Glipizide dosage, forms, and strengths

Glipizide (brand names: Glucotrol and Glucotrol XL) is a medication used to treat Type 2 diabetes mellitus. It belongs to a drug class called sulfonylureas and controls high blood sugar levels in adults by stimulating the secretion of insulin from the pancreas and decreasing glucose from the liver. It works best when combined with diet, exercise, and other healthy lifestyle choices. A patient’s healthcare provider will monitor their blood sugar levels and A1C (also referred to as glycated hemoglobin, glycosylated hemoglobin, or HbA1C) regularly during treatment to determine glipizide dosage and adjustments to medication.

Glipizide is usually taken once a day in the morning, either 30 minutes before breakfast or with breakfast. It may be paired with other antidiabetic medications, like metformin. Common side effects include low blood sugar, diarrhea or constipation, stomach discomfort, nervousness, gas, headaches, drowsiness, and tremors. Serious side effects are less common and include hypoglycemia (very low blood sugar), low white blood cells, anemia, low blood platelets, hepatitis, jaundice, low blood sodium, and severe allergic reaction. Glipizide is not a treatment option for patients with Type 1 diabetes.

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Glipizide forms and strengths

Glipizide is available in tablet form and comes in immediate-release and extended-release options. 

• Extended-release tablets: 2.5 mg, 5 mg, 10 mg

• Immediate-release tablets: 5 mg, 10 mg

Glipizide dosage for adults

Glipizide is approved to treat Type 2 diabetes in adults. The dosage instructions vary depending on the patient’s age, weight, and blood glucose levels. For extended-release tablets, the initial dose is 5 mg by mouth once daily with a meal. The maximum dose should not exceed 20 mg by mouth per day. The starting dose for immediate-release tablets is 5 mg by mouth once daily, 30 minutes before breakfast. The maximum dose should not exceed 40 mg by mouth per day.

A healthcare provider will gradually increase the dose of glipizide in increments between 2.5 mg and 5 mg until the patient’s blood sugar level is within the target range. It’s important to keep an accurate record of blood sugar readings between appointments to help providers determine the proper maintenance dose of glipizide. Most patients take glipizide once daily, but some patients benefit from taking it on a twice-daily basis.

Glipizide dosage for children

Glipizide is currently not approved for children younger than 18.

Glipizide dosage restrictions

There are some dosage restrictions and contraindications to be aware of before beginning treatment with glipizide.

Patients with hepatic impairment should begin by taking 2.5 mg of immediate-release glipizide by mouth per day. Extended-release tablets have not been studied in those who have liver disease.

Glipizide does not have a defined dose for patients with renal disease. It’s suggested to decrease the dose by 50% for patients with a GFR above 50 mL/min.

Use caution in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency, an inherited enzyme deficiency. Taking glipizide increases the risk of hemolytic anemia. Other treatment options should be considered.

Patients older than 65 and patients with adrenal or pituitary insufficiency may be more sensitive to glipizide. For this reason, a healthcare provider may recommend starting at a lower dose of 2.5 mg by mouth per day. Doses will be gradually increased until blood sugar levels are within an acceptable range, as determined by a patient’s healthcare team.

Patients with Type 1 diabetes or diabetic ketoacidosis should not take glipizide, as insulin is the proper treatment in these cases.

Avoid taking this medication if hypersensitivity occurs or has occurred while taking this drug in the past.

Glipizide dosage for pets

Glipizide is sometimes used to treat diabetes in cats. Veterinarians may prescribe 5 mg or 10 mg tablets. The medication helps the pancreas release insulin and increase tissue sensitivity so that smaller amounts of insulin have a larger impact. Glipizide is often used as a trial medication before advancing to insulin injections or in cases where the cat is sensitive to insulin injections.

Cats taking glipizide may experience side effects including:

• Low blood sugar

• Loss of appetite

• Nausea

• Elevated liver enzymes

• Pancreatic destruction (in rare cases)

Oral medications aren’t efficient in stimulating insulin production in dogs, therefore glipizide is not used to treat diabetes in dogs.

How to take glipizide

• Glipizide is taken by mouth. 

• The immediate-release glipizide tablets should be taken 30 minutes before eating. 

• Extended-release tablets should be taken with a meal. 

• Follow a healthcare professional’s guidance in checking blood sugar levels at home during treatment. 

• Talk to a healthcare professional about what to do in case of very high or very low blood sugar readings.

• Never skip or change dosing without consulting a healthcare provider.

• Take medicine as directed. A patient’s dose may need to be changed several times to find what works best for them.

• Swallow the extended-release tablet whole. Do not crush, break, or chew it.

• Read and follow the

  that come with this medicine.

• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Glipizide dosage FAQs

Glipizide vs. glipizide XL: What’s the difference in doses?

