What is Glipizide?

Published September 25th, 2020 by Chris Riley
Fact Checked by
Chris Riley
Updated Date: Jun 9th, 2021

Diabetes is currently one of the leading causes of death globally. The World Health Organization has mandated a target to halt the rapid increase of diabetes and obesity, two inter-related conditions, by the year 2025. According to recent statistics, approximately 422 million people around the world suffer from the disease. There are mainly two types of diabetes that cause an accumulation of high blood sugar levels that lead to further dangerous health consequences. Type 1 diabetes is an autoimmune condition in which the body lacks the ability to produce insulin that normally processes blood sugar. Type 2 diabetes is characterized by ineffective insulin that cannot function in the right way. Together, these two types of diabetes have a large prevalence within the United States. Why does this disease affect so many people? Diabetes is caused by a combination of genetic and environmental factors, like how much sugar intake your diet has and how much exercise you regularly get. Without treatment, diabetes can be a fatal disease and more than a hundred years ago, the disease had no effective treatment methods available, inevitably leading to death of patients affected by the disease. 

Today, there are many safe and effective diabetes medications available on the market. Some of them, such as insulin, have been around for almost a century helping to stabilize those with a high/low blood sugar level. Other medications used to treat diabetes are relatively new and have been developed for patients that have a medical history of cardiovascular disease or kidney disease for whom standard insulin therapy alone does not work. Diabetes has no cure, so unless a treatment regimen is strictly followed, it can lead to the development of an adverse cardiovascular event like heart attack or stroke, blindness (diabetic retinopathy), nerve damage, heart disease, kidney damage (diabetic nephropathy) and impaired ability of wound healing. 


Glipizide is a well-known diabetes medication used to treat type 2 diabetes diabetics. Although it is one of the leading medications for people with diabetes, people may still be confused on what it is and left asking themselves the question: “How does Glipizide Work?” The medication is also known as the brand names Glucotrol and Glucotrol XL that are manufactured by pharmaceutical giant Pfizer. The medication has been on the market since 1984, so much is known about how it works. Glipizide is considered to be a second-line treatment drug after metformin for the treatment of type 2 diabetes, and it is one of the most commonly prescribed drugs used to treat this condition. Importantly, glipizide is not indicated on its own for the treatment of type 1 diabetes, as it does not work when there is a complete lack of insulin production by the body.

The medication belongs to the class of drugs, called the sulfonylureas, which lower blood sugar. The sulfonylurea drugs work by promoting the release of insulin from the beta-islet cells in the pancreas where this normally happens. The release of more insulin allows blood sugar to be moved into cells to be converted into energy. Since insulin produced in patients with type 2 diabetes is unable to do this on its own, glipizide can compensate for the lack of effective insulin that is produced in the patient, thereby restoring the ability of blood sugar to be processed. Some research has also shown that glipizide may make the body more sensitive to glucose intake by enhancing its ability to respond to elevated blood sugar levels after eating a meal.  

Glipizide belongs to the second-generation of sulfonylureas that were developed to have more potency than first-generation drugs. Compared to other mediations in the same drug family, glipizide is absorbed better and has a faster duration of action. 

It is considered to be effective in treating the early stages of diabetes before there are any signs of pancreatic failure present. This is because the drug relies on the ability of the pancreas to produce insulin. 

Who should not take glipizide 

There are certain conditions that glipizide is not compatible with. If you have ever had the following conditions, inform your doctor before you take glipizide. 

  • Diabetic ketoacidosis- this is a dangerous condition in which there are high levels of ketones in the blood or urine. 
  • Chronic diarrhea or intestinal blockage
  • Glucose-6-phosphate dehydrogenase (G6PD) enzyme deficiency- this is a genetic condition that runs in families. People with this condition who take glipizide could develop hemolytic anemia, or the rapid breakdown of red blood cells. 
  • During the last two weeks of pregnancy- if you are pregnant and have diabetes, it is extremely important to control the condition for the health of the mother and the child. However, glipizide should not be taken by women in their last two weeks of pregnancy. Other diabetes medications are preferred over glipizide during pregnancy, so be sure to discuss this with your doctor if you are pregnant or planning to become pregnant. Breastfeeding women should also check with their doctor before taking glipizide. 

