Diabetes and Insulin Treatments – Side Effects Explained by a Pharmacist

Most insulin products share these common side effects:

• Injection Site Irritation
• Low blood sugar
• Weight gain
• Low potassium

Diabetes is one of the most common chronic conditions in the general population. It is estimated that over 30 million people in the United States have been diagnosed with diabetes.

That number would likely continue to rise, as more than 80 million adults have pre-diabetes. Pre-diabetes is the early stage of abnormal sugar control, where lifestyle changes can still be enacted to prevent or delay the progression to type 2 diabetes.

What is alarming is that up to 90% of individuals with pre-diabetes do not know that they have it.

It is another reminder that an annual preventive exam is highly recommended, so that the providers can diagnose early and implement an effective treatment plan. Type 1 and type 2 diabetes are the most common types of diabetes. Both types involve the body’s inability to regulate the process of turning food into energy.

After digestion, food is normally broken down into smaller sugar molecules, called glucose, that are released into the bloodstream. When the pancreas detects a surge in blood glucose, it releases insulin to help drive glucose into the cells to use as energy. When the pancreas cannot produce as much insulin, or that the cells become resistant to insulin, too much sugar molecules would remain in the bloodstream. As time goes on, this could cause serious complications, including heart disease, kidney disease, vision loss, and neuropathy.

Type 1 diabetes usually occurs in the younger stage, when people lose the ability to produce insulin. Type 2 diabetes most often occurs in the adult ages and is a progressive disease.

People with type 1 diabetes remain on insulin regimen for life. With type 2 diabetes, if diagnosed early and remain well-controlled, people may not progress to complete loss of natural insulin production.

Whichever the case, insulin products have become more popular as diabetes treatment in recent years. There are many different products available, with different therapeutic profiles. 

Long-acting insulins, also called basal insulins, are those that are usually injected as once daily. Commonly prescribed ones include Lantus, Levemir, and Tresiba. Intermediate-acting insulins, such as Humulin N and Novolin N, can be given as once or twice daily. The long and intermediate-acting insulins are given to mimic the natural body’s insulin production.

On the other hand, short-acting and rapid-acting insulins are given around mealtimes. Common short-acting (or regular) insulins include Humulin R and Novolin R. Common brands of rapid-acting insulins include Humalog and Novolog.

Beside the mentioned insulin products, premixed insulins, where two different insulin products are combined together, are also available. 

It is important to inject insulin as directed by the prescriber and stay adherent to the regimen. However, it is important to watch for certain side effects and know when to discuss with your providers. 

Most insulin products share these common side effects:

• Injection Site Irritation
• Low blood sugar
• Weight gain
• Low potassium

Injection Site Irritation

Some people may notice some redness, swelling, or itchiness in the area where insulin has been injected. Though these slight irritation reactions should go away after awhile, let the doctor or pharmacist know if they persist. It could be a sign that the method of injection needs some adjustment.

An irritated reaction should not be mistaken as an allergy reaction to insulin. Although less commonly occurred, an allergic reaction usually involves more severe responses from the body. Such responses may include a rash that covers a large area of the body, trouble breathing, low blood pressure, racing heartbeat, or sweating. If you notice any of these symptoms, seek immediate medical care.

It is also important to remember that rotating the injection site is recommended to avoid scarring of the tissue. Scarring can lead to altered absorption of insulin and make it less effective in controlling your blood glucose. 

Low blood sugar

Hypoglycemia, or low blood sugar, is a common side effect, especially in the elderly population. This usually occurs when the insulin lowers the blood glucose level too much and too quickly. Some noticeable symptoms include sweating, hunger, irritability, dizziness, and shakiness. In the more severe case, it can lead to loss of consciousness, which needs immediate medical attention.

When noticing these signs, it is always important to check the blood sugar right away. If the glucose reading shows a level of 70 mg/dL or less, the “rule of 15” is recommended to help bring the glucose level upward. 

It simply means that you should consume 15 grams of carbohydrate, wait around 15 minutes, and then recheck your blood sugar level. If your blood glucose is still low, repeat the cycle of 15 until the number is at goal. The following items contain about 15 grams of carbohydrate, which you could store in your house and keep them handy:

• Half a cup of orange juice or regular soda (not diet or sugar-free)
• 3-4 glucose tablets
• 6-8 LifeSavers
• 1 tablespoon of sugar or 5 small sugar cubes
• 1 tablespoon of honey or syrup

It is always good to let your prescriber know if you experience low blood sugar and how often these episodes occur. The dose may need some adjustment, or a different insulin may work better for you.

Weight gain

In some people, insulin products may increase the body’s hunger response. This could lead to increased appetite and craving, which may result in noticeable weight gain.

If weight gain is a concern for you, discuss with your prescriber at the next office visit. An alternative insulin product may be appropriate. Your prescriber may also refer you to a dietician to develop meal planning methods and work toward weight loss goal.

Low Potassium

Hypokalemia, or low blood potassium level, may occur in some patients. Besides helping move glucose into cells, insulin also helps move potassium into cells. A low blood potassium level can lead to problems with heart function.

Although not a common side effect, this may be a concern in patients who already take medications that can lower potassium level, such as diuretics (fluid or water pill). It is important to let your prescriber know your full medication list, and report to your provider if you notice any strange feeling with your heartbeats. 

It is always good to be aware of the common side effects of insulin products and when to let your provider know when you notice any of the mentioned symptoms. 

Diabetes is a progressive disease, it is important to take your insulin regimens as prescribed. By remaining adherent to therapy and maintaining your diabetes under control, you can stay away from serious complications like heart and kidney diseases.