The starting dose for immediate-release glipizide is 5 mg per day, with a maximum dose of 40 mg per day. The starting dose for glipizide extended-release is 5 mg per day, with a maximum dose of 20 mg per day. A healthcare provider will determine which form of glipizide is right for the patient.

The prescribed dose varies by person and is determined in response to their blood sugar levels after taking glipizide. Healthcare providers will work with patients to find the dose that works best for them. Patients will monitor their blood sugar levels at home to assess how the medication affects their blood sugar. Their healthcare provider will increase their dose gradually until their blood sugar is within an acceptable range.

How long does it take glipizide to work?

Glipizide works quickly. It’s important to take daily doses as directed, based on the form prescribed. Take immediate-release tablets 30 minutes before a meal to reduce blood sugar levels after eating. Take extended-release tablets at the same time as breakfast. If a patient takes glipizide but doesn’t eat, as directed, their blood sugar may drop and cause symptoms of hypoglycemia.

How long does glipizide stay in your system?

The half-life of a drug is the amount of time it takes for the concentration of that specific drug to reduce to half of the original dose taken. Glipizide has a half-life of between two and seven hours. The time glipizide stays in a patient’s system varies from person to person and depends on several factors, including how fast their body metabolizes medications.

What happens if I miss a dose of glipizide?

Patients should take the missed dose of glipizide as soon as they remember if they’re getting ready to eat a meal. If they are skipping the meal, they should also skip the dose of glipizide to ensure their blood sugar doesn’t drop too low. Never take multiple doses together. If a patient is unsure, they should check their blood sugar level at home and consult their healthcare provider for advice.

How long can you take glipizide?

Glipizide is a long-term medication to control chronic hyperglycemia in patients with Type 2 diabetes. Take the medication as directed by a healthcare provider.

How do I stop taking glipizide?

Never stop a medication without talking to a healthcare provider. Failing to take glipizide as directed can cause a dangerous increase in blood sugar levels or other adverse reactions.

If a healthcare provider has advised the patient to discontinue glipizide, they may recommend tapering off the medication slowly. To do this, they will likely reduce the dose by half and continue to evaluate the patient’s blood sugar levels over a period of time.

What is the maximum dosage for glipizide?

The maximum dosage of immediate-release glipizide is 40 mg per day. The maximum dosage of glipizide ER is 20 mg per day.

Can you overdose on glipizide?

Taking too much glipizide can cause a life-threatening drop in blood sugar (hypoglycemia). If an overdose is suspected, seek help at the nearest emergency medical facility or call 911.

Signs of severe hypoglycemia include weakness, excessive drowsiness, tremors, trouble focusing, abnormal sweating, dizziness, blurred vision, confusion, rapid heartbeat, and seizures.

What interacts with glipizide?

Drug interactions are possible. There are several medications that can alter the effects of glipizide. Some of these medications include:

• Salicylates, like aspirin

• Anticonvulsants

• Antidepressants

• Antipsychotics

• Beta blockers

• Blood thinners, like warfarin

• Colesevelam

• Calcium channel-blocking drugs

• Diuretics, like chlorothiazide and hydrochlorothiazide

• Antifungals, like fluconazole and miconazole

• Hormones

• MAO inhibitors

• NSAIDs

• Thyroid medications

• Medications that alter blood sugar levels

• Some antibiotics, like isoniazid

Discuss any current prescription drugs, herbal supplements, and over-the-counter medications with a healthcare provider before taking glipizide.

What happens when you mix glipizide and alcohol?

Drinking alcohol while taking glipizide increases the risk of hypoglycemia and puts patients at increased risk for side effects, including:

• Flushing

• Rapid heartbeat

• Headache

• Gastrointestinal discomfort

• Confusion

• Chest discomfort

Avoid drinking with this medication.

Is it safe to take glipizide during pregnancy?

There is limited human data to determine whether glipizide is safe to take during pregnancy. The FDA classifies glipizide as a pregnancy risk category C drug, meaning that animal studies have shown potential risk to the fetus but there is no known risk based on limited human data. 

Patients who are pregnant or planning to become pregnant while taking glipizide should notify a healthcare provider. If an alternative drug is not an option, it is recommended to discontinue the medication at least two weeks before delivery to prevent hypoglycemia in the infant at birth.

Is glipizide safe while breastfeeding?

The effects of glipizide on lactation and on the infant are unknown. Glipizide may pass to the baby through breast milk. Breastfeeding mothers should discuss the safety of this medication with their healthcare provider before beginning treatment.

Related resources for glipizide dosages:

• Adult dosing

• Glipizide

• Glucotrol

• Glipizide for cats

• Glyburide and glipizide, second-generation oral sulfonylurea hypoglycemic agents