Glimepiride

What it is

Glimepiride is a synthetic sulfonylurea taken as a tablet for type 2 diabetes, first approved in the United States in 1995 and sold as Amaryl and as generics. It is one of the "second-generation" sulfonylureas, the oldest family of oral diabetes drugs still in wide use. It is metabolised by the liver enzyme CYP2C9, which is why inhibitors and inducers of that enzyme change its effect. It is prescription-only and does not occur in food.

What the research says

Glimepiride makes the pancreas release insulin whether or not blood glucose is high, and that single fact explains both its strength and its main danger. It lowers HbA1c about as much as any oral drug - roughly 0.66 to 0.84 percentage points when added to metformin - and in the five-year GRADE trial it held HbA1c under 7.0% better than sitagliptin. It also causes far more low blood sugar than its alternatives: 37.7% of people in the six-year CAROLINA trial had at least one hypoglycaemic adverse event against 10.6% on linagliptin, and severe hypoglycaemia in GRADE was 2.2% against 0.7% on sitagliptin. It has never been shown to prevent heart attacks or strokes; its own label says no drug in this field has conclusive macrovascular evidence, and it still carries a cardiovascular-mortality warning inherited from a 1970s trial of a different sulfonylurea.

Evidence grade: Well established.

How it works

Drug class: Second-generation sulfonylurea (an insulin secretagogue)

Beta cells in the pancreas have a potassium channel that acts as a switch: when it closes, the cell releases insulin. Normally glucose closes it. Glimepiride binds to a receptor on that channel and closes it directly, so insulin comes out whether blood glucose is high or not. That is why glimepiride can drive glucose too low, unlike drugs that only work when glucose is already raised. (Source 1)

What it is used for

• Glimepiride lowers HbA1c as effectively as other oral agents - a network meta-analysis of sulfonylureas added to metformin reports reductions of 0.66 to 0.84 percentage points - and in GRADE it outperformed sitagliptin over five years, though insulin glargine and liraglutide did better still. Evidence: established. (Source 2)
• CAROLINA, the only long active-comparator cardiovascular trial of glimepiride, showed glimepiride and linagliptin produced the same rate of cardiovascular death, heart attack and stroke over a median 6.3 years. There is no placebo-controlled trial showing glimepiride prevents those events, and the label states plainly that no conclusive macrovascular evidence exists for it or any other antidiabetic drug. Evidence: not-supported. (Source 3)
• Sulfonylureas as a class are used first-line in some monogenic diabetes because the genetic defect sits in the very channel they act on. A 42-person phenotyped cohort found a significant HbA1c fall in 51.6% on sulfonylurea monotherapy, sustained over a median 6 years. This is one small uncontrolled cohort of the class, not a trial of glimepiride. Evidence: limited. (Source 4)
• The label states glimepiride should not be used for type 1 diabetes or diabetic ketoacidosis because it would not work - it needs surviving beta cells to act on. No trial evidence to the contrary was found. Evidence: not-supported. (Source 5)

