Insulin (Parenteral)

Overview

Insulin is a hormone that your body uses to turn food into energy. Its secondary use is storing energy that can then be used sometime in the future. Once we eat, insulin extracts sugar from our blood and puts it into our body's cells which can then make protein, fat, and sugar. If we then require more energy between the meals that we eat, insulin helps us to use this stored fat, protein, and sugar. This same process works either if we make our own insulin or if we need to receive it through regular injections.

If a patient suffers from diabetes mellitus, then they have a condition whereby their body is either unable to properly use the insulin it makes or is simply unable to make enough insulin. If you don't have enough insulin then glucose cannot be transferred into the body's cells. As such, cells don't get glucose and can't function properly.

In order to work effectively, the amount of insulin used in our bodies must be equally balanced with the exercise we do and the food we eat. By changing either your exercise routine or the amount you eat, and not adjusting your insulin doses, your blood glucose levels can either rise too high or drop too low. In order to access most insulin, a prescription is not necessarily required. However, there are a variety of different insulin brands that are suited better to certain patients. Your doctor will need to determine your exact insulin need and then give you the right information to help control your diabetes.

The insulin itself will either come from pork or beef pancreas glands. It is also possible that you may use human insulin. This human insulin is similar to that found being made by a functioning pancreas, but is actually made by methods known as recombinant or semi-synthetic DNA. Insulin must always be injected and not swallowed. If it is swallowed, it is simply destroyed by the stomach.

Conditions treated

  • Diabetes Mellitus

Type of medication

  • Injection

Side effects

Alongside the intended effects of this medication, it can produce some unwanted side effects. Not all of these may be present, however, if they do occur, you may need to seek medical attention.

You should consult with your healthcare professional right away if you suffer from any of the following side effects whilst taking insulin:

More common

  • Unconsciousness

You should consult with your healthcare professional right away if you suffer from the side effects listed below whilst taking insulin:

  • Low blood sugar

Rare

  • Depressed skin at the place of injection

Not all of the side effects listed above have been reported for each of these medications, but they have been reported for at least one of them. Each of the insulins is similar, so any of the side effects listed above could occur with any of these medications.

You could also suffer from other side effects not listed above. You should seek advice from your doctor or healthcare professional if you notice anything unusual or strange.

You can report all side effects to the FDA on 1-800-FDA-1088.

Dosage

The final dose of medications in this class will be different for each patient. The following information is an average of each dose of medications. If your dose is not the same, you should not change it unless your doctor has specifically told you to do so.

The amount of medicine that you take depends on a number of factors. This includes your weight, age, and height, and other medical conditions you suffer from including corresponding medications you take to treat them. The strength of the medication will also be a factor, including the number of doses you are required to take each day, the time allowed between doses and your reaction to the first dose.

For regular insulin (R) ' Human buffered, crystalline zinc, and human regular insulins for injection dosage form:

For treating diabetes mellitus:

Teenagers and adults:

The final dose will be determined by your doctor as it's based on your blood sugar. The medication is injected under the skin 15 or 30 minutes before meals and/or a snack at bedtime. Your doctor may also want you to use more than one variation of insulin.

Children:

The final dose is based on your body weight and blood sugar and will be determined by your doctor.

For isophane insulin (NPH) - Human isophane and Isophane insulins for injection dosage form:

For treating diabetes mellitus:

Teenagers and adults:

The final dose will be determined by your doctor as it's based on your blood sugar. The medication is injected under the skin 30 to 60 minutes before a meal and/or snack at bedtime. Your doctor may also require you to use more than one variation of insulin.

Children:

The final dose will be based on your body weight and blood sugar and will be determined by a doctor.

For isophane insulin human/insulin human (NPH/R) - Human regular/human isophane insulin for injection dosage form:

For treating diabetes mellitus:

Teenagers and adults:

The final dose will be determined by your doctor and is based on your blood sugar. This medication is injected under the skin 15 to 30 minutes prior to breakfast. You may require a dose at bedtime or before another meal. Your doctor may also require you to use more than one type of insulin.

Children:

The final dose is based on your body weight and blood sugar and will be determined by your doctor.

For insulin zinc (L)'Human Lente and Lente insulins for injection dosage form:

For treating diabetes mellitus:

Teenagers and adults:

The final dose will be determined by your doctor as it's based on your blood sugar. This medication is injected under the skin 30 to 60 minutes prior to breakfast. You may require another dose at bedtime or before another meal. Your doctor may also require you to use more than one variation of insulin.

