From the FDA Drug Label
When switching from another insulin to Insulin Aspart, a different dosage of Insulin Aspart may be needed [see Warnings and Precautions ( 5. 2)] .
The FDA drug label does not answer the question.
From the Research
No dosing changes are typically required when switching between Fiasp and Novolog, as both contain the same active ingredient (insulin aspart) at the same concentration. Patients can generally use the same number of units when transitioning between these two medications. However, it's essential to note that Fiasp has a faster onset of action than Novolog, beginning to work approximately 5-10 minutes after injection compared to Novolog's 10-20 minutes. This difference in onset time means patients should adjust their injection timing relative to meals—Fiasp can be taken right at the start of a meal or up to 20 minutes after starting, while Novolog should ideally be administered 5-10 minutes before eating. When switching, patients should monitor their blood glucose levels more frequently for the first few days to ensure their response to the new insulin formulation is as expected. The difference in action profile is due to the addition of niacinamide (vitamin B3) to Fiasp, which enhances the initial absorption rate of insulin aspart without changing the overall insulin dose required, as seen in a study comparing Fiasp and Novolog in hospitalized patients with type 2 diabetes 1.
Some key points to consider when switching between Fiasp and Novolog include:
- Monitoring blood glucose levels closely after switching to ensure the patient's response to the new insulin is as expected
- Adjusting injection timing relative to meals based on the insulin's onset of action
- Being aware of the potential for differences in hypoglycemia risk, although the overall rate of hypoglycemia may not be significantly different between the two insulins, as shown in a study evaluating the efficacy and safety of fast-acting insulin aspart compared with insulin aspart 2.
- Considering the benefits of Fiasp's faster onset of action, which may improve postprandial glucose control, as demonstrated in a study using a virtual patient simulator to model and predict insulin therapy outcomes 3.
It's also important to note that the choice between Fiasp and Novolog should be based on individual patient needs and preferences, taking into account factors such as lifestyle, meal patterns, and personal preferences, rather than solely on the basis of dosing requirements.