Glyburide / metformin

How Medicare covers it

Part D (forms used at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Glyburide-metformin (brand name Glucovance) is used, along with diet and exercise, to improve blood sugar control in adults with type 2 diabetes mellitus.

What it is for, in depth

Glucovance is for adults with type 2 diabetes whose blood sugar needs better control, used as an add-on to diet and exercise — it is not for diabetic ketoacidosis, which the label says should be treated with insulin. It is typically prescribed for someone who needs the combined effect of two different blood-sugar drugs in a single tablet; the label studied it both as first therapy and as second-line therapy. The dose is individualized and raised slowly to find the lowest dose that controls blood sugar, up to a maximum of 20 mg glyburide / 2,000 mg metformin per day, with blood glucose checks during titration and HbA1c about every 3 months. The label's How Supplied section describes a 2.5 mg/500 mg film-coated tablet; the Part D package lists three combination strengths in the formulary file: glyburide 1.25 mg / metformin 250 mg, glyburide 2.5 mg / metformin 500 mg, and glyburide 5 mg / metformin 500 mg tablets.

How it works

This tablet combines two blood-sugar-lowering drugs, glyburide and metformin hydrochloride, in one pill. The label says the two drugs work in complementary (different, matching) ways to improve blood sugar control in type 2 diabetes. The label extract does not spell out each drug's step-by-step mechanism beyond that. The label does note the practical split in side effects: low blood sugar risk is largely due to the glyburide part, and stomach and gut side effects are largely due to the metformin part.

How it is taken

The tablets are taken by mouth with meals. The dose must be set for each person based on how well it works and how well it is tolerated, starting at a low dose and raising it gradually. The maximum recommended daily dose is 20 mg glyburide / 2,000 mg metformin. Blood glucose should be checked during starting and dose changes, and HbA1c should be measured about every 3 months to judge how well treatment is working. The treatment goal is to bring fasting and after-meal blood sugar and HbA1c to normal or as close to normal as possible.

Common side effects

In the label's clinical trials of Glucovance, the most common side effects reported by more than 5% of patients were upper respiratory infection (17.3%), diarrhea (17.0%), headache (8.9%), nausea and vomiting (7.6%), abdominal pain (6.9%), and dizziness (5.5%). Low blood sugar (hypoglycemia) is a key risk, largely from the glyburide part, and stomach and gut effects are largely from the metformin part. Very rarely, a disulfiram-like reaction has been reported in patients treated with glyburide tablets.

Serious warnings

The boxed warning covers lactic acidosis, a rare but serious buildup linked to metformin (see Boxed warning). Glucovance must not be used in people with kidney disease or poor kidney function, in people allergic to metformin or glyburide, or in people with acute or chronic metabolic acidosis, including diabetic ketoacidosis (which should be treated with insulin). It should be temporarily stopped in patients having radiology studies that use injected iodinated contrast dye, because those products may suddenly change kidney function. Switching to Glucovance from taking glyburide (or another sulfonylurea) plus metformin separately can cause blood sugar to go too high or too low, so changes need care and monitoring.

Boxed warning

Boxed warning — lactic acidosis: Lactic acidosis is a rare but serious problem that can happen because metformin builds up during treatment with Glucovance, and when it occurs it is fatal in about 50% of cases. It is marked by high blood lactate levels, lower blood pH, and electrolyte problems. Reported cases have occurred mainly in diabetic patients with serious kidney problems, and the risk rises with worse kidney function and with older age; people with congestive heart failure needing drug treatment, liver disease, conditions causing low oxygen or poor blood flow (such as dehydration, sepsis, shock, or heart attack), and heavy alcohol use are at higher risk. The start is often subtle, with only vague symptoms such as feeling unwell, muscle aches, breathing distress, increasing sleepiness, and vague belly distress, with low body temperature, low blood pressure, and slow heart rhythms that resist treatment as it worsens. Kidney function should be checked regularly, the lowest effective dose used, and treatment should not be started in patients 80 years or older unless kidney testing shows function is not reduced. Glucovance should be withheld with any condition tied to low oxygen, dehydration, or sepsis, stopped before any intravascular radiocontrast study and for surgery, and stopped at once if lactic acidosis is suspected — it is a medical emergency that must be treated in a hospital, and prompt hemodialysis is recommended to correct the acidosis and remove metformin.