Children:

The final dose is based on your body weight and blood sugar and will be determined by your doctor.

For insulin zinc extended (U)' Human ultralente and Ultralente insulins for injection dosage form:

For treating diabetes mellitus:

Teenagers and adults: The final dose of this medication will be determined by your doctor as it's based on your blood sugar. It is injected under the skin 30 to 60 minutes prior to a meal or snack at bedtime. Your doctor may require you to use various types of insulin.

Children:

The final dose is based on your body weight and blood sugar and must be determined by your doctor.

For (S) Semilente insulin (prompt insulin zinc) for injection dosage form:

For treating diabetes mellitus:

Teenagers and adults:

The final dose will be determined by your doctor or diabetes specialist as it's based on blood sugar. Insulin is injected under the skin around 30 to 60 minutes before you eat breakfast. You may also need a dose 30 minutes before another meal or a snack at bedtime. Your doctor may require you to use two insulin's at the one time.

Children:

The final dose of this medication will be based on your body weight and blood sugar. It will, therefore, be determined by your doctor.

Proper use

Ensure you get the type (pork and beef, human or pork) and the strength of insulin that your doctor ordered for you. You can find that keeping an insulin label with you is helpful when purchasing insulin supplies.

The concentration of insulin is measured in USP Insulin Human Units and USP Insulin Units and is usually expressed as U-100 insulin. Insulin doses are injected and measured with specially marked insulin syringes. The specific syringe is chosen based on the insulin dose to make measuring the dose easier to read. This will help you measure your dose correctly. These syringes come in 3 different sizes: ½ cc measuring up to 50 USP Units of insulin, 3/10 cubic centimeters (cc) measuring up to 30 USP Units of insulin, and 1 cc measuring up to 100 USP Units of insulin.

It's important to follow instructions given by your doctor about selecting and rotating injection sites on your body.

There are several important steps that will assist you in successfully preparing your insulin injection. To draw the insulin up into the syringe correctly, you should follow these guidelines:

  • Wash your hands with water and soap

Don't use insulin if it looks grainy or lumpy, seems unusually thick, sticks to the bottle, or looks slightly discolored. Don't use the insulin if the bottle looks frosted or if it contains crystals. Regular insulin (short-acting) can only be used if it is colorless and clear.

Don't remove the rubber stopper but remove the colored protective cap that is in the bottle.

Use an alcohol swab to wipe the top of the bottle.

Remove the needle cover from the insulin syringe.

How to prepare your insulin dose if you are using one type of insulin:

  • Pull back on the plunger to draw air into the syringe. The amount of air will be equal to your insulin dose.

Check your dose by holding the syringe with the scale at eye level to check that the proper dose is withdrawn and to look for air bubbles.

If air bubbles appear, then tap gently on the measuring scale of the syringe. This will move them to the top and you can push the insulin slowly up the bottle and draw your dose again.

Withdraw more solution from the bottle if your dose measures too low in the syringe. Put some back into the bottle if there is too much insulin in the syringe. Then look at your dose again.

Remove your needle from the bottle and re-cover the needle.

Preparing your insulin doses when you are using two different variations of insulin:

When you are mixing another type of insulin with regular insulin, you need to always draw the regular insulin into the syringe first. When you mix two types of insulin that are not regular insulin, you shouldn't worry about which enters the syringe first as this isn't necessary.

After you determine a certain order for drawing up your insulin, you should repeat that same order each time.

Some mixtures of insulins need to be injected right away. Others can stay stable for a long time which means that you can wait before you inject the insulin. Consult with your healthcare professional to find out which type of insulin you have.

Pull back the plunger to draw air into the syringe. The amount of air in the syringe will be equal to the part of the dose that you will be taking from the 1st bottle. Inject the air into bottle number one. Don't draw the insulin yet.

Next, draw into the syringe an amount of air that is equal to the dose that you are taking from bottle number two. Inject the air into the second bottle.

Return to the first bottle of the combination. Draw the first insulin dose of the combination into the syringe with the dose at zero.

Ensure it is the correct dose by holding the syringe with the scale at eye level to check that the proper dose is withdrawn and to look for air bubbles. If air bubbles appear, remove them by tapping gently on the measuring scale of the syringe. This will bring them closer to the top to remove.

If the first part of the dose measured is too low in the syringe, you can withdraw more insulin from the bottle. If there is too much solution in your syringe, then return some to the bottle. Then double check the dose again.

