Insulin

INSULIN, produced in β cells of pancreatic islets, is produced from proinsulin. It is released in pulses every 15-30 minutes. The strongest release stimulus is an increase in blood glucose above 5.6 mmol / L.

The main biological functions of insulin include: improvement of glucose and amino acid uptake by most tissues, in muscle and liver cells, it increases glycogenesis and prevents glycolysis, and also accelerates the oxidative breakdown of glucose, increases fat production, as well as the uptake of free fatty acids through the synthesis of triglycerides. Interestingly, insulin is included on the list of prohibited substances of the World Anti-Doping Agency, because it is an anabolic hormone.

During the use of insulin, many side effects may occur in the form of lipodystrophy, i.e. loss of adipose tissue, insulin allergy, insulin resistance due to the occurrence of antibodies to insulin or a decrease in the sensitivity of tissues to insulin, therefore it is necessary to be careful in its administration and to follow the recommendations with great care doctor.

Currently, all insulin used is obtained by recombinant DNA technology. We distinguish between unmodified (human) insulins and modified (analog) insulins created by genetic engineering in order to obtain preparations with specific pharmacokinetic properties, i.e. especially with a rapid onset of action, short or long duration of action.

Insulin medicinal products, duration of action, use:
1. Preprandial insulin.

They are characterized by a quick onset of action from 3-15 minutes. They should be given just before, during or just after a meal. They do not require an interval between insulin injections and a meal, which reduces the risk of hypoglycaemia. This group includes insulin:

Lispro (Humalog, Liprolog, Lispro Sanofi)
Aspart (NovoRapid)
Glulisine (Apidra)
Short-acting human insulin. They are not modified, they are obtained by biosynthetic methods. They are also called regular insulins and this is where the letter “R” comes from in the trade names of some preparations (Actrapid, Humulin R, Gensulin R, Polhumin R, Insuman Rapid). They should be administered about 15-30 minutes before a meal. Patients should remember to snack between main meals to avoid hypoglycaemia.

2. Insulins with an intermediate duration of action.

• Isophane insulin (NPH) (Polhumin N, Insulatard, Insuman Basal, Gensulin N). Thanks to the combination of insulin molecules with protamine and zinc, it was possible to extend the duration of action to 5-8 hours. Their onset of action is estimated at about 2 hours, while they should be taken about 15-30 minutes before a meal.

3. Long-acting and very long-acting insulins (basal insulins).

Insulin glarigine medicinal products are acidic. Following subcutaneous administration under physiological conditions, acidic insulin glarigin is micro-precipitated. It is slowly released from the microcrystals formed within 24 hours. On the other hand, insulin detemir, thanks to its combination with myristyl acid, increased the binding of insulin with blood proteins, which led to the possibly slow release.

Glargine (Lantus, Abasalar, Toujeo). They should be given once a day at the same time, regardless of the meal. It is characterized by long (over 24 hours) peakless operation.
Detemir (Levemir) Individual dosage 1-2 times a day. The duration of action is up to 24 hours, depending on the dose.
Degludec (Tresiba). The onset of action is observed after about 2 hours. They should be given once a day at the same time, regardless of the meal.

4. Insulin mixtures.

They are in the form of suspensions and the contents of the ampoule are cloudy, so they should be mixed before use. Individual products in this group consist of fast-acting insulin and long-acting insulin. This allows different performance profiles to be provided. Regardless of the type of mixture, they are characterized by two peaks of action. There are two types of mixtures:

human mixtures (Gensulin M30, M40, M50, Humulin M3, Mixtard 30,40,50, Polhumin Mix-3 and Mix-5, Insuman Comb 25). They should be administered about 15-30 minutes before a meal. The symbol M30 means that the mixture consists of 30% soluble short-acting insulin and 70% isophane insulin,
analog mixes (Humalog Mix 25 and 50, NovoMix 30 and 50). Their onset of action is very quick> 15 minutes. Before use, they should be mixed together and administered just before, during or just after a meal.

STORAGE OF INSULIN

The stock of insulin should be stored in the refrigerator (2-8 ° C), preferably on the door. After first opening, the insulin pen is stored at room temperature.

MEDICAL DEVICES FOR DIABETES – tips:

Glucometers and lancets
a broken meter can be replaced at the pharmacy,
in cases where the patient does not have a meter and has received 2 packets of strips on the prescription, the pharmacist may give the patient the meter (for free). In general, however, patients receive their glucometers from the attending physician,
good operation of the meter can be checked by control fluids,
each puncture should be made with a new needle. Needle number 3 is tried the first time,
needles = lancets should be disposed of in the red package.

Blood Collection:

It should come from the side of the finger as there are fewer nerve endings there (compared to the fingertip). Alternative sites may include the calf, palm, thumb or little finger. Always wash your hands in warm water before proceeding, as this increases blood flow, and then dry them.

Insulins and pens
short-acting insulins – given before a meal,
long-acting insulins – The insulins inside the ampoule have a glass ball to mix the insulin. It is used at night – in order to obtain a constant glycemia, sometimes also in the morning,
mixed insulins – a dose of fast-acting insulin + long-acting insulin. A number from 10 to 40 represents the% of rapid-acting insulin content in the ampoule,
after opening the package [putting it into injection], store the insulin at room temperature for 28 days (sometimes up to 6 weeks) – cold insulin injection is painful for the patient.

Types of pens:

disposable – the ampoule is attached to the pen, use a new needle each time. Before serving, set 1-2 units and press e.g. over a sink to fill the needle with insulin,
reusable – you can change insulin ampoules.
Bioton is the main company producing pens in Poland,
Novonordisk – has a needle cap on the ampoule, thanks to which a better seal is obtained,

Place of insulin injection:

subcutaneously
fast-acting – stomach or arm – absorbs the fastest,
long-acting or mixed – thighs, buttocks
“abdominal” administration – cover the navel with your hand and insulin may be given into the surrounding area

Choosing a needle for insulin administration:

Customized to body build
Obese and normal body – 8 mm “yellow”
Very slim people and children – 5-6 mm “blue”

The needles are disposable as insulin may crystallize or there may be tissue clogging the needle. In addition, the needle, once used, is much less sharp, which causes pain and increases the risk of infection.

people with a lot of fat tissue – insert the pen directly,
people with a small amount of adipose tissue should catch fat, e.g. on the abdomen, so as not to stick into the muscle tissue. We drive in at an angle of 90 ° or 45 °,
after injecting insulin, wait 8 seconds for the entire amount of insulin to drain.

Literature:

• Mutschler, G. Geisslinger, H. K. Kroemer, P. Ruth, Mutschler Pharmacology and Toxicology,
• Szczeklik, P. Gajewsk, Interna Szczeklik,
• Pharmacodynamics, a textbook for Students of Pharmacy
• Characteristics of medicinal products.