Micronase (Glyburide): Discontinued Brand, Generic Cost and How It Compares With Glipizide

Micronase was Pfizer's brand of glyburide, an older sulfonylurea tablet for type 2 diabetes. The brand is no longer sold in the US: the FDA's Drugs@FDA database lists every Micronase strength as discontinued. Generic glyburide is still widely available and costs US pharmacies only a few cents a tablet. So when a pharmacy says it cannot fill "Micronase", the usual answer is the generic, not a hunt for the old brand.

This guide explains what happened to Micronase and its sister brands, the difference between regular and micronized glyburide (they are not interchangeable milligram for milligram), what glyburide costs compared with glipizide and glimepiride, and why US and international guidance now treat glyburide more cautiously than other options, especially in older adults and in pregnancy. We sell glyburide-containing and glimepiride tablets, so we have a commercial interest. Every figure comes from the FDA labels, trials and price data listed under Sources. Do not change or stop a diabetes medicine without your doctor.

The short answer

Micronase (NDA 017498, Pfizer) is discontinued in the US, and Drugs@FDA records a determination that at least its 1.25 mg and 5 mg strengths were not withdrawn for safety or effectiveness reasons. Generic glyburide 1.25 mg, 2.5 mg and 5 mg tablets are the direct replacement, with the same starting dose of 2.5 to 5 mg a day with breakfast and a maximum of 20 mg a day. Micronized glyburide (the old Glynase PresTab) uses smaller doses and is not bioequivalent, so anyone switching between the two forms has to be re-titrated. At US pharmacy cost, generic glyburide 5 mg is about $0.07 a tablet. The main drawback is low blood sugar: in a meta-analysis of 21 trials, glyburide carried about 52% more risk of hypoglycemia than other secretagogues. The 2023 Beers Criteria say that if a sulfonylurea is used in an older adult, short-acting glipizide should be chosen over glyburide or glimepiride.

What Micronase was

Detail	Micronase
Active ingredient	Glyburide (called glibenclamide outside the US)
Drug class	Sulfonylurea: makes the pancreas release more insulin
Application	NDA 017498, Pfizer
Strengths	1.25 mg, 2.5 mg and 5 mg tablets
US status	All strengths discontinued (Drugs@FDA)
Replacement	Generic glyburide tablets, same strengths

Glyburide is used with diet and exercise in adults with type 2 diabetes. It does not work in type 1 diabetes, because it depends on the pancreas still making insulin.

Is Micronase still available?

Not as a brand. The status of the glyburide brands in Drugs@FDA (via openFDA, checked October 2026) is:

Brand	What it is	Application	Status
Micronase	Glyburide 1.25, 2.5, 5 mg	NDA 017498 (Pfizer)	Discontinued
DiaBeta	Glyburide 1.25, 2.5, 5 mg	NDA 017532 (Sanofi)	Listed as prescription
Glynase PresTab	Micronized glyburide 1.5, 3, 4.5, 6 mg	NDA 020051 (Pfizer)	Discontinued
Glucovance	Glyburide with metformin	NDA 021178 (Bristol Myers Squibb)	Discontinued

For the 1.25 mg and 5 mg strengths of Micronase, and for every Glucovance strength, Drugs@FDA carries a note that a Federal Register determination found the product "was not discontinued or withdrawn for safety or effectiveness reasons." That matters because it lets generic versions keep referring to the brand. Brands are often dropped for commercial reasons once cheap generics dominate, and that is the pattern here.

One naming trap: in India, "Glynase XL" is a brand of glipizide extended-release. US Glynase was micronized glyburide. Same name, different drug, so always check the active ingredient on the pack.

Why you can still get glyburide easily

Generic glyburide is common in the US. In the Medicaid NADAC pharmacy cost file for the week of 21 October 2026, there were 12 separate product listings (NDCs) priced for glyburide 5 mg tablets and 10 for 2.5 mg tablets. Micronized glyburide is much thinner on the ground: 2 listings for 3 mg and 1 for 6 mg. Generic glyburide with metformin (the Glucovance combination) had 5 listings each at 2.5/500 mg and 5/500 mg.

Regular vs micronized glyburide: not the same dose

Micronized glyburide uses smaller drug particles that are absorbed differently. The labels are explicit that the two forms cannot be swapped milligram for milligram.

