scales, changing insulin types, etc.) the testing is critical as it tells you what your cats needs in terms of timing and amount of insulin. The Starting Scales provided are only that "starting" scales and you should expect that adjustments will be made relatively quickly to get your cat's BG to where it needs to be. While the vet may not want to change insulin amounts or even see your cat for a few weeks or more, that isn't the way Dr. Hodgkins taught us to do things! We don't want to leave the cats in higher BG than necessary for any longer than necessary - all that does is allow for damage to occur to internal organs. Once a cat has completed the Detox Process to low carb wet food so their liver is wide awake and ready to do its job (usually within 24 hours), increases to their dosing scale will start in a methodical and assertive way.

The goals for the first week on TR are to navigate your cat into BG consistently below Renal Threshold (the point where ketones can be produced) and then down into ideal range non-diabetic numbers if that is possible. Ketones are not usually produced at BG below 225-250/12.4-13.9 - ideal range non-diabetic BG are between 50-70/2.8 to 3.8. Many folks (and most vets) have grave concerns these ideal range numbers are too low but they truly aren't for cats. Most non-FD cats routinely test between 50 to 70 /2.8 to 3.8. If you have any doubts, test one of your other cats, or test a friend's cat. Once you see the BG of a non-diabetic cat taken in the comfort of their own home, we guarantee you'll breathe much easier! We often wonder why it is the vets don't know what the normal BG of a non-diabetic cat really is; in their defense, the cats who's BG they test are stressed at the clinic - just like white coat syndrome humans experience.

The most important thing to understand is that TR is a very SAFE protocol because of the non-negotiable requirement for an all wet low carb diet protecting otherwise healthy diabetic cats from clinical hypo, coupled with an aggressive approach specifically designed to avoid the production of ketones which in turn protects from DKA (Diabetic Ketoacidosis). Please, before making any changes, review the Detox Process sticky for further information about starting TR safely to prevent clinical hypo.

Changing Insulin Types

Sometimes it becomes necessary to make a switch to a different insulin type. There are many valid reasons to consider changing insulin types; the expected results aren't being achieved after trying all the standard methods to confirm or deny what the issue might be. It is possible the current insulin has worn itself out as far as the body goes if your cat's been on it for a long time, or it's possible an ingredient in the insulin is or has become an antagonist to your cat. On a personal level, perhaps life has got in the way and a longer lasting insulin type is needed to make things more manageable for a long-term diabetic cat.

When switching insulin types there are a few things to take into consideration before giving the first shot of the new insulin.

-What method of action/type of insulin has the cat been on?
-How long do they typically last on shots of the current insulin before it starts to leave the system?
-What is the current dosing scale?
-Is the cat prone to quickly producing ketones?
-Will you be available to do curves/test for the first few shots of the new insulin type?

When switching insulin types, the ideal situation is that the change is made when the cat's coming off a good run in ideal, non-diabetic numbers specifically because they likely won't be producing ketones. Making an insulin switch always allows for that possibility, so it is very wise to be prepared to be testing for ketones (whether for urine ketones or blood ketones). Adding a bit of extra water to your cats food during an insulin switch will help (but not prevent) the production of ketones. Close monitoring of BG and for ketones is strongly recommended when any changes are made.

If switching from intermediate-action insulin types (PZI, ProZinc, Caninsulin/Vetsulin and NPH, it's recommended to leave 12 hours between doses as a rule of thumb. If your cat has been having longer durations than +12, then the number of hours between doses of the two insulin types could be extended further apart.

If switching from a long lasting depot insulin type like Lantus, Levemir, then an extended amount of time between doses is recommended depending on durations being achieved prior to the switch - for example, 18 to 24 hours might be best between the old insulin and new.

