Insulin Lantus to 70/30 Conversion is often recommended in individuals with high insulin requirements or sometimes because of the cost. Although each patient’s insulin requirements are different, initial dosing guidelines are discussed here.
Insulin Lantus (Glargine):
Lantus Insulin is a long-acting insulin. It contains Insulin glargine that is used as basal insulin. Basal Insulin usually provides insulin coverage throughout the day. However, basal insulins like glargine (Lantus) primarily target the fasting or premeal blood sugars.
Insulin Glargine is usually administered once daily and can be administered without regard to meals. The levels of Insulin glargine do not spike when administered and hence, the chances of hypoglycemia are very low.
In patients who have high insulin requirements, it can be administered twice daily as well. It is usually given in addition to either short-acting insulin or other diabetes medications.
Lantus insulin can also be administered with sulfonylureas, GLP-1 analogs (Semaglutide, Liraglutide, Dulaglutide), SGLT2 Inhibitors (Empagliflozin, Dapagliflozin, Ertuglflozin, etc), and DPP 4 inhibitors (Sitagliptin, Vildagliptin, and Linagliptin).
Toujeo also contains Insulin glargine, however, the concentration of insulin glargine is three times that of Lantus.
Toujeo insulin is slightly more effective and can be administered an hour or two before or after the exact time.
Insulin 70/30 is available by different brand names. The most commonly used insulin 70/30 contains 70% NPH insulin and 30% Human Regular Insulin.
NPH insulin is an intermediate-acting insulin that has an onset of action between 1 and 2 hours and a duration of action of 12 hours. Thus, NPH insulin provides basal coverage.
While Regular Insulin is short-acting. It has a duration of action of 6 – 8 hours and an onset of action of about 20 to 30 minutes. Humans Regular insulin provides meal coverage to control the spike in blood sugars after a meal.
Insulin 70/30 is also available as insulin analogs. Novomix 30 contains insulin 30% Aspart insulin as rapid-acting insulin and 70% protamine Aspart Insulin.
Like Human Insulin, these insulins are pre-mixed in a ratio of 70/30 (70% intermediate-acting insulin and 30% rapid-acting insulin).
Compared to human Insulin, Novomix 30 is manufactured via recombinant technology. It contains insulin analogs. It has a rapid onset of action of 5 to 15 minutes.
Other pre-mixed insulins that are available are Humalog Mix 25, Humalog Mix 50, and Ryzodeg. Humalog Mix 25 contains 25 percent insulin Lispro and 75 percent protamine Lispro.
Humalog Mix 50 contains 50% insulin Lispro and 50% protamine Lispro. Ryzodeg contains insulin Aspart and Degludec in a 30% and 70% ratio respectively.
How to convert Basal Insulin Toujeo or Lantus to 70/30 insulin or 75/25 Insulin?
It is important to note that initiating basal insulin such as Lantus or Toujeo is very easy. Basal Insulin is initiated in a low dose of 8 to 12 units once daily along with oral diabetes medications.
The dose is then titrated as per the patient’s insulin requirements and glycemic control.
However, switching from basal insulin such as Toujeo or Lantus to 70/30 Insulin is a little tricky. Since insulin dosing is greatly affected by your meal patterns, you may notice fluctuations in your blood glucose during the first week or two of switching from Lantus to 70/30 or converting from any basal insulin to pre-mixed insulin.
Lantus to 70/30 Conversion:
Lantus is once-daily insulin. It is usually given in combination with other antidiabetic medications. When converting from Lantus to 70/30 insulin, the following important points should be kept in mind:
- Lantus is associated with less hypoglycemia compared to 70/30 insulin. It is therefore recommended to reduce the total insulin dose by 20% when switching to 70/30 insulin from Lantus insulin.
- Lantus is usually administered once daily while 70/30 insulin is administered twice daily. Although, the dose of 70/30 insulin depends on the number of meals, generally, the morning dose is higher than the evening dose. Some people administer 2/3rd of the 70/30 dose in the morning and 1/3rd in the evening.
- The concomitant administration of certain anti-diabetic medications is compatible while others are not. It is recommended to discontinue sulfonylureas when switching from Lantus to 70/30 Insulin. SGLT-2 inhibitors, DPP-IV inhibitors, Metformin, GLP-1 analogs, Acarbose, and Pioglitazone can be continued with 70/30 Insulin.