Form	Strengths	Usual starting dose	If sensitive to hypoglycemia	Maximum daily dose
Glyburide (non-micronized, the Micronase and DiaBeta form)	1.25, 2.5, 5 mg	2.5 to 5 mg a day with breakfast	1.25 mg daily	20 mg
Micronized glyburide (the Glynase form)	1.5, 3, 6 mg	1.5 to 3 mg a day	0.75 mg daily	12 mg

The non-micronized label states that micronized glyburide 3 mg tablets "are not bioequivalent" to non-micronized 5 mg tablets and that "patients should be retitrated when transferred." The micronized label adds that a maintenance dose of 3 mg micronized gives roughly the same blood sugar control as 5 mg of the non-micronized form. In practice, if you have an old Micronase prescription and the pharmacy offers micronized glyburide, the dose on the label will need to change. Ask the pharmacist to confirm which form you are getting.

Dose increases should be no more than 2.5 mg (non-micronized) or 1.5 mg (micronized) at weekly intervals. Doses above 10 mg a day of the non-micronized form may work better split into two doses, according to the label.

How glyburide compares with glipizide and glimepiride

All three are sulfonylureas sold as cheap generics in the US. Their labelled doses differ:

Drug	Usual starting dose	Maximum	Older adults (label)
Glyburide	2.5 to 5 mg a day with breakfast	20 mg a day	Conservative dosing; renal function to be assessed
Glipizide (immediate release)	5 mg before breakfast	15 mg once daily; 40 mg total a day (Glucotrol label)	May start at 2.5 mg
Glimepiride	1 or 2 mg once daily	8 mg once daily	Start at 1 mg

The bigger difference is in how often they cause low blood sugar, covered next. For how glimepiride compares with first-line metformin, see our guide to metformin vs glimepiride.

The main problem with glyburide: low blood sugar

Every sulfonylurea can cause hypoglycemia. The glyburide label says: "All sulfonylureas including glyburide are capable of producing severe hypoglycemia." It also warns that kidney or liver problems can raise glyburide levels and increase the risk of serious reactions, and that hypoglycemia may be hard to recognise in older people and in people taking beta blockers.

The question is whether glyburide is worse than the alternatives. A 2007 meta-analysis in Diabetes Care pooled 21 randomised trials.

Outcome, glyburide vs comparator	Relative risk	95% CI
At least one hypoglycemia episode vs other secretagogues	1.52	1.21 to 1.92
At least one hypoglycemia episode vs other sulfonylureas	1.83	1.35 to 2.49
Cardiovascular events	0.84	0.56 to 1.26
Death	0.87	0.70 to 1.07

So glyburide carried about 52% more risk of hypoglycemia than other secretagogues and 83% more than other sulfonylureas, while heart events and deaths were not significantly different.

Severe hypoglycemia in routine care

Trials can understate rare, severe events, so real-world data help. A four-year population-based study in one region of Germany counted every episode of severe hypoglycemia needing emergency treatment in people taking glimepiride or glyburide (glibenclamide).

Drug	Severe episodes	Person-years	Rate per 1,000 person-years
Glimepiride	6	6,976	0.86
Glyburide	38	6,789	5.6

The people who had these episodes were old (mean age 79) and 62% had impaired kidney function. This was an observational study, so other differences between patients may have played a part, but it points the same way as the trial meta-analysis.

What the Beers Criteria say for older adults

The American Geriatrics Society Beers Criteria list medicines that are potentially inappropriate in people aged 65 and over. The 2023 update widened the sulfonylurea entry from long-acting agents to all sulfonylureas. Its recommendation, rated strong: "Avoid sulfonylureas as first- or second-line monotherapy or add-on therapy unless there are substantial barriers to the use of safer and more effective agents. If a sulfonylurea is used, choose short-acting agents (e.g., glipizide) over long-acting agents (e.g., glyburide, glimepiride)."

The panel's reasons were a higher risk of cardiovascular events, death and hypoglycemia than alternative agents, and a higher risk of prolonged hypoglycemia with the long-acting drugs. For an older person still on glyburide, that is a reason to ask at the next review whether glipizide or a different class would suit better, not a reason to stop suddenly.

The cardiovascular warning on the label

Glyburide labels carry a special warning on increased risk of cardiovascular mortality. It comes from the University Group Diabetes Program (UGDP) study of 823 patients in the 1960s, in which people treated for 5 to 8 years with diet plus a fixed dose of tolbutamide (an older sulfonylurea) had a cardiovascular death rate "approximately 2½ times that of patients treated with diet alone." The label says the warning "may also apply to other oral hypoglycemic drugs in this class." This is a class warning based on a different drug, but it remains part of the official label.