The saying ECID - Every Cat Is Different - rings very loud and very true when it comes to making an insulin switch. Regardless of the type of insulin, taking a look at what the cat HAS been doing, how much insulin they've been getting, whether they're a cat prone to ketone production or not should all be taken into consideration when contemplating an insulin switch. It could be that based on your cat's past history, the scale for the new insulin will be the posted starting scale, or not. If it's a situation were a cat's scale has been 5.0u at the first rung dose, regardless of insulin type they're switching to - it's highly unlikely they'll be able to get by with a first rung dose below 0.5u and will need a higher scale to start the new insulin.

Please ask for input on forum if you're contemplating making a switch of insulin specifically to make certain that everything which should be done has been to confirm or deny a change of insulin type is necessary or recommended. Experienced members will also be able to help you determine what the best starting point is for your cat based on their patterns and results - and will lay out a game plan for you so you understand what to look out for. We strongly recommend working with an experienced member - rather than going it alone - when changing insulin types as they have the understanding and confidence should aggressive steps be necessary if things don't go as planned.

Specific Insulin and Starting Scales Information

OOPs......one last but very important topic first!

Syringes - Do You Have the Right Ones???

It is imperative you have the correct syringes. U40 syringes (for U40 strength insulin) are now available with HALF UNIT MARKS, they can be ordered through your vet but are much less expensive buying them online. U100 syringes (for U100 strength insulin) come in many different sizes.....the ONLY ones you want for TR are U100 3/10cc for 30 units of insulin or less WITH HALF UNIT MARKS. Again, these can be purchased through your vet but are much, much less expensive buying through DCC's Affiliate Partners, online or in stores. For further information about the differences in syringes available, please post on forum - fellow members will be happy to share their preferences when it comes to which syringes they like best and why.

Please be aware that there are several sizes of U100 needles, each holds different amounts of fluid - 3/10cc/ml, 1/2cc/ml and 1cc/ml. The 3/10cc and the 1/2cc both have draw lines on the barrel that equal one unit, while each of the draw lines on the 1cc syringe equals two units. It is important NOT to buy 1cc syringes, as the 2u draw lines can make it very easy to overdose! We strongly recommend buying ONLY U100 3/10cc syringes for 30u of insulin or less - with half unit markings! If you're not sure what you have, please post on forum for further assistance.

When it comes to insulin, the latest rage for pets is about Injectable Insulin Pens which are either disposable or can be refilled with cartridges. Unfortunately while pens are very convenient and can seem less scary, using a pen only allows for half or full unit doses to be administered. Disposable pens are more difficult when it comes to a accessing the cartridge of insulin. If you are able to get packages of pen cartridge refills - without the pen - this is highly preferred over buying individual pens - also more cost effective. Most all insulin types except for ProZinc are available in disposable or refillable pen forum or in vials. While the pens and cartridges are more expensive than a 10ml vial, there's far less waste if something happens to damage a cartridge of insulin which contains only 3ml. Alternatively, one pen at a time can be purchased. To use the cartridge part of the pen you'll need to get access to or remove the cartridge in order to use syringes which allow for finer and more accurate dosing adjustments. Using syringes when practicing TR allows for far more accurate and precise doses of insulin for your cat. It's very common for us to see that only a miniscule amount of insulin - as little as only 0.125u less or more on a shot can make a huge difference for some cats!

Important Info! Intermediate insulin types come in a variety of strengths, the two most common are U40 (40% insulin/60% suspension) or U100 (100% insulin). Depending on which strength your insulin is, you will need syringes to "match". Both U40 and U100 3/10cc insulin syringes WITH HALF UNIT MARKS are recommended to help you measure doses as accurately and consistently as possible. Typically the vet clinics don't sell these, they can order them but the cost will be much higher than getting a prescription and ordering them yourself. Please refer to your country specific information sticky for sources to purchase syringes with half unit markings for far less money than you'll pay buying them from the vet.

U100 3/10cc insulin syringes CAN be used with U40 insulin, however the reverse is NOT the case. Please visit the TR College of Knowledge for more information about insulin syringes, and as well information about how to convert doses when using U40 insulin with U100 3/10cc syringes. Members on forum can help you confirm you have the right syringes for your insulin type.

