Medications for Diabetes

Published: November 02, 2021
Gabrielle Pierce
By Gabrielle Pierce, PharmD, MBA

Diabetes is a disease in which the body does not make or use insulin correctly, which can lead to unusually high levels of blood sugar. Blood sugar, also called glucose, is the amount of sugar found in a person’s blood. Blood sugar is important because it supplies the cells in your body with energy to function properly. Insulin is a hormone made by the pancreas, which works to maintain blood sugar levels at a healthy range.


What if I am diagnosed with diabetes?

Your doctor will test your blood to see what your blood sugar level is and determine what treatment is right for you. Some people with diabetes may be able to control their blood sugar levels by eating a healthy diet and exercising regularly. Other people may need medication or insulin to manage their blood sugar, in addition to diet and exercise.


Can medications lower my blood sugar?

You may be prescribed medications to treat your diabetes. These medications may be taken by mouth, or they may be injected. Often, it takes multiple medications to achieve the goal blood sugar levels for diabetes. It is normal for the medications or doses to change over time based on other illnesses, activities, or eating patterns to assure the best treatment for you.


Type 2 diabetes is the most common type of diabetes and results from genetics or lifestyle where the insulin produced naturally by your body is not used effectively. Treatment is usually an oral medication to help cells better use the insulin you have or adding insulin as a medication to overcome the resistance. If your blood sugar is high, you may need another injectable medication to effectively treat your diabetes. It is likely that you will be prescribed multiple medications to manage both your blood sugar and other concerns commonly related to diabetes, such as high blood pressure or high cholesterol.


Type 1 diabetes is an autoimmune condition that results in the destruction of the cells in the pancreas that produce insulin. Treatment is aimed at replacing the insulin that is not being produced naturally in the body. For this reason, insulin as a medication is usually the first treatment prescribed for people with type 1 diabetes. Many people with type 1 diabetes use an external insulin pump machine to mimic natural insulin hormone secretion as closely as possible.


As always, it is very important to ask questions and understand how best to take your medications to ensure that they work as well as possible and do not cause side effects.


Why are there different types of insulin medication?

When insulin is given as a medication, the body cannot automatically regulate when to release insulin and how much to release, as it does when the insulin was produced naturally by the body. For that reason, there are several different types of insulin. They are grouped based on how fast and for how long they continue working in the body after injection.


Rapid-acting insulins may start working in as little as 5 minutes and need to be given several times a day. Rapid-acting and short-acting insulins can be given in an insulin pump. Intermediate insulins are usually given twice daily. Long-acting insulins may work for up to 42 hours after injecting and are usually given once daily or less.


Mixed insulin is a combination of two different types of insulin into one medication. Mixed insulins usually contain rapid-acting or short-acting insulin combined with an intermediate-acting or longer-acting insulin. Combinations are used if it is necessary to decrease the number of injections given a day.


Examples of insulins in each category are listed below:


Type of Insulin

When it is Used

Examples of Insulin

Rapid-acting insulin

Before meals and in insulin pumps

Novolog, Humalog, Apidra

Short-acting insulin

Before meals

Humulin, Novolin

Intermediate-acting insulin

Twice a day

Humulin NPH

Long-acting insulin

Once a day

Lantus, Toujeo, Levemir

Mixed insulin with intermediate- or long-acting and rapid- or short-acting

To decrease number of injections

Humulin70/30, Novolin70/30, Humulin50/50, NovoLogMix 70/30, HumalogMix 75/25, HumalogMix 50/50


Why am I on more than one type of insulin?

Blood sugar levels in the body do not always stay the same but change throughout the day depending on what you are eating and how much physical activity you are doing. Physical activity uses up energy and makes blood sugar levels go down; eating a meal or snack provides the body with more glucose for the body to store and can make blood sugar levels go up. Since there are so many changes throughout the day, you may need more than one insulin to help keep your blood sugar at a healthy level in response to your daily activities.


Longer-acting insulins may only be taken once a day and can help maintain the base blood sugar level needed to continuously provide enough sugar for your cells to function. Shorter acting insulins work best if they are taken right before eating a meal; this can prevent your blood sugar from spiking too high as you are eating and can help facilitate converting the sugar into its storage form, glycogen, for later use. For this reason, you may be prescribed a shorter-acting insulin to take right before meals and a longer-acting insulin to be taken once daily to maintain a constant desired blood sugar level.


Since blood sugar levels depend upon your daily activities, your doctor may have to change your insulin dose several times before finding the regimen that works best for you. It is important to ask your pharmacist after a doctor’s appointment if you are not sure whether your dose, timing, or the number of medicines has changed.


Does insulin have any side effects?

It is important to be aware that insulin can cause your blood sugar level to drop too low, which is usually considered less than 70mg/mL. Symptoms you may experience are dizziness, or lightheadedness, feeling tired, feeling warm and sweaty, or feeling more hungry than usual. This can occur if you eat less or increase your physical activity while taking your normal insulin dose, or if your insulin dose is too high for you.


The best way to avoid any negative effects is to test your blood sugar regularly so that you can detect if your blood sugar is getting too high or too low throughout the day. Your healthcare provider can recommend how often you should test your blood sugar daily. You should correct your low blood sugar as quickly as you can by eating or drinking a high sugar or carbohydrate food or taking sugar tablets in the amount recommended by your doctor or pharmacist. 


Questions to ask your pharmacist about insulin

As a medication expert, your pharmacist is a great resource to provide information about diabetes, insulin, and answer any questions you may have about your health. Here are a few questions to consider asking your pharmacist the next time you visit your pharmacy:


  • How should I store my insulin?
  • How long can my insulin stay out of the refrigerator?
  • Why did my insulin dose change?
  • I just had a doctor’s appointment. Do I need to change anything about my insulin dosing?
  • How do I use my insulin pen?
  • Do I need any supplies to use my insulin?
  • When does my insulin pen expire?
  • What should I do if my blood sugar is too high?
  • What do I do if my blood sugar is too low?


For people with diabetes, it is extremely important to carefully monitor your blood sugars and take your medications as prescribed to ensure that your blood sugar levels stay in the goal range most of the time. Doing so will help to prevent the serious long-term complications of diabetes. It is important for you and your health care providers to monitor your sugars, diet, exercise, and overall health.


Be sure to talk to your pharmacist or your doctor if you notice any changes to your normal blood sugar levels. If your blood sugar levels are too high or too low, your pharmacist and doctor may review your medications and decide if any changes need to be made. You can always ask your pharmacist if you have questions about any of your diabetes medications.


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