Next, without moving the plunger, put the needle into the second bottle of insulin and withdraw the required dose. You can withdraw a little bit more insulin from the second bottle than needed as it will help you correct the second dose easier when you remove the air bubbles.

Double check that you have withdrawn the proper dose. Your syringe will now contain two types of insulin. Don't squirt any extra solution from the syringe back into the bottle as this may alter the insulin in the bottle.

Dispose of any extra insulin in the syringe.

If you are unsure whether you have correctly created the solution, then throw the dose away and start the steps again. Don't return any of the solutions back into the bottle. The same procedure can be repeated with the same syringe.

If you have previously prepared your mixture then gently turn the filled syringe back and forth to mix the insulins together before you inject. Don't shake the syringe.

How to inject your insulin dose:

Once you've prepared your syringe and selected an area of your body to inject into, you're ready to inject into the fat area of skin.

Where the injection is to be given, clean with an alcohol swab or with water and soap, and then leave to dry.

Pinch a large area of skin and hold it firmly. Then with your other hand, hold the syringe up and push the needle straight into the pinched-up skin at a 45-degree angle for a child or 90-degree angle for an adult. Ensure that the needle is fully inserted. It's not necessary to draw back on the syringe each time to look for blood.

Push the plunger the full way, using less than five seconds to inject the dose. Let go of your skin and hold an alcohol swab near the needle and then pull the needle out of your skin.

Hold the swab against the injection area for several seconds. Don't rub.

If you overweight or thin, you may be given special instructions for giving yourself insulin injections.

How to use special injection devices:

It's important to follow any information that comes alongside your insulin and the specific device you are using to assist with injection. This will ensure proper insulin dosing and proper use. If you need more information about this, seek advice from your healthcare professional.

For patients using an automatic injector:

After you have drawn the dose, place the disposable syringe inside the automatic injector. Then press a button on the device quickly and it plunges the needle into the skin, releasing the insulin dose quickly.

For those patients using an insulin pump:

You should use buffered regular human insulin when it is available as this is is the recommended insulin for insulin pumps. However, when this isn't available, non-buffered regular insulin can be used too.

The pump consists of a computerized device that is worn in the chest or waist area, and a tube that has a needle attached to the end of it. The pump allows you to receive insulin continuously. You can calculate insulin doses to be received via a button at meal times.

It's important to follow the directions given by the pump manufacturer on how to load the pump reservoir and/or syringe. If you don't load these correctly, you may not obtain the correct amount of insulin.

You should check the infusion site dressing and tubing as often as is recommended by your diabetes specialist to ensure the insulin pump is working correctly.

For patients using disposable syringes:

Manufacturers of disposable syringes recommend that they are only used once, due to the sterility of a reused syringe. However, some patients prefer to reuse a syringe. Most insulins have chemicals added that prevent them from growing the bacteria that are typically found on the skin. However, your syringe should be thrown away when the needle has been bent, becomes dull, or has come into contact with any surface other than the swabbed and cleaned area of skin. If you plan to reuse a syringe, your needle must be recapped each time. Consult with your healthcare professional to find out more about the best way to reuse syringes.

For patients using an insulin pen device (disposable needles and cartridge):

Alter the dose by rotating the head of the pen. Place the pen next to your skin and press down on the plunger to inject the medication. Some pen devices can only inject specific doses of insulin with each injection. Injection amounts can differ for different pen devices. To ensure you receive the correct dose, you may have to count the number of times you press down on the plunger. These devices also use special cartridges of regular insulin (R), isophane insulin (NPH), or a mixture of the two.

For patients using nondisposable syringes (metal needle and glass syringe):

This style of syringe and needles can be used repeatedly if they are sterilized after each time they are used. You should obtain an instruction sheet that shows you how to do this. If you require further information about this, speak with your diabetes specialist or healthcare professional.

For patients using a device without needles, known as a spray injector

The dose of this insulin is measured by rotating part of the device. You draw insulin up into the spray device via an insulin bottle and then forcefully press a button that then sprays your required insulin dose onto the skin. This technique involves a larger area of skin than you would require for an insulin injection in the traditional form.

Laws in some states require that used insulin needles and syringes are to be destroyed. Exercise caution when you bend, recap, or break a needle, because these actions increase your chance of a needle-stick injury. It's best to place used needles and syringes in a disposable container that is puncture-resistant or to use a needle-clipping device. If the plunger is taken out of the barrel and broken in half when you dispose of a syringe, this reduces the chance of a syringe being reused by someone else.