Other label warnings

• G6PD deficiency. Sulfonylureas can cause hemolytic anemia in people with G6PD deficiency, and the label says a non-sulfonylurea alternative should be considered. Hemolytic anemia has also been reported after marketing in people without known G6PD deficiency.
• Kidney and liver disease. Both can raise glyburide levels and reduce the liver's ability to make glucose, increasing the risk of serious hypoglycemia.
• Older, frail or malnourished patients. The label calls for conservative starting and maintenance doses.
• Pregnancy and children. The label states that glyburide is not recommended for use in pregnancy or in pediatric patients. It also warns that prolonged severe hypoglycemia (4 to 10 days) has been reported in newborns whose mothers were taking a sulfonylurea at delivery, and that if glyburide is used in pregnancy it should be stopped at least two weeks before the expected delivery date.

Who should not take glyburide

The label lists four contraindications:

• Known hypersensitivity or allergy to glyburide
• Diabetic ketoacidosis, with or without coma (this needs insulin)
• Type 1 diabetes
• Taking bosentan (a pulmonary hypertension drug), because of an increased risk of liver enzyme rises

Drug interactions to know about

Effect	Examples named in the glyburide label
Can increase the blood sugar lowering effect	NSAIDs and other highly protein-bound drugs, salicylates, sulfonamides, chloramphenicol, probenecid, coumarins, MAO inhibitors, beta blockers; ciprofloxacin; oral miconazole (severe hypoglycemia reported)
Can raise blood sugar and weaken control	Thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, isoniazid
Lower glyburide levels	Colesevelam (take glyburide at least 4 hours before it); topiramate
Contraindicated	Bosentan

Beta blockers deserve a special mention: they can both add to the glucose-lowering effect and hide the warning signs of a low, such as a racing heart.

Glyburide in pregnancy and gestational diabetes

Glyburide was once widely used for gestational diabetes. Current US guidance has moved away from it. The American Diabetes Association Standards of Care 2026 state that metformin and glyburide "should not be used as first-line agents for management of diabetes in pregnancy, as both cross the placenta to the fetus," and that insulin is the first-line agent for gestational diabetes in the US. The ADA notes that glyburide concentrations in umbilical cord plasma are about 50 to 70% of the mother's levels, and that data on long-term safety for offspring are "of some concern."

A 2015 BMJ meta-analysis of randomised trials compared glyburide with insulin in gestational diabetes:

Outcome, glyburide vs insulin	Result	95% CI
Birth weight	109 g higher	35.9 to 181 g
Macrosomia (large baby)	Risk ratio 2.62	1.35 to 5.08
Newborn hypoglycemia	Risk ratio 2.04	1.30 to 3.20

The glyburide label adds a practical warning: newborns of mothers taking a sulfonylurea at delivery have had prolonged severe hypoglycemia lasting 4 to 10 days, so if glyburide is used in pregnancy it should be stopped at least two weeks before the expected delivery date. The authors concluded that glibenclamide should not be used for gestational diabetes if insulin or metformin is available. Anyone who is pregnant or planning pregnancy while taking glyburide should talk to their doctor about switching.

What glyburide costs

US pharmacy acquisition prices come from the Medicaid NADAC file. These are what pharmacies pay wholesalers, not the shelf price, which adds dispensing fees and margin and depends on insurance or discount cards. Median generic prices per tablet as of 21 October 2026:

Tablet	NADAC per tablet	Listings that week	30 tablets at NADAC
Glyburide 2.5 mg	$0.06460	10	$1.94
Glyburide 5 mg	$0.06830	12	$2.05
Glyburide micronized 3 mg	$0.12808	2	$3.84
Glyburide micronized 6 mg	$0.23939	1	$7.18
Glipizide 5 mg	$0.03285	20	$0.99
Glipizide 10 mg	$0.04258	19	$1.28
Glimepiride 2 mg	$0.03746	18	$1.12
Glimepiride 4 mg	$0.04643	19	$1.39
Glyburide-metformin 5/500 mg	$0.18992	5	$5.70

The strengths are not dose-equivalent, so the table is for comparing tablet prices, not for choosing a dose. All of these are inexpensive at acquisition cost. Micronized glyburide costs roughly twice as much per tablet as the regular form, and it has very few suppliers. A site quoting a premium price for "Micronase" today is selling something other than the discontinued US brand.

Signs of low blood sugar and what to do

Low blood sugar can cause shakiness, sweating, a fast heartbeat, hunger, confusion, irritability, blurred vision and, if severe, seizures or loss of consciousness. Older people and people on beta blockers may not get the usual warning signs. General advice for anyone on a sulfonylurea:

• Take the tablet with breakfast or the first main meal, as the label directs, and do not skip meals after taking it.
• Keep a fast-acting sugar source with you and know how to use it.
• Check your glucose if you feel unwell, and tell your doctor about any lows.
• Be careful with alcohol, missed meals, severe or prolonged exercise and adding another glucose-lowering drug: the label says hypoglycemia is more likely in each of these situations.
• Get urgent help for confusion, fainting, a seizure or a low that does not respond to sugar. The glyburide label says patients treated for severe hypoglycemia should be monitored for at least 24 to 48 hours, because hypoglycemia may recur after apparent recovery.