Who should be careful

People with kidney disease or reduced kidney function must not take it, and kidney function needs regular monitoring — special care is needed in older patients, and treatment should not start at age 80 or older unless kidney testing shows function is not reduced. People with liver disease should generally avoid it, because a damaged liver may not clear lactate well. People with congestive heart failure, or any condition with low oxygen, dehydration, or sepsis, are at higher risk of lactic acidosis. Patients should be warned against excessive alcohol use. It must be temporarily stopped before radiocontrast studies and surgery.

Major interactions

The label lists drugs that tend to raise blood sugar and may cause loss of blood sugar control: thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blocking drugs, and isoniazid. When such a drug is started, the patient should be watched for loss of control; when it is stopped, the patient should be watched closely for low blood sugar. Alcohol makes metformin's effect on lactate metabolism stronger, raising lactic acidosis risk, so patients should be warned against too much alcohol, whether short-term or long-term. The label also notes metformin is negligibly bound to plasma proteins, so it is less likely than sulfonylureas (which are heavily protein-bound) to interact with highly protein-bound drugs such as salicylates, sulfonamides, chloramphenicol, and probenecid.

Cost and saving notes

Glyburide-metformin is available as a generic combination tablet, so asking for the generic rather than the brand (Glucovance) is usually the lower-cost Part D option — check your plan's drug list to confirm how it is covered. If your plan places it on a higher tier or does not list it, you or your prescriber can ask the plan for a tier exception or a formulary exception. Extra Help, the Part D Low-Income Subsidy, lowers premiums and drug costs for people who qualify based on income and resources. Part D also has an annual out-of-pocket cap: once your covered Part D spending reaches the cap for the year, you pay no more for covered Part D drugs for the rest of that year.

Why it is in its tier

Glyburide / metformin sits on Tier 1 in 54.51% of the plans that list it (598 of 1097 listing plans). Tier 1 is the preferred generic tier — the lowest copays, often $0-$15. The data-visible drivers: It is a generic product, and the CMS dashboard puts its average Part D spending at about $69.12 per beneficiary for 2024 — a relatively low-cost drug, which matches where plans place it. Only 19.96% of Part D plans list it at all, so many readers will find their plan does not list it and covers a similar drug instead. The tier shown is the most common one; individual plans vary.

Sources

• GLUCOVANCE (GLYBURIDE AND METFORMIN HYDROCHLORIDE) TABLET, FILM COATED [PHYSICIANS TOTAL CARE, INC.] — DailyMed
• MedlinePlus — National Library of Medicine
• MedlinePlus — Glyburide and Metformin: MedlinePlus Drug Information

What official patient guides say

In daily life, MedlinePlus says glyburide and metformin tablets are taken one to two times daily with meals, at the same time(s) each day, usually starting at a low dose that the doctor may raise gradually, no more than once every 2 weeks. If you miss a dose, take it as soon as you remember unless it is almost time for the next dose — then skip it and do not take a double dose. Store it at room temperature, tightly closed, away from light, excess heat, and moisture (not in the bathroom), and keep taking it even if you feel well.

Source: MedlinePlus — Glyburide and Metformin: MedlinePlus Drug Information

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

Without insurance, the cash benchmark is $0.1606 per unit (GLYBURIDE-METFORMIN 2.5-500 MG) — about $4.82 for 30 units. NADAC benchmark — the average price pharmacies pay (CMS, as of 2026-11-04). Pharmacy shelf prices vary.

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-08

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 1,097 list Glyburide / metformin — 20.0% of plans. Most of those plans put it on Tier 1: 598 plans, 54.5% of the plans that list it. Other plans place it on Tier 6 (267 plans), Tier 2 (202 plans) or Tier 3 (25 plans). For example: CalOptima Health OneCare Complete (HMO D-SNP) puts it on Tier 1; Univera SeniorChoice Secure (HMO-POS) puts it on Tier 3; Medicare Blue Choice Optimum (HMO-POS) puts it on Tier 3. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan's deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.