Use this medication only as directed by a doctor. Don't use less or more insulin than your doctor has recommended - to do so could increase your risk of serious side effects.

Your doctor will give you specific instructions about exercise, diet, how to test your blood sugar levels, and how to adjust insulin doses when you are ill.

Diet: The number of daily calories in the meal plan should be adjusted by a registered dietitian or your doctor to help you reach and maintain a healthy body weight. In addition, snacks and regular meals should be arranged to meet the energy needs of your body at various times of the day. It's extremely important that you carefully follow your meal plan.

Exercise:

Seek advice from your doctor on the best type of exercise to do and when to do it each day. You should also find out how much exercise you should be doing each day.

Blood tests:

This is the best indicator as to whether you are controlling your diabetes properly. By taking regular blood sugar tests you can allow both you and your doctor to adjust your insulin doses as required.

Changes in dose:

Your doctor may alter the first dose of the day. This change could change your blood sugar later in the day or change the amount of insulin required in another period of the day. That is why your doctor should be made aware if your dose changes, even if only temporary.

On sick days:

When you become sick with a fever, cold, or the flu, you will need to continue to take your insulin even if you feel too ill. This is especially true if you have vomiting, nausea, or diarrhea. Infections typically increase your insulin requirements. You should seek specific advice from your diabetes specialist. Continue to take your insulin as failure to do so could increase your risk of high blood sugar and DKA. However, if you have trouble eating solid foods then drink non-diet drinks, fruit juices, or clear soups, or eat small amounts of bland food. A doctor or dietitian can provide you with a list of foods and the amounts to use for sick days. Test your blood sugar regularly (at least every 3 hours while you are awake) and test for ketones. If they are present, call your doctor right away. If you have prolonged or severe vomiting, then seek medical attention right away.

Interactions

It is possible that insulin will interact with other drugs you are currently taking. In many cases, your doctor will try and avoid such interactions, but in other cases, they can't be avoided and are necessary for your treatment. Either way, you should inform your doctor of all drugs you are currently taking, both prescription and nonprescription. Your doctor can then decide what is the best way to proceed with your treatment. They may decide to change one or both of the interacting drugs, or may simply alter the doses you receive of one or both. Below is a list of drugs with which it is usually not recommended you take insulin. However, if it is required that you take both, then your doctor may alter the dose of one or both medicines.

  • Gatifloxacin

As well as interacting with other drugs, it is possible that insulin will interact with certain parts of your dietary intake. Your doctor will likely require for you to inform them of what you typically eat, drink, and smoke. They may need to advise you of certain adjustments to your dietary intake in order to avoid such interactions. For example, you may need to decrease how much or how frequently you smoke tobacco or drink alcohol. It is not recommended that you take insulin at the same time as the following. If it is unavoidable, your doctor may need to alter one or both of the amounts of insulin or the interacting substance you take.

  • Ethanol

Finally, insulin may interact with other medical problems you are suffering from. You should inform your doctor of your complete medical history. In particular, be clear in highlighting any of the following if they apply to you.

  • A severe infection

Warnings

Before prescribing you with insulin, or indeed a particular brand of insulin, your doctor will need to fully understand the extent of your condition and your medical history. As a part of this process, they will need to be made aware of any allergies you suffer from. This includes allergies to animals, dyes, foods, or preservatives.

It has been found that children are more sensitive to the effects of insulin than older patients, especially during times that sexual changes occur, like during puberty. In such cases, they are more prone to low blood sugars. With regards to teenagers, the use of insulin is more similar to that of adults. However, doses may need to be lower after puberty and higher during it.

Studies in geriatric patients have found that the use of insulin in geriatric patients is similar to other age groups. However, it is possible that the initial signs of high or low blood sugars may be missed or may be missing altogether. As such, this increases the chance of lower blood sugars in general. As well as this, some geriatric patients may have other medical problems, like those with their vision. This can make it harder to both measure and inject the necessary medicine. It may be that they require special equipment or extra training.

If you become pregnant, then the amount of insulin you need will change both during and after. In order to ensure the full health of your baby, you will need to control your blood sugar levels closely. Poor control can increase the chances of birth defects, them having too much weight, or them having low or high blood sugar levels. If you are pregnant or plan to become pregnant, you should inform your doctor. Similarly, if you become pregnant at any time, inform your doctor right away.