Specific Insulin and Starting Scales

Please check the College of TR Knowledge specific country information stickies to determine what insulin types are available to you locally, or can be imported.

Intermediate-Action Insulin Types - How They Work In Cats

Curves for intermediate-action insulin types usually prove onset occurs between +2 and +3 hours after shot, nadir typically occurs between +4 and +6 hours after shot, and usually by +6 to +8 hours after shot, the insulin typically starts to leave the system. ECID - Every Cat Is Different. Depending on your situation, or how aggressively you choose to practice TR, insulin doses for intermediate action insulin can be started at +6 or +8 intervals.

Starting Scale for PZI, ProZinc, Caninsulin/Vetsulin, NPH/Humulin N /Novolin N after Detox Note: Humulin N & Novolin N are the same insulin just different brand names

Criteria to Dose:
1. At least 6 hour since last dose of insulin and
2. BG 150/8.3 or higher, and
3. BG confirmed to be rising, unless 225/12.5 or higher, then dose to maintain overlap.

BG

US(mg/dl) Metric(mmol/L) Dose

151-170.......8.3-9.4...............0.25u
171-185.......9.5-10.2..............0.50u
186-200.....10.3-11.1...............0.75u
201-220......11.2-12.2..............1.00u
221-250.....12.3-13.8..............1.25u
251-290.....13.9-16.1...............1.50u
291-350.....16.2-19.4..............1.75u
351-410......19.5-22.7............2.00u
411-450.....22.8-25.0............2.25u
451-500....25.1-27.8.............2.50u

Bovine Based PZI-Protamine Zinc Insulin (U40, and U100 strengths Available)

Dr. Hodgkins' Tight Regulation protocol was developed for use with bovine based PZI insulin and it remains her insulin preference for cats because its only one amino acid away from a cat's own insulin, and typically has a neutral PH. Bovine based PZI is a very gentle, predictable insulin for felines. Unfortunately over the past 10 years, bovine based PZI isn't as available as it used to be - it is no longer being manufactured in the US. Compounding pharmacies are still making it, however sterility issues as well as potency from batch to batch are concerning many vets which now are not as willing to prescribe compounded insulin types any longer. Many vets are aware of this study which highlights some of the challenges with compounded insulin.

In the US, compounded bovine based PZI is available from both BCP and Stokes Pharmacies, and is available in U40, U50 and U100 strengths. In Canada, Summit compounds bovine based PZI in both U40 and U100 strengths. Compounded versions of PZI are not quite as stable as manufactured insulin and can "poop out" a bit, however, sometimes resting a vial for a bit will help restore potency.

Links to pharmacies compounding bovine based PZI

BCP Vet , Stokes and Summit (In Canada)

When ordering BCP Vet for the first time, there is a free 5ml vial of U100 as well as some other goodies for your vet for placing their first order. Most vets, if asked, will pass this free vial along to you for your cat. The coupon for the free 5ml vial is on their website - just click on the BCP link above, print out the coupon and give it to your vet.

Stoke's no longer compounds U100 (beef based) insulin, however still compounds U40 beef base insulin with an amino acid count only one away from the cat's own.

ProZinc (Salmon based PZI) -U40 strength

ProZinc (protamine zinc recombinant human insulin) was launched in the US in November 2009. It is the only FDA approved insulin for exclusive use in felines. ProZinc is the replacement insulin for Idexx’s PZI Vet. ProZinc is U40 in strength, and is now available in both the US and Canada. It must be purchased either through the vet or online - some of DCC's Affiliate Partners sell ProZinc (as well as syringes, test strip and meters) if you'd like to save some money with exclusive coupon codes, and help DCC's fundraising efforts to help support the site and cat owners in financial need. Pricing of ProZinc will vary depending on your vet’s mark-up. If you live in the US, Pet Meds will price match as long as you provide a competitor’s website when ordering ProZinc by phone. Please see the US Info sticky for links to price match for considerable cost savings.

