Lyumjev vs. Fiasp.

@ljk200 I’m reading a book called Mayo Clinic The Essential Diabetes Book by M. Regina Castro, M.D. (3rd Edition). It is available through Mayo Clinic Press. It contains a fantastic chart of all the types of insulin (in one of the appendices).

Both of these insulins are considered “Very fast-acting”.

They have the same “Onset of action” Within 5 minutes.

The same “Maximum effect” About 1 hour.

The same “Duration” 3 - 4 hours.

The same “How it’s typically used” Inject at the start of a meal or within 20 minutes after starting a meal.

The same “Notes” Absorbed promptly and very short-acting; often used in addition to intermediate- or long- acting insulin.

I tried to recreate this portion of the chart for you. I don’t have personal experience with either insulin. I’m 50+ years diabetic, age 67 and I use an insulin pump with insulin Lispro (brand name Humalog). From what I understand from this chart the two insulins should be equivalent or at least comparable. I applaud your researching this. Have you asked your doc why s/he is
“unenthusiastic” about this? Another favorite Dr. question of mine is to make it personal by asking your doc if this were them what would s/he do. Will you get back to Mayo Clinic Connect to report what you decide?

Hi Cheryl. Thanks for the info. The study I read about Lyumjev was published in Diabetes Obesity Metabolism, May 2022. My doc eventually wrote a script for Lyumjev, and I am going to give it a try as a replacement for Fiasp.
Laurence

I’m using fiasp (insulin aspart) and used once lyumjev (insulin lispro) as well. I got severe allergic reaction to lyumjev. I assume it’s because I’ve been only using novo Nordisk insulin (insulin aspart) from the start (novolog then fiasp). When anyone who is used to insulin aspart switch to insulin lispro or the reverse they can have allergic reaction. If you used insulin lispro (humalog or lyumjev)before and no side effects then you can try it. I’ll stick to fiasp as there’s no alternative option for me. The effectiveness period is not that different. Fiasp is very similar to the speed of natural human insulin.

I am insulin dependent type 2. I just switched from Fiasp to Lyumjev a few days ago. I am now adjusting my bolus insulin to carb ration from what it was when I took Fiasp (x units per 18 carbs to same amount of insulin per 20 carbs). I find that Lyumjev drops me very quickly within a half hour of injecting, so quickly that I feel the same way as I do when I'm heading for a real low. Thirty minutes seems to be peak for me. Lyumjev also keeps me at the low end, BG 75 - 89, after 5 hours and until I eat again. Strangely, Lyumjev seems to be active in my system for a longer time span than Fiasp.
I can't say if what I'm experiencing is permanent, I'm having an idiosyncratic reaction or, if my body is simply getting adjusted to a new formulation of insulin. I also have to keep in mind that with type 2 I'm still producing a small amount of insulin.

For @haforn and @tedbruce in regards to different types of insulin, if you scroll up in this thread to comments in the spring of 2024 some of us were talking about a book that is applicable to this discussion. The book is available from Mayo Clinic Press. It is called The Essential Diabetes Book by M. Regina Castro, M.D. In one of the appendices is a chart of all the types of insulins. I printed a hard copy of it to refer to. It shows an easy summary of things like duration, time of action onset, peak ….. You might find it to be a useful reference tool if you and your provider are considering making any changes to your insulin regimen.

I appreciate your experience with Fiasp vs Lyumjev . I switched to Lyumjev in the hopes of getting a faster effect. Thus far, I have not noticed much difference between the effective rates of the two brands.

Thanks Cheryl, I appreciate your suggestion. I also found that Fiasp had to be titrated over time. It began to take more Fiasp to produce the desired effect. In listening to others, its clear that there are a number of different responses to the same insulin. As I stated, being type 2 adds an additional variable because I make a small amount of my own insulin. The only thing that has been 100% on target (no surprises and very consistent) has been my basal insulin.

I am insulin dependent type 2. I recently switched my bolus insulin from Fiasp to Lyumjev. There are a few things that have occurred with the change that I don't fully understand. Just before stopping Fiasp, I ended up requiring one unit per 16 grams of carbs with the fiasp. With the Lyumjev I only require 1 unit per 20 grams of carbs. This makes no sense to me. Has anyone else found a marked dose difference between Fiasp and Lyumjev? The second issue is more an annoyance than a problem, Lyumjev drops my BG so quickly and dramatically that my CGM sounds off and tells me that I'm in 60's with a straight down arrow. My Glucometer tells a different story, stable in the upper 80's to mid nineties. The last difference between Fiasp and Lyumjev is that 5 hours post injection the Lyumjev drops to a BG in the 80's. I then vacillate between the mid 70's and upper 80's until I have my next meal. Has anyone (type 2) had a similar experience with Lyumjev? This last issue sounds like Lyumjev is placing me closer to what a person without diabetes would experience, but it also means that I have to be very cautious when I decide to exercise or do any physical exertion.

I found my print version of the appendix that I referred to in my comment on January 9th. According to that Fiasp and Lyumjev are equivalent:

Very fast-acting
Onset of action within 5 minutes
Maximum effect about 1 hour
Duration 3-4 hours

BUT what I was reminded of and learned more about at an appointment with my endocrinologist yesterday is that people may respond differently to the same treatment (insulin, meds …..etc.) not only that BUT the same individual may respond differently at different times throughout the day! This really hit home after we spent a fair amount of time tweaking and adjusting target blood sugar ranges, correction factors, insulin : carbohydrate ratios, boluses, basals for time periods 24/7.
Not only is it true that there is no such thing as one size fits all. I found out that one size doesn’t always work for me either (throughout the day and night).