It has been found that insulin does not pass through breast milk. As such, if you are breastfeeding then it won't harm your infant. However, be aware that many women find they need less insulin than before whilst they are breastfeeding. You will need to closely test your blood sugar for several months to know when your insulin doses need to be changed.

Under no circumstances should you ever share insulin cartridges or pens with other patients. It is not safe for you to use the same pen amongst more than one person. This can lead to the transmission of HIV, hepatitis, or other viruses that are blood-borne.

Your doctor will need to meet you at regular appointments throughout the year in order to check your condition and make any necessary adjustments to your treatment. This is even more important during the first few weeks of starting to use insulin.

Here is some additional guidance your health team will require you to follow alongside properly using insulin.

  • Alcohol. Drinking alcohol can cause your blood sugar levels to drop lower. You should discuss this in depth with your healthcare team.

In case an emergency does occur, you should prepare yourself by taking the following precautions.

  • Always carry a medical ID neck chain or bracelet. You can carry an ID card in your purse or wallet as well which explains your condition and lists all the necessary medicines you take.

If you take too much insulin, you could experience hypoglycemia. Below you can find the symptoms of low blood sugar levels. You should treat these as soon as possible or else you are at risk of passing out. Be aware that the exact symptoms you experience may be different from others. You should try and learn quickly which ones apply to you.

  • Cold sweats

You may experience low blood sugars for any of the following reasons

  • Drinking a significant amount of alcohol

If you do experience these symptoms of low blood sugar, you should consume some form of fast-acting insulin. This should help to stop your symptoms getting any worse. Good sources of such sugar include:

  • Sugar cubes (six one-half inch size)

As well as this:

  • If you don't have a scheduled dose for another hour, you can eat a light snack as well like half a sandwich, cheese and crackers, or have an 8-ounce glass full of milk.

Hyperglycemia (high blood sugars) is another problem that can occur with poor diabetes management. If you do experience high blood sugars at all, you should tell your health team right away. Failure to treat high blood sugar can lead to severe hyperglycemia which then leads to ketoacidosis (a diabetic coma) and eventual death. Below are the symptoms of hyperglycemia. Be aware that they can appear more slowly than the symptoms of low blood sugar.

  • Tiredness

Below are the symptoms of severe high blood sugar levels (meaning ketoacidosis and an eventual diabetic coma). Be aware these may require hospitalization.

  • Fruit-like breath odor

It is possible you will experience these symptoms if you:

  • Do not exercise as much as you usually do

You should know what to do if you do have high blood sugars. In order to avoid it, your doctor may advise you alter your meal plan or change your insulin doses. Before they are allowed to progress more severely, high blood sugar symptoms must be treated. You should consult with your healthcare professional or doctor regularly to ensure you are properly controlling your blood sugars. Your doctor may need to discuss the following points with you:

  • If your blood sugars are above 240 mg/dL, then you should not exercise and report this to your doctor straight away.

Storage

Insulin should be stored in a refrigerator. It cannot be frozen.

Unopened bottles of insulin should be refrigerated until they are required for use and can be used until the expiration date that is printed on the label. You should never freeze insulin as this will render it useless. To avoid stinging at the injection site, you should remove the insulin from the refrigerator and allow it to reach room temperature before you inject it.

An insulin bottle that is in use can be kept at room temperature for up to one month. After that, it should be thrown away.

To prevent the risk of the crystal forming in the needle and blocking it, you should store prefilled syringes in the refrigerator with the needle pointing up.

Don't expose insulin to sunlight or extremely hot temperatures. Extreme heat can cause insulin to become less effective quickly.

Summary

If you suffer from diabetes mellitus, then insulin is a vital medicine you must take in order to control your blood sugars and avoid unwanted health complications. However, taking insulin is not straightforward, and you will require proper training from your healthcare team on how to use it. Also, there is not just one type of insulin, and you may require more than one in order to properly manage your condition. You will also likely be supplied with a diet plan and any changes you should make to your lifestyle. By following these properly, you have the best chances of properly managing your condition.

Failure to properly control your blood sugars can lead to severe hypoglycemia. With the effective training of both you and your close family members, you should be able to know what to do under such circumstances. If you do experience any of the more severe side effects or symptoms listed above, you should contact your doctor immediately. Similarly, if you have any other questions about your diabetes, then you should contact your doctor immediately.