Most vets in the US will likely prescribe ProZinc as their choice of replacement for Idexx PZI Vet (now discontinued). ProZinc is a recombinant human insulin which is salmon based, and its markers are 4 amino acids away from a cat’s own insulin. ProZinc is formulated exactly like its predecessor PZI Vet, with the exception of salmon based RHdna replacing the 90% bovine/10% porcine pancreatic materials. ProZinc has a PH of 7.1 to 7.4 which is slightly higher than the normal PH of a cat.

Caninsulin/Vetsulin - U40 Strength

Caninsulin was originally created for dogs, hence the name Canin-sul-in. In the US it's called Vetsulin. Caninsulin is the first insulin vets will prescribe for diabetic cats in Europe. Cats in both Canada and the US are now quite often prescribed Caninsulin/Vetsulin at diagnosis. It can be prescribed in pens, or in vials which is preferred as using pens allows only for half or full unit dosing - not the fractional increments we give with TR based on individual cat's needs.

While we're to understand that Vetsulin and Caninsulin are made with the same formula, to date for some reason cats from the UK and Europe have seemed to have better results than cats from North America. In past years, typically a Caninsulin curve was very similar to that of an NPH curve. For some cats, Caninsulin can drop the BG very fast, nadir is relatively short lived, and it leaves the system very quickly resulting in what we can refer to as a "roller coaster" as far as BG curves are concerned. For others, the curve is far more gentle - ECID. While many cats do achieve successful diabetic remission using it, Caninsulin may not be the best insulin for your cat. For this reason, if available in your country, it is recommended if available, to initially purchase the 2.5ml vial of Caninsulin from your vet (rather than a 10ml vial) because if Caninsulin does not provide the desired results within two to three weeks, there will be less waste and expense. Experienced members on forum will be able to guide you through the process of approaching your vet if it appears over time that your cat might prefer another insulin choice.

Caninsulin/Vetsulin is a porcine insulin zinc suspension (PIZ rather than PZI), and is 3-4 amino acids away from a cat's own insulin. It is U40 strength and is generally prescribed with U40 syringes only (or in pen form) by the vet. It is available in both 10ml and 2.5ml vials depending on country. It is uniformly cloudy or milky. It should be stored in the fridge in an upright position to avoid crystals forming around the stopper. Caninsulin is intermediate acting insulin, meaning that onset usually occurs between +2 and +3 hours after shot; nadir is approximately +4 to +6 hours after shot and it usually has left the system by +8 hours after shot at most. Caninsulin typically does not last +12 hours in cats, especially at the start of TR. These approximate times are the norm, every cat is different. Some of DCC' Affiliate Partners carry Caninsulin/Vetsulin which not only might save you some $$, but also helps DCC pay site costs and help members in financial need.

NPH / Humulin N - U100 Strength

NPH (Neutral Protamine Hagedorn) is human recombinant insulin, which comes in U100 strength and must be used with U100 syringes. It is very similar to natural canine insulin and is commonly used for dogs. NPH should appear cloudy in the vial. It is one of the cheapest insulin types on the market (approximately $35.00 per vial depending where you live), and can be left at room temperature for up to 28 days, although refrigeration will increase length of potency. It is stable insulin in that it is not quite as sensitive to knocks and drops as the others. It should not be used after the expiration date. There should be no clumps or white particles in the suspension. If clumps or spots appear, turn the vial end over end a number of times to see if the clumps or spots dissipate. If they do not, the insulin is damaged and should not be used.

NPH is approximately 3 to 4 amino acids away from a cat’s own insulin. It is highly recommended to do 1-hour curves when first starting NPH, beginning at +1 after shot until the insulin starts to leave the system. Onset for NPH occurs between +1 and +2 hours after shot, nadir is approximately +2 to +4 hours after shot, and it leaves the system usually by +6 hours after shot. These are the norm, every cat is different. NPH is insulin that if needed, can be consistently dosed earlier than +6 hours after shot to a rising BG in special circumstances only. Experienced members will help you decide what approach to take with NPH. Even more so than Caninsulin, NPH typically drops the BG fast, has a very short nadir and leaves the system very quickly. It is not abnormal to see drops from a BG in the 400’s(20.0’s) to the 40’s (2.0’s) and back up to the 400’s (20.0’s) within a six hour period.