Glyburide with metformin

The Glucovance brand of glyburide and metformin is discontinued in the US, but generic glyburide-metformin tablets are still priced in NADAC (5 listings each for 2.5/500 mg and 5/500 mg). Combination tablets mean fewer pills, but they lock the two doses together and cost more per tablet than the two generics bought separately. Metformin carries its own label warnings, including lactic acidosis and kidney limits, covered in our metformin dosage guide and metformin side effects guide.

Questions to ask your doctor

• Is my glyburide the regular or the micronized form, and is my dose right for that form?
• Given my age and kidney function, would glipizide or another class carry less risk of lows?
• How often should I check my glucose, and what level should prompt a call?
• Do any of my other medicines, such as a beta blocker, a sulfonamide antibiotic or a water tablet, change my glyburide dose?
• If I plan a pregnancy, when should I switch to insulin or metformin?

If you are weighing up the newer classes, our Jardiance vs Farxiga and Januvia vs Tradjenta guides compare common options. For a discontinued combination with a similar story, see our Avandaryl guide.

Where SafeRxPills fits

SafeRxPills does not sell Micronase or any US-brand glyburide. We sell Diabetrol (glibenclamide 5 mg with metformin 500 mg, made by Abbott in India), glimepiride as Amaryl 1 mg, Amaryl 2 mg and Glypride 4 mg, and glipizide extended-release as Glynase XL 5 mg and Glynase XL 10 mg (the Indian brand, which is glipizide, not glyburide). These are Indian-market products, not FDA-approved versions, and should be used only on a prescription from a doctor who has reviewed your kidney function and other medicines. For the wider picture, see our type 2 diabetes page and guide to buying Amaryl online.

Sources

1. U.S. Food and Drug Administration. Drugs@FDA entries for NDA 017498 (Micronase), NDA 017532 (DiaBeta), NDA 020051 (Glynase) and NDA 021178 (Glucovance), via openFDA, accessed October 2026.
2. Glyburide tablets USP (non-micronized) 1.25 mg, 2.5 mg and 5 mg, US prescribing information, Teva. Contraindications, Special Warning on Increased Risk of Cardiovascular Mortality, Precautions, Drug Interactions, Dosage and Administration. DailyMed setid a56f100f-0f42-4188-81ab-04644b824040.
3. Glyburide tablets (micronized) 1.5 mg, 3 mg and 6 mg, US prescribing information, Teva. Dosage and Administration. DailyMed setid e84c0dfc-a4e9-4c89-b6ea-45732eb412f5.
4. Glipizide tablets, US prescribing information (Aiping Pharmaceutical, 2026), and GLUCOTROL (glipizide) prescribing information, Pfizer. Dosage and Administration.
5. Glimepiride tablets, US prescribing information (Accord, 2025). Dosage and Administration. DailyMed.
6. Gangji AS, Cukierman T, Gerstein HC, Goldsmith CH, Clase CM. A systematic review and meta-analysis of hypoglycemia and cardiovascular events: a comparison of glyburide with other secretagogues and with insulin. Diabetes Care 2007;30(2):389-94. PMID 17259518.
7. Holstein A, Plaschke A, Egberts EH. Lower incidence of severe hypoglycaemia in patients with type 2 diabetes treated with glimepiride versus glibenclamide. Diabetes Metab Res Rev 2001;17(6):467-73. PMID 11757083.
8. 2023 American Geriatrics Society Beers Criteria Update Expert Panel. American Geriatrics Society 2023 updated AGS Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc 2023;71(7):2052-81. PMID 37139824.
9. American Diabetes Association Professional Practice Committee. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes 2026. Diabetes Care 2026;49(Suppl 1):S321-S338. PMID 41358885.
10. Balsells M, García-Patterson A, Solà I, Roqué M, Gich I, Corcoy R. Glibenclamide, metformin, and insulin for the treatment of gestational diabetes: a systematic review and meta-analysis. BMJ 2015;350:h102. PMID 25609400.
11. Centers for Medicare and Medicaid Services. National Average Drug Acquisition Cost (NADAC), weekly file as of 21 October 2026.

This guide is for information and does not replace advice from a doctor or pharmacist who knows your medical history. Do not stop or change diabetes medicines without medical advice.