Interactions

• Alcohol (label): Alcohol can push blood sugar either way on glimepiride and the label says the direction is not predictable. Separately, low blood sugar is more likely when alcohol is drunk, which matters most when it replaces food. (Source 6)
• Meals and skipped meals (label): Glimepiride is taken with breakfast or the first main meal of the day, because it releases insulin regardless of what you have eaten. Eating too little, exercising hard, or drinking alcohol all make low blood sugar more likely. (Source 7)
• Nicotinic acid (niacin), thiazide and other diuretics including chlorthalidone, corticosteroids, thyroid hormone (label): These raise blood glucose and so blunt glimepiride's effect; the label groups high-dose nicotinic acid - sold over the counter as a supplement - with diuretics, steroids and thyroid hormone. Adding one may worsen control; stopping one may cause low blood sugar. (Source 6)
• Fluconazole and other CYP2C9 inhibitors (pharmacokinetic study): Fluconazole slows the liver's breakdown of glimepiride, so glimepiride levels rise and blood sugar can fall too far. Rifampin does the reverse and can make control worse. (Source 8)
• Oral miconazole (case reports): Severe low blood sugar has been reported when oral miconazole, an antifungal, was taken with a sulfonylurea. Whether other forms of miconazole do the same is unknown. (Source 9)
• Colesevelam (pharmacokinetic study): Colesevelam binds glimepiride in the gut and cuts how much gets absorbed. Taking glimepiride at least four hours before colesevelam avoids it. (Source 10)
• DPP-4 inhibitors such as sitagliptin (case reports): Combining a sulfonylurea with a DPP-4 inhibitor raises the risk of severe low blood sugar. The sentence quoted here is the opening premise of a 196,138-person cohort study, which then tested whether long-acting sulfonylureas such as glimepiride make the interaction worse than short-acting ones, and found no difference (adjusted hazard ratio 0.87, 95% CI 0.65 to 1.16). Limit: The quoted sentence is this paper's opening statement of an interaction already accepted in the literature, not a finding this study produced. The study's own comparisons - long-acting against short-acting sulfonylureas, and peptidomimetic against non-peptidomimetic DPP-4 inhibitors - both came out null (adjusted hazard ratios 0.87, 95% CI 0.65 to 1.16, and 0.96, 95% CI 0.76 to 1.22). It therefore gives no basis for preferring one drug over another within either class. (Source 11)
• Amiodarone (clinical trial): In a 12,730-person cohort, starting amiodarone while on a sulfonylurea almost doubled the risk of hypoglycaemia needing hospital care compared with starting a different antiarrhythmic. (Source 12)
• Beta-blockers, clonidine, guanethidine and reserpine (label): These can hide the warning signs of low blood sugar - the shakiness and racing heart - so a dangerous fall can go unnoticed until it is severe. (Source 6)

Stopping it

• A 2026 evidence synthesis on de-intensifying diabetes treatment in older adults names insulin and sulfonylureas as the two high-risk classes to pull back, and reports that doing so lowered hypoglycaemia and treatment burden without a clinically important loss of glycaemic control. (Source 13)
• In a pharmacist-led programme, 89 patients aged 80 or over whose HbA1c was 6.5% or lower were identified as candidates for stopping their sulfonylurea; it was stopped in 41% (37 people) and average HbA1c afterwards stayed within guideline goals. This is an uncontrolled service evaluation, not a trial, and there was no comparison group. (Source 14)
• No withdrawal syndrome or rebound effect is described for glimepiride in the sources reached. The label's instructions about stopping concern adverse reactions: stop promptly if a hypersensitivity reaction is suspected. (Source 15)
• The label also warns in the other direction: when a drug that had been raising blood sugar is withdrawn from someone on glimepiride, low blood sugar can follow, so stopping a co-prescribed medicine is itself a hypoglycaemia risk. (Source 6)

What goes wrong

Severe hypoglycaemia was more than three times as common on glimepiride as on sitagliptin in a five-year head-to-head trial. (Source 2)

• Randomized trial, High certainty.
• Size: 5047 participants.
• Who: Adults with type 2 diabetes on metformin.
• How long: Mean 5.0 years.
• Result: Severe hypoglycaemia in 2.2% on glimepiride vs 1.3% glargine, 1.0% liraglutide, 0.7% sitagliptin. Against sitagliptin that is an absolute increase of 1.5 percentage points, about one extra severe episode for every 67 people treated with glimepiride instead over 5 years.
• Funding: independent (NIDDK and others)

Severe hypoglycemia was rare but significantly more frequent with glimepiride (in 2.2% of the participants) than with glargine (1.3%), liraglutide (1.0%), or sitagliptin (0.7%)

In a six-year trial more than a third of people on glimepiride had at least one hypoglycaemic adverse event, nearly four times the rate on linagliptin. (Source 3)