NPH is not typically the best choice for cats. That said, for some cats it has worked well to achieve diet controlled diabetic remission. NPH is an acceptable "in a pinch" insulin for times when for example, you’ve dropped and shattered your vet-prescribed insulin vial on the floor, the vet clinic is closed for a couple of days, and the drug store is still open. NPH can be used in dire situations where ketones are high and the need to get the BG down quickly is required. Please ask for assistance on forum should you need to switch to NPH in an "urgent" situation.

Long-Lasting (aka Basal) Depot Insulin Types - How They Work in Cats

All long lasting depot insulin types are U100 strength insulin requiring the use of U100 3/10cc syringes with HALF UNIT MARKS. In the human world, depot insulin types are referred to as Basal (background) insulin, designed to keep insulin levels more consistent through the duration of shots. In addition to using Basal insulin, humans frequently also use Bolus (fast acting) insulin to help with food spikes at meal times. Using this Basal/Bolus approach is not very common when it comes to cats, specifically because they tend to use their insulin much faster than humans do, and because we dose insulin earlier on TR than the typical +12 to +24 hour shot cycle humans use.

When practicing TR, depot types of insulin should not as a rule be dosed any sooner than +10 hours after the last shot, and should only be dosed to a confirmed to be rising BG over 150/8.3. Typically onset for depot insulin is 3-4 hours after shot, nadir occurs at +6 to +8 hours after shot with the insulin beginning to leave the system from +8 to +10 hours after shot. That said, once the cats start heal, to they often start to stretch out their durations, nadir can come much later, for many cats in this stage of healing where they are well-regulated, depot insulin types might not even peak until +12, possibly later. When using long lasting insulin, rather than starting with a static dose every 12 hours as is typically prescribed, TR's approach is to use a three rung sliding scale. When compared to an intermediate action insulin, a tighter dosing scale is used with depot insulin types. For many cats we find their insulin scales may have less variance between rungs with only very small adjustments made to doses to deal with later or earlier dosing.

It takes approximately two, if not three (or possibly more) shots (called a cycle) of depot insulin before its really known if the dose is doing what it is supposed to do, reaching ideal numbers at nadir. If ideal BG is not reached after two to three doses, increases are typically be made by either "fat" increases (as little as 0.125u of insulin) or increases of 0.25u increments depending on your testing results. In some cases where it is very clear doses are not working, increasing by 0.5u or more may be called for or tightening up the timing of shots.

Depending on your individual cat's situation, when first starting depot insulin types, it may be recommended to start with some loading doses given +8 hours apart specifically to help build the depot more quickly. Dosing depot insulin types earlier than +10 on a regular basis is typically counter-productive and not recommended as this strategy is not always necessary and depends on your cat's individual needs - ECID. Experienced members on forum can help you determine the correct strategy for your cat when using depot insulin types.

Starting Scale for U100 Depot Insulin after Detox

Criteria to Dose:

1. At least 10 hours since last dose of insulin and
2. BG 150/8.3 or higher, and
3. BG confirmed to be rising, unless 225/12.5 or higher, then dose to maintain overlap.

BG

US ( mg/dl) Metric (mmol/L) Dose

150 - 250........8.3 - 13.9..............0.25u
251 - 400.......14.0 - 22.0.............0.5u
400 +............22.2 +...................0.75u

Lantus / Glargine

Lantus/Glargine is a synthetic human insulin that comes in U100 strength and requires the use of U100 syringes. It is sold in either 10ml vials, or 3ml cartridges or comes in disposable pen form. We recommend purchasing Lantus cartridges as the manufacturers of Lantus state it expires approximately 28 days after opening, so it's likely that even a 3ml vial would not be empty by the time Lantus potentially loses its potency. We recommend storing Lantus in the fridge. Depending on how it has been handled, we have found that Lantus can remain potent for months - certainly long past 28 days.

