Skip to main content

Glipizide: 7 things you should know

Medically reviewed by Carmen Pope, BPharm. Last updated on July 26, 2023.

1. How it works

  • Glipizide lowers blood glucose levels and may be used to treat type 2 diabetes.
  • Glipizide works by stimulating insulin secretion from the beta cells of the pancreas. But it can only work if there are still functioning beta cells. This means that glipizide will not work in people with type 1 diabetes. It may also cause other effects related to blood sugar control outside of the pancreas.
  • Glipizide belongs to a class of drugs known as sulfonylureas. It is an antidiabetic agent.

2. Upsides

  • Effective at controlling blood glucose levels in people with type 2 diabetes when used as an adjunct to diet and exercise.
  • Has no detrimental effects on lipid levels.
  • Available as 5mg or 10mg tablets.
  • The recommended starting dose is 5mg, before breakfast. Reduce dosage to 2.5mg before breakfast in seniors and those with liver disease.
  • Generic glipizide is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Nausea, diarrhea, and other gastrointestinal effects have been reported, more often at higher dosages. Transient skin reactions may also occur; glipizide should be discontinued if these persist. Rarely, may cause blood disorders, low sodium levels, and liver disease.
  • May also cause drowsiness and dizziness and affect a person's ability to drive or operate machinery. This effect is usually transient.
  • May cause weight gain. People prescribed glipizide should be counseled on the importance of eating a healthy diet and partaking in exercise.
  • May be associated with an increased risk of death from cardiovascular disease compared with treatment with diet alone or diet plus insulin, based on a study that compared the effects of tolbutamide, another type of sulfonylurea.
  • May occasionally cause severe hypoglycemia. The elderly, malnourished, debilitated, or those with adrenal or pituitary disorders are more at risk. Hypoglycemia is also more likely to occur following severe or prolonged exercise, during sickness, when alcohol is ingested, when food intake is low, or when glipizide is taken with other blood sugar-lowering medication.
  • Not effective in people with type 1 diabetes or for treating serious hyperglycemic events.
  • The blood sugar-lowering effects of glipizide may be enhanced by some other drugs including NSAIDs, antibiotics, sulfonamides, warfarin, probenecid, monoamine oxidase inhibitors, quinolones, and beta-adrenergic blocking agents. Monitoring for hypoglycemia (low blood sugar readings) is recommended.
  • May interact with several other drugs including miconazole, diuretics, oral contraceptives, and corticosteroids.
  • People with kidney or liver disease may experience greater hypoglycemic effects. Monitor and adjust the dose accordingly.
  • May not be suitable for people with glucose-6-phosphate dehydrogenase (G6PD) deficiency.
  • Not recommended for use during pregnancy; insulin should be used instead. May also be excreted into breast milk.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

  • Glipizide may be used in the management of type 2 diabetes to maintain good blood glucose control; however, its effects may wear off with time.

5. Tips

  • Take 30 minutes before a meal for maximum effectiveness.
  • Glipizide is usually taken once a day; however, some people may experience better control if they take it twice a day.
  • Talk to your doctor about what you should do if you become ill as fever, trauma, infection or surgery may disrupt your blood sugar control.
  • The effectiveness of glipizide may decrease over time, either due to an increase in the severity of your diabetes or diminished effectiveness of the drug. Tell your doctor if you think you are not getting the same benefit from glipizide as before.
  • Adhere to all dietary, exercise, and monitoring recommendations that have been recommended by your doctor.
  • Know the signs of hypoglycemia and hyperglycemia and educate your family members and friends as well. Tell them what to do if you show any signs of hypoglycemia or hyperglycemia.
  • The hypoglycemic effect of glipizide may be potentiated by other drugs including those brought from a supermarket or gas station. Always talk to your doctor before starting any other medications.

6. Response and effectiveness

  • Glipizide helps with the release of insulin that occurs after a meal. These effects occur within 30 minutes of an oral dose of glipizide, even though it takes one to three hours for peak plasma concentrations to occur. Glipizide is more effective when administered about 30 minutes before a meal.
  • Blood sugar control persists for up to 24 hours following a single dose, even though levels of glipizide in the blood are barely detectable.
  • Some patients fail to respond initially to glipizide, or gradually lose their responsiveness to glipizide. Glipizide may also be effective in some patients who have failed to respond or ceased responding to other sulfonylureas.
  • Glipizide is well absorbed orally. Absorption may be delayed if administered with a meal rather than 30 minutes before.

7. Interactions

Medicines that interact with glipizide may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with glipizide. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with glipizide include:

  • aspirin and other salicylates
  • anticonvulsants such as phenytoin
  • antidepressants such as tricyclic antidepressants (such as amitriptyline, and nortriptyline) or monoamine oxidase inhibitors (MAOI) (eg, selegiline, isocarboxazid, and phenelzine)
  • antipsychotics, such as thioridazine
  • beta-blockers, such as atenolol, labetalol, and metoprolol, may enhance the hypoglycemic effects
  • calcium channel blockers, such as amlodipine, diltiazem, and nifedipine
  • chloramphenicol may decrease the metabolism of glipizide
  • cimetidine
  • corticosteroids, such as prednisone
  • diuretics, such as HCTZ
  • fibric acid derivatives (eg, fenofibrate, gemfibrozil)
  • fluconazole
  • glucagon-like peptide-1 agonists (eg, semaglutide)
  • isoniazid
  • miconazole
  • NSAIDs, such as diclofenac, ibuprofen, and naproxen
  • probenecid
  • rifampin
  • sulfa medications, such as sulfamethoxazole
  • thiazide and thiazide-like diuretics, such as HCTZ
  • thyroid medications, such as levothyroxine
  • warfarin
  • other medications that are metabolized by CYP2C9, such as amiodarone or metronidazole
  • other medications that affect blood sugar levels or are used for diabetes, such as insulin, glimepiride, or metformin.

Glipizide may also enhance the toxic effects of alcohol, causing flushing.

Note that this list is not all-inclusive and includes only common medications that may interact with glipizide. You should refer to the prescribing information for glipizide for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Glipizide only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: July 26, 2023.