• Randomized trial, High certainty.
• Size: 6033 participants.
• Who: Adults with type 2 diabetes and elevated cardiovascular risk.
• How long: Median 6.3 years.
• Result: At least one hypoglycaemic adverse event in 1132/3010 (37.7%) on glimepiride vs 320/3023 (10.6%) on linagliptin; HR 0.23 (95% CI 0.21 to 0.26) for linagliptin. Absolute increase 27.1 percentage points, about one extra affected person for every 4 treated with glimepiride instead over 6.3 years.
• Funding: industry-funded (linagliptin manufacturer)

At least 1 episode of hypoglycemic adverse events occurred in 320 (10.6%) participants in the linagliptin group and 1132 (37.7%) in the glimepiride group (HR, 0.23 [95% CI, 0.21-0.26])

People carrying reduced-function CYP2C9 variants have a higher risk of sulfonylurea-induced hypoglycaemia. (Source 16)

• Meta-analysis, Low certainty.
• Size: 7 studies (5 cohort, 2 case-control), 2769 patients.
• Who: Adults with type 2 diabetes on a sulfonylurea.
• How long: Varied by study.
• Result: Any variant allele versus wild-type homozygote OR 1.24 (95% CI 1.03 to 1.48); CYP2C92 OR 1.85 (95% CI 1.18 to 2.89); CYP2C93 OR 1.67 (95% CI 0.40 to 6.86), not significant.
• Funding: not stated.

Limit of this finding: The CYP2C9*3 figure in this analysis - an odds ratio of 1.67 - looks like a real effect but is not one: its interval runs from 0.40 to 6.86 and its p-value is 0.48, so the data cannot separate it from no effect at all. Only the overall variant-allele result (1.24, 1.03 to 1.48) and the *2 result (1.85, 1.18 to 2.89) are statistically distinguishable from no effect.

The CYP2C9 variant alleles were associated with an increase in sulfonylurea-induced hypoglycemia compared with wild-type homozygote (OR = 1.24; 95% CI, 1.03-1.48). Compared with CYP2C9 wild-type homozygotes, CYP2C92 allele was associated with increased incidence of hypoglycemia (OR = 1.85; 95% CI, 1.18-2.89), whereas the CYP2C93 allele failed to show the statistical significance (OR = 1.67; 95% CI, 0.40-6.86; P = 0.48).

Starting amiodarone while taking a sulfonylurea roughly doubled the risk of hypoglycaemia severe enough to need hospital care. (Source 12)

• Cohort study, Low certainty.
• Size: 12,730 eligible patients (5325 initiated amiodarone, 7405 a comparator antiarrhythmic)
• Who: Adults with type 2 diabetes on a sulfonylurea starting an oral antiarrhythmic, South Korean national claims data 2011 to 2022.
• How long: 2011 to 2022 follow-up.
• Result: Weighted hazard ratio 1.92 (95% CI 1.12 to 3.30) for severe hypoglycaemia. This is an observational association, not proof of cause, and the paper gives no absolute rates.
• Funding: not stated.

After weighting, amiodarone initiation was associated with a higher risk of severe hypoglycemia compared with initiation of comparator antiarrhythmics (weighted HR 1.92; 95% CI, 1.12-3.30). The increased risk persisted across multiple sensitivity and subgroup analyses.

Sulfonylureas including glimepiride can cause haemolytic anaemia, classically in G6PD deficiency but also reported without it. (Source 17)

• Official position, Certainty not rated.
• Size: Postmarketing reports, denominator unknown.
• Who: People prescribed glimepiride.
• How long: Not stated.
• Result: No rate is given. The label advises considering a non-sulfonylurea alternative in G6PD deficiency.
• Funding: not stated.

Sulfonylureas can cause hemolytic anemia in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency. Because glimepiride is a sulfonylurea, use caution in patients with G6PD deficiency and consider the use of a non-sulfonylurea alternative.