Lantus is clear, just like water. Should you ever see any crystals in the vial or cartridge, the Lantus has been damaged and should be discarded. If bubbles appear in Lantus, it will start to lose potency. Unlike when filling a syringe with PZI, it is recommended not to draw air into the Lantus syringe to express into the vial when measuring a Lantus dose, nor to back the insulin out of the syringe while it is still in the vial - in an effort to avoid creating air bubbles or affect the crystal based suspension. Draw more than your required Lantus dose into the syringe by at least a half to full unit, remove the syringe from the vial and express the extra insulin onto a paper towel or tissue to avoid creating bubbles.

When giving insulin shots, particularly with Lantus, you want to slowly push the plunger of the syringe in completely and with the syringe still inserted under the skin, slowly count to 10 before removing the needle from the injection site. You may have to hold your cat gently while you wait. Remove the syringe and very gently apply pressure for several seconds. DO NOT RUB THE AREA to avoid damage to the Lantus molecules.

Lantus is long lasting insulin, remaining in the system for 12 hours or more. It typically drops the BG slowly, has an extended nadir, and begins to slowly leave the system after approximately 8 to 10 hours. These are the norm, every cat is different. It is very important to maintain overlap on Lantus – meaning that the remnants of the prior shot are still working to keep the BG as close to normal range as possible, while the next shot is coming to onset. Typically +10 dosing is recommended for Lantus to maintain overlap at the start of TR.

Unfortunately for the most part on forum, there is a challenge to using Lantus. It is a crystal based insulin, released over time once the depot has been refilled, and does not result in the instant gratification that is seen with most of the other insulin types. In humans, Lantus crystals are still present in the system 24 to 48 hours after dose. In cats, due to their much faster metabolisms, its expected the crystals last approximately half that time. Using Lantus requires PATIENCE.

For members in the US, a special offer for Lantus is available on their website, applicable on the first vial purchased.

Levemir/Detemir

Levemir is gaining ground when it comes to use as feline insulin although most vets do not know about it and will typically prescribe Lantus instead. It is a synthetic human insulin which works very similarly to Lantus with a long lasting absorption action; Lev is a depot insulin with a gentle and predictable or peak less curve. Unlike Lantus, Levemir is PH neutral and it is not crystal based. Experienced members on forum can assist to determine if earlier dosing will work better for your cat.

Typically onset for Levemir is 3-4 hours after shot, nadir occurs at +6 to +8 hours after shot with the insulin beginning to leave the system from +8 to +10 hours after shot. We are seeing on forum, cats that have not been well regulated on Lantus or other insulin types can quickly become much better regulated after being switched to Levemir when the right scale is worked towards aggressively. There is some feedback that humans switched from Lantus to Levemir appear to "feel" better after making the switch. For members in the US, there are special savings programs available, or check the US Info sticky for ways to save money on insulin.

Fast Acting (Bolus) Insulin

There are a number of fast acting insulin types which may be of assistance for very hard to control cats, or when ketones have developed and/or a cat needs very aggressive insulin doses to prevent DKA. One of the fast acting insulin types which has been used on forum is known as "NR", the proper name is Novorapid in Canada and Europe. It is known as Novolog in the US. Because TR is an aggressive protocol, most cats on TR do not require fast acting insulin and therefore, we do not provide standard dosing recommendations for fast acting insulin because each case where it might be needed is individual. If you find yourself in the situation where fast acting insulin is required or recommended, please post on Talking TR asking for case-by-case assistance from a member experienced with fast acting insulin, and, you should ALWAYS confer with your vet on how they are best used, what to watch out for and whether or not fast acting insulin is even appropriate for your cat's specific situation.

If you have any questions about any of the information provided in the Insulin and Starting Scales sticky, please post your questions on the Talking TR forum.