How to take Glipizide 

Glipizide is available as an immediate-release or extended-release oral tablet medication. The regular tablet should be taken 30 minutes before the first meal, once a day. The extended release tablet is taken along with the first meal of the day. The immediate-release tablet dosage is initially started at 2.5 to 5 mg a day and then gradually adjusted according to your body’s response to the medication. A maximum of 40 mg can be taken per day. The extended-release tablet is also started at between 2.5 to 5 mg a day with a maximum dosage of 20 mg allowed. The drug must be used in combination with exercise and dietary changes to get the most benefit from it. Your doctor will recommend the best way for you to take the medication. If you miss a dose, take it as soon as you remember, or if it is close to time for you to take the next dose, skip the missed dose and continue taking glipizide according to your normal schedule. A double dose of glipizide should never be taken or it could lead to severe hypoglycemia. 

Side effects of Glipizide

The most common side effects experienced with taking glipizide include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Constipation
  • Headache
  • Weight gain
  • Dizziness

Another potentially serious side effect of taking glipizide is that it can cause hypoglycemia or low blood sugar. There is a higher risk of this occurring if you take other medications for diabetes that lower blood sugar. Symptoms of hypoglycemia include sweating, weakness, hunger, headache, blurred vision and dizziness. If you experience any of these symptoms while taking glipizide, eat or drink something with sugar in it right away. If you don’t feel better immediately, get emergency medical help.

Drug Interactions of Glipizide 

Glipizide can interact with other drugs, so if you are taking other medications, inform your doctor or pharmacist. Some commonly taken medications can cause low blood sugar or high blood sugar when combined with glipizide. Your doctor can help direct you on how to take other medications along with glipizide to lower the chances of experiencing these effects. 

Examples of commonly used drugs that cause low blood sugar when taken with glipizide include:

  • Non-steroid anti-inflammatory drugs (NSAIDs) like ibuprofen, naproxen and diclofenac
  • Antifungal medications like fluconazole, miconazole, ketoconazole
  • Salicylate containing drugs such as aspirin and salsalate
  • Blood thinners such as warfarin
  • Monoamine oxidase inhibitors 
  • Beta blockers for high blood pressure (metoprolol, atenolol)
  • Sulfacetamide, sulfadiazine, sulfamethoxazole/trimethoprim

Some medications that can cause high blood sugar when taken with glipizide include:

  • Hormones like birth control pills
  • Cholesterol medication like colesevelam
  • Thyroid medication (levothyroxine)
  • Some blood pressure medication like amlodipine

This is not an exhaustive list of drugs that can interfere with the way glipizide works. More information can be found here. 

How much does glipizide cost?

Glipizide is generally an inexpensive medication since generics are readily available. The average list price for brand-name Glucotrol can be as high as $200, but generic versions average around $22. The exact price varies by dosage and pharmacy that you purchase the medication from. The usual cost range of glipizide is between $15 and $45. Most health insurance plans cover the cost of glipizide. 100% of Medicare Part D and Medicare Advantage plans cover glipizide. Typical co-pays with these insurance plans can be as low as $0. However, if you do not have health insurance that includes prescription drug coverage, there are still ways to save on purchasing glipizide. 

Where to buy glipizide and save more

Prescription drug discount cards can be applied to enable additional savings on FDA-approved drugs. The discount card available from USA Rx is a great option that gives you access to purchasing glipizide at an additional savings of about 33% over the lowest price of the drug. With the USA Rx card, glipizide costs just $8.97 at Walmart pharmacies, $11.70 at Walgreens and $12.40 at CVS pharmacies. The card is accepted at more than 90% of pharmacies across the nation, so you are not limited to purchasing glipizide at only these pharmacies. The discount card is completely free, and has no eligibility requirements. You can sign up for the card online and present it at the pharmacy when filling your prescription. Savings will be automatically applied. Since diabetes medications have to be taken regularly, savings will add up quickly, making it easier obtain your medication. 

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