Glimepiride carries a cardiovascular-mortality warning that rests on a 1970s trial of a different sulfonylurea, tolbutamide, not on glimepiride. (Source 18)

• Official position, Very low certainty.
• Size: 823 patients randomised to one of four treatment groups in the University Group Diabetes Program.
• Who: People with non-insulin-dependent diabetes in the UGDP trial.
• How long: 5 to 8 years of treatment.
• Result: The label reports that patients on diet plus fixed-dose tolbutamide 1.5 grams per day had cardiovascular mortality about two and a half times that of patients on diet alone, with no significant increase in total mortality. Tolbutamide was the only sulfonylurea studied; the warning is extended to glimepiride by class analogy, and the label itself notes the interpretation is controversial.
• Funding: not stated.

UGDP reported that patients treated for 5 to 8 years with diet plus a fixed dose of tolbutamide (1.5 grams per day) had a rate of cardiovascular mortality approximately 2 and a half times that of patients treated with diet alone.

The label concedes the cardiovascular-mortality extension to glimepiride is a prudential judgement from chemical similarity, not a finding about glimepiride. (Source 18)

• Official position, Very low certainty.
• Size: Not applicable.
• Who: Regulatory position, label dated 2025-10-17.
• How long: Not applicable.
• Result: No effect size for glimepiride itself.
• Funding: not stated.

Although only one drug in the sulfonylurea class (tolbutamide) was included in this study, it is prudent from a safety standpoint to consider that this warning may also apply to other oral hypoglycemic drugs in this class, in view of their close similarities in mode of action and chemical structure.

In pooled placebo-controlled trials the commonest adverse reactions to glimepiride were hypoglycaemia, dizziness, weakness, headache and nausea. (Source 19)

• Official position, Low certainty.
• Size: Approximately 2,800 patients treated with glimepiride in controlled trials, of whom about 1,700 for at least a year; the adverse-event table pooled 11 placebo-controlled trials with 745 on glimepiride and 294 on placebo.
• Who: Adults with type 2 diabetes in the registration programme.
• How long: 13 weeks to 12 months.
• Result: The label reports events occurring in 5% or more of glimepiride patients and more often than placebo. It warns that trial rates cannot be compared across drugs and may not reflect practice.
• Funding: industry-funded (manufacturer registration trials)

In clinical trials, the most common adverse reactions with glimepiride were hypoglycemia, dizziness, asthenia, headache, and nausea.

The label states severe hypoglycaemia from any sulfonylurea can cause unconsciousness, convulsions, lasting brain injury or death. (Source 7)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: Regulatory position, label dated 2025-10-17.
• How long: Not applicable.
• Result: No rate is given in this passage; the trial rates are 2.2% severe hypoglycaemia over 5 years in GRADE and 37.7% any hypoglycaemic adverse event over 6.3 years in CAROLINA.
• Funding: not stated.

Severe hypoglycemia can lead to unconsciousness or convulsions and may result in temporary or permanent impairment of brain function or death.

What the evidence supports

Sulfonylureas including glimepiride lower HbA1c by about 0.66 to 0.84 percentage points when added to metformin, with little to choose between them on glucose control. (Source 20)

• Meta-analysis, Low certainty.
• Size: 13 trials of sulfonylureas and 14 of non-sulfonylurea oral agents; 16,260 patients.
• Who: Adults with type 2 diabetes inadequately controlled on metformin 1000 mg/day or more.
• How long: 12 to 52 weeks.
• Result: HbA1c reductions of -0.66 to -0.84% (-7 to -9 mmol/mol) across the sulfonylureas, described by the authors as comparable.
• Funding: not stated.

Limit of this finding: Hypoglycaemia was only counted here as a reported adverse event, with the definition varying from study to study, which the authors name as a major limitation. The headline that hypoglycaemia was 'lowest with gliclazide' holds statistically only against glipizide (odds ratio 0.22, credible interval 0.05 to 0.96). The comparisons against glimepiride (0.40, 0.13 to 1.27) and glibenclamide (0.21, 0.03 to 1.48) have intervals that cross 1, so against those two drugs no reliable difference was shown.

