Insulin Safety Center

What Is Insulin?

The human body requires energy to function. We receive energy from the food we eat in the form of protein, fat, and carbohydrates (carbs). Food is then converted into sugar. The sugar has to enter our cells to provide energy. Insulin (IN-su-lin) is a hormone that binds to the sugar to carry it into our cells.

Insulin is like a key that "unlocks the door" to enter the cell. If we did not have insulin in our bodies, the sugar could not "unlock the door" to enter the cell. The sugar would then stay in the blood and would not be used to make energy.

Without insulin, our blood sugar levels would become too high. If this happens consistently, it can lead to serious health problems, including heart disease and damage to the nerves, eyes, and kidneys.

How Is Insulin Produced?

Insulin is normally produced and secreted by the pancreas. In a healthy individual the pancreas will automatically produce and release insulin into the blood stream when the body senses that blood sugar levels are elevated (after a sweet snack or a large meal). People with diabetes either have trouble producing or responding to insulin which affects the regulation of their blood sugar level. They are normally split into two categories: Type 1 and Type 2 diabetes.

Type 1 Diabetes:

Individuals with Type 1 diabetes have lost the ability to produce insulin. Their pancreas no longer produces insulin and they require insulin from outside of their body in order to regulate their blood sugar levels.

Type 2 Diabetes:

Individuals with Type 2 diabetes have the ability to produce insulin, but their body does not respond to it as well as it should. These individuals may find eating a healthy diet and exercising helps control their blood sugar, and in some cases may not need to use insulin.

Are There Any Types of Drugs That Can Interact With or Affect Insulin?

Although insulin does not actually “interact” with any drugs, there are numerous drugs that can have an impact on someone who uses insulin. For instance, certain medications can have an effect on your blood sugar and may contribute to an increased or decreased insulin requirement.

Medicines that can increase your blood sugar (hyperglycemia) include:

•  corticosteroids
•  isoniazid (an anti-fungul medicine)
•  certain lipid-lowering drugs (e.g., niacin)
•  estrogen (a hormone)
•  oral contraceptives (birth control)
•  phenothiazines
•  thyroid replacement therapy (i.e., levothyroxine [Synthroid])

Medicines that can decrease your blood sugar (hypoglycemia) include:

•  oral antidiabetic agents (e.g., Metformin)
•  salicylates (e.g., aspirin)
•  sulfa antibiotics (e.g., Bactrim)
•  certain antidepressants (monoamine oxidase inhibitors)
•  angiotensin-converting-enzyme (ACE) inhibitors (e.g., lisinopril), which are medicines used for blood pressure control
•  angiotensin II receptor blocking agents (e.g., losartan [Cozaar]), which are medicines used in blood pressure control and heart failure

When using insulin, it is especially important that you notify your doctor or pharmacist before you begin taking a new medicine. This includes both prescription and non-prescription medicines. For a detailed list of medicines that can cause hyperglycemia, hypoglycemia, or both, click here. You will be directed to an external website for a PDF of this list.

Does Insulin Have Any Side Effects?

Insulin, like all drugs, may cause some unwanted side effects. These may occur as a reaction to taking too much insulin or as a result of incorrect dosage or interactions with other medicines.

The most common and potentially serious thing to consider with insulin therapy is low blood sugar. Other side effects of insulin may include skin reactions (redness, swelling, itching, or a rash at the site of injection), changes in the distribution of body fat (lipodystrophy), allergic reactions, sodium (salt) retention, weight gain, and general body swelling. These reactions are not common, and the benefit of using insulin outweighs the risk when it comes to blood sugar control.