When diabetic patients need to use drugs that cannot be prepared with sodium chloride injection, such as amiodarone and sodium nitroprusside, they often need to add insulin to “mix”. How to calculate the dosage?
1,What should I do if I need sugar in the solvent for diabetic patients?
Fructose, xylitol and other non-glucose solvents can be used as substitutes because their metabolism does not require the participation of insulin and intravenous administration has less impact on blood glucose. However, these solvents are expensive compared to glucose injection and have interactions with many drugs, so they are not the regular solvents recommended by drug instructions.
Therefore, when clinical patients with diabetes must use glucose injection as the drug solvent, they often use regular insulin to “mix” the glucose in the solution.
Here, “blending” is not the chemical neutralization of the two in the infusion bottle, but the use of insulin to regulate glucose metabolism, promote the uptake and utilization of glucose by the liver, bones and adipose tissue, and promote the transformation of glucose into glycogen for storage in the muscle and liver, so as to promote the utilization of glucose by the body and reduce the blood glucose fluctuations caused by the infused glucose.
2,Is it reasonable to add drug-containing glucose solution to insulin intravenous drip?
The author reviewed the relevant literature and found that this usage is also only used more in China and lacks high-quality evidence-based medical evidence. Moreover, with the research in recent years, there are certain disadvantages of insulin added to drug-containing glucose solution in intravenous infusion. First of all, insulin is a peptide hormone with the structure of a hexamer with R6 conformation, which has to be depolymerized into a monomer after entering the human body in order to perform its physiological regulatory function. Because of its special physicochemical properties, insulin is prone to interact with other drugs.
Studies have shown that when insulin is used in combination with certain drugs, it is very likely to produce antigenic substances due to the interaction and cause allergic reactions, which can be life-threatening in serious cases. Similarly, certain drugs cannot be combined with insulin due to their own nature, for example, when infusing drugs such as amiodarone, the instructions clearly prohibit mixing the drip with other drugs to avoid serious adverse reactions.
In addition, the material of the infusion bottle can cause adsorption to insulin.
Relevant studies have shown that the adsorption rate of insulin in plastic infusion bottles is greater than that in glass infusion bottles, and that the adsorption rate of 10% glucose infusion bottles is greater than that of 5% glucose infusion bottles, which will cause instability of insulin concentration in infusion bottles and reduce the actual amount of insulin entering the body.
3,How to correctly apply insulin to glucose in clinical practice?
It is not necessary to add insulin to glucose solution for drugs with poor compatibility, but it is possible to use subcutaneous insulin injection.
On the one hand, it avoids the contraindications of insulin and drugs, on the other hand, due to the pharmacokinetic characteristics of insulin.
Compared with intravenous injection, the effect of subcutaneous injection on glucose conversion appears to be milder and longer-lasting, and the half-life is 2 h and the duration of action reaches 5-7 h after subcutaneous injection, while the half-life is only 5-10 min and the duration of action is only 0.5-1 h after intravenous injection.
Therefore, when combined with drugs that must use glucose as a soluble medium, intravenous glucose solution + subcutaneous insulin injection may be a more ideal dosing regimen at present.
4,How to calculate the amount of insulin to be “mixed”?
It is best to determine the patient’s current blood glucose level first, as the amount of insulin to be added varies with different blood glucose levels. It is especially important to monitor blood glucose in the process of use, and it is necessary to adjust the insulin dosage in order to individualize the medication.