Below is some cut and paste from a different thread, with a bit extra.
No, I was not told about its inflexibility but the reason why I was recommended to start using Tresiba was that it was longer acting than Levemir.
Tresiba is a particularly long lasting basal insulin (typically 40 hrs); so after your first dose on day 1, there is already basal on board as you start day 2. I found 22 units of Levermir daily eventually was refined to 9.5 units Tresiba, which I've recently (gradually) brought to 8.0 units daily with this hot weather. That longevity means its not super critical to take basal at a particular time daily and it also allows you to be a frequent flyer and manage changing time zones more easily.
But, there is a limit to how much you can tinker with Tresiba basal doses. Firstly any changes take time to work - up to 3 days; then several days of leaving alone, to verify the change is working. It's akin to being the Captain of an ocean going container ship, course or speed changes take days to implement (BUT they are all controlled by sophisticated computers, analysing loads of meteorological data for the selected route, ship profile and weight of cargo). In practice the Captain is taking legal and commercial responsibility for a computer programme.
Secondly, it is not realistic to search for optimum 24 hour basal supply with any basal; Levermir gives you 2 bites at that cherry. Tresiba simply can't give you a perfect 24 hr solution. Your insulin needs across the 24 hrs vary a lot. So I've optimised my Tresiba to give me flat, hypo free, nights (when I don't want to be hearing alarms, taking bolus or jelly babies) and I EXPECT to manage my day with bolus doses on a response basis. If that means, on a bad daytime, extra bolus corrections or more aggressive food doses - so be it. Sometimes, not too often, I have to "feed the insulin" because there is too much on board; but I have an armoury of snacks available in many, many diffferent forms of size, volume and varying reponsiveness (GI). If I'm already 'fat and full' then a slurp of lucozade is my choice, or a latte with a small biscuit (or bigger cookie).
Its necessary to experiment, but Libre allows me to safely monitor, understand and respond without
excessive finger pricking. I have my Libre alarm set at 5.6, then I'm alerted when falling, can monitor and snack if necessary. So, personally, now that I've found that wholly acceptable 8 hr night solution, I see no point in daytime basal testing.
This doesn't mean I never change my basal doses. Just sparingly and now only when a succession of nights are no longer satisfactory - either rising or falling.
With a shorter lived basal such as Levermir, I appreciate people can freely tinker with their basal doses, almost on a daily basis. But having moved from Levermir to Tresiba,
which works well for me, I appreciate having one bit of the complexity of D management being out of the daily equations.
I am in the process of having to reduce my carb/insulin ratios for my Novorapid to compensate for the longer basal time.
Yes, my ratios have changed; but to be fair I was not sure I had these optimised anyway and they are something that I understand need monitoring and adjusting periodically as part of the D way of life.
I note what you say about disposable cartridges, and will look into this.
If you change to reusable pens make sure you have at least 2 pens for one type of insulin. A spare reusable pen is a vital safeguard in the unlikely event of a pen failure. I actually have 3 pens, 2x blue for basal and 1x red for rapid. My 'in use' blue basal has a couple of tactile stickers on it to reinforce to me that it's different to my red bolus pen. My 2nd blue pen is a complete reserve, just in case; I know someone else who has 2x blue and 2x red for their own peace of mind.