Examples of Lantus to 70/30 Conversion:
A person on metformin 1000 mg twice daily and Lantus Insulin 30 units at bedtime wants to switch to 70/30 insulin. How can we adjust his dose?
- Reduce the Insulin dose by 20%. In this case, 20% of 30 units is 6 units. The total dose of 70/30 insulin that is required by this person is 24 units (30 – 6 = 24).
- Next, split the 24 units into 1/3rd and 2/3rd insulin. This is equal to 8 units and 16 units.
- Administer 16 units before breakfast and 8 units before dinner. Insulin 70/30 should be administered 30 minutes before meals.
- Metformin is continued along with insulin.
People who are on twice-daily meals may need dose adjustments. Half or more units may be administered with the first meal and half or fewer units may be administered with the second meal.
20% dose reduction may not be advisable for people who have uncontrolled blood glucose with Glargine.
Furthermore, if a person is on insulin secretagogues such as sulfonylurea (Glyburide, Gliclazide, or Glimepiride) should discontinue these medicines. Such patients may need to increase the insulin 70/30 dose by 20% rather than reducing it.
The same rules should be followed when converting from Lantus to Humalog Mix 25 or Humalog Mix 50 Insulin. However, Humalog Mix 50 is the preferred insulin for patients who take twice-a-day meals.
Lantus to Ryzodeg Conversion:
The main advantage of Lantus to Ryzodeg conversion is the post-meal glucose control in people using Ryzodeg insulin.
Lantus insulin controls only basal or premeal glucose spikes. Ryzodeg contains rapid-acting insulin, Aspart, and Degludec Insulin. Aspart Insulin is rapid-acting with a short duration of action.
It provides meal coverage only. Degludec (Tresiba) is ultra-long-acting insulin that, like Lantus Insulin, provides basal coverage.
Individuals who take two small meals and one heavy meal may experience post-meal hyperglycemia. Most people either dinner or lunch as one heavy meal and two small meals.
After the heavy meal, their blood sugars spike. Such patients may best benefit from Ryzodeg 70/30 insulin administered once daily with the major meal of the day.
When converting from Lantus to Ryzodeg, reduce the dose by 20%. Administer the total Ryzodeg dose once daily before the heavy meal of the day.
Example of Lantus to Ryzodeg Conversion:
If you are using Lantus Insulin 30 units after dinner and notice blood glucose spikes after dinner, you can switch to Ryzodeg Insulin. First, reduce the total dose by 20%. This will be equal to 24 units. Administer the dose (24 units) before dinner.
Ryzodeg can be switched to any time of the day. It can be administered before breakfast or before lunch as well depending on the post-meal glucose spike.
Ryzodeg is one of the best options for people who fast. In Ramadan, Muslims usually have one major meal of the day after breaking the fast.
There is a rapid rise in blood glucose after breaking the fast in the evening. Ryzodeg can provide a basal cover as well as control the blood sugar spikes after the evening meal.
When co-administering Ryzodeg before dinner with Short or rapid-acting Insulin, the dose of rapid and short-acting insulin should be given only before breakfast and lunch.
However, when short or rapid-acting insulin is required for meal coverage along with Lantus Insulin, they should be administered before each meal of the day i.e. three times a day.
What are the advantages of Lantus to 70/30 Conversion:
70/30 Insulin especially, Humulin 70/30 (Mixtard 70/30), is much cheaper than Lantus, Toujeo, Xultophy, Soliqua, and Ryzodeg Insulin.
70/30 Insulin controls postmeal hyperglycemia and provides basal coverage as well, while Lantus and Toujeo provide only basal coverage. Thus, postmeal blood glucose may spike in people using Lantus or Toujeo.
What are the disadvantages of Lantus to 70/30 Conversion:
Lantus is administered once daily (rarely twice daily) while 70/30 Insulin is administered twice daily. People with needle phobia may not opt for twice-daily insulin administration.
There is an increased risk of hypoglycemia with 70/30 insulin compared to Lantus (Glargine) Insulin [Ref]. Furthermore, blood glucose fluctuation is greatest with 70/30 compared to Glargine Insulin.