NPH insulins can be mixed with short-acting regular insulin, the only exception being zinc insulins (Herold 2022).
When mixing, please note:
- mixing should take place immediately before injection of the syringe; injection should be carried out within a maximum period of 2 min thereafter
- Never store insulin as a mixture
-
Insulin glargine or insulin detemir cannot be mixed with other insulins (Kasper 2015)
Pharmacodynamics
In an insulin mixture, some of the normal insulin binds to the NPH insulin. Once the mixture is injected, this binding reverses (Hirsch 2020).
Mixing the insulins can result in a change in the insulin absorption profile: absorption is shortened, for example, by mixing Lispro with NPH (Kasper 2015).
The short-acting normal insulins mimic physiological insulin secretion during meals (Kasper 2015).
Insulin mixtures with a low proportion of normal insulin have a longer effect than mixtures with a high proportion of normal insulin (Mehnert 2003).
Indication
Insulin mixtures are used in conventional insulin therapy (Herold 2022), especially in type 2 diabetics with constant food intake at precisely defined times (Hirsch 2020).
Only a fixed insulin mixture should be used in the following patients:
- Patients with reduced vision that cannot be corrected.
- Patients with impaired fine motor skills of the fingers (Mehnert 2003).
Type 1 diabetics are treated with insulin mixtures in the context of conventional insulin therapy only in exceptional cases. These are patients:
- who, due to cognitive impairments, illness or age, are unable to undergo another form of treatment, the so-called "intensified insulin therapy".
- who decide against intensified insulin therapy after having been informed in detail about the benefits and risks of the treatment
- Who show significant adherence problems in long-term care (Bahrmann 2018).
Dosage and mode of administration
Insulin requirements:
The daily insulin requirement of a healthy person is 0.67 I. E. / kg KW / d = approximately 40 I. E. (Dellas 2018). S. a. Insulin
In obese patients, the requirement is usually higher. These patients require approximately 2.0 I. E. / kg KW / d (Greten 2005).
Adverse effects
- Hyperinsulinemia between meals
-
Hypoglycemia (Waldhäusl 2004)
-
Dawn phenomenon (predominantly initiated by an insulin dose that is too low in the evening [Mehnert 2003])
Contraindication
Relative contraindications for insulin mixtures:
- severe insulin allergies (although these are a rarity)
- unreliable insulin injections e.g. drug abuse
- dietary treatable type 2 diabetes
- more difficult practical implementation, e.g., in blind, elderly patients living alone (Paumgartner 2013)
Absolute contraindications to treatment with insulins:
- Hypoglycemia
- Insulinoma (Flake 2021)
Drug interactions
- Weakening of the effect of insulin by:
- Isonicotinic hydrazide
- Sympathomimetics
- Corticosteroids
- Phenothiazines
- oral contraceptives
- Heparin
- nicotinic acid and its derivatives
- phenytoin
- tricyclic antidepressants
- saluretics (Flake 2021)
- Effect enhancement of insulin by:
- ASA
- Cyclophosphamide
- Methyldopa
- Tetracyclines
- Fenfluramine
- Clofibrate and its derivatives
- Alpha blockers (Flake 2021)
Preparations
The ready-to-use preparations include:
(Herold 2022)