Producing comparable reductions in HbA1C of -0.66 to -0.84% (-7 to -9 mmol/mol)

Over five years glimepiride held HbA1c under 7.0% better than sitagliptin but not as well as insulin glargine or liraglutide. (Source 2)

• Randomized trial, High certainty.
• Size: 5047 participants.
• Who: Adults with type 2 diabetes of under 10 years' duration, HbA1c 6.8 to 8.5%, on metformin.
• How long: Mean 5.0 years.
• Result: Rate of reaching confirmed HbA1c of 7.0% or higher per 100 participant-years: glargine 26.5, liraglutide 26.1, glimepiride 30.4, sitagliptin 38.1 (P<0.001 across groups)
• Funding: independent (National Institute of Diabetes and Digestive and Kidney Diseases and others)

the rates with glargine (26.5 per 100 participant-years) and liraglutide (26.1) were similar and lower than those with glimepiride (30.4) and sitagliptin (38.1)

Over a median 6.3 years glimepiride and linagliptin produced the same rate of cardiovascular death, heart attack and stroke. (Source 3)

• Randomized trial, High certainty.
• Size: 6033 of 6042 randomised participants treated and analysed.
• Who: Adults with type 2 diabetes, HbA1c 6.5 to 8.5%, median diabetes duration 6.3 years, elevated cardiovascular risk; 42% with macrovascular disease; mean age 64.0 years, 39.9% women.
• How long: Median 6.3 years.
• Result: Primary outcome 356/3023 (11.8%) on linagliptin vs 362/3010 (12.0%) on glimepiride; HR 0.98 (95.47% CI 0.84 to 1.14), non-inferiority met, superiority not (P=.76). Adjudicated acute pancreatitis 15 (0.5%) vs 16 (0.5%).
• Funding: industry-funded (the trial was a linagliptin cardiovascular safety trial sponsored by its manufacturer)

The primary outcome occurred in 356 of 3023 participants (11.8%) in the linagliptin group and 362 of 3010 (12.0%) in the glimepiride group (HR, 0.98 [95.47% CI, 0.84-1.14]; P < .001 for noninferiority), meeting the noninferiority criterion but not superiority (P = .76).

In a small cohort with HNF4A-related monogenic diabetes, about half responded to sulfonylurea monotherapy and the response lasted years. (Source 4)

• Cohort study, Very low certainty.
• Size: 42 individuals with an HNF4A mutation.
• Who: People phenotyped in detail including oral glucose tolerance testing.
• How long: Median 6 years of follow-up (IQR 3.5 to 11)
• Result: The abstract reports a significant HbA1c reduction (p = 0.045) in '51.6%' of people on sulphonylurea monotherapy, with '48.4%' needing adjunct agents including insulin, and retinopathy in '24.4%', nephropathy 12.9% and coronary heart disease 22.6%. These percentages are reproduced as published but cannot be reconciled with the stated cohort of 42 people, so they are shown here rather than relied on.
• Funding: not stated.

Limit of this finding: The percentages in this abstract cannot be fractions of the 42 people the study phenotyped: 51.6% and 48.4% imply a group of about 31, and 24.4% is not a possible fraction of 42 or of 31 either. They are quoted exactly as published, but they should not be read as 'this many of the 42'. What the paper supports is its direction - about half of this very small group with HNF4A-related monogenic diabetes responded to a sulphonylurea alone and the response lasted years - not the precise figures. This is a single-centre cohort of 42 people with a rare single-gene form of diabetes; none of it carries over to ordinary type 2 diabetes.

Significant HbA1c reduction (p = 0.045) was observed in 51.6% of people with an HNF4A gene mutation on sulphonylurea monotherapy, and glycaemic control persisted after 6 years (IQR: 3.5-11) of follow-up.

What the evidence does not support

Across five years glimepiride did not differ from the three other add-on drugs in microvascular complications, major cardiovascular events or death. (Source 21)

• Randomized trial, Moderate certainty.
• Size: 5047 participants.
• Who: Adults with type 2 diabetes on metformin.
• How long: Mean 5.0 years.
• Result: Overall rates per 100 participant-years: MACE 1.0, heart-failure hospitalisation 0.4, cardiovascular death 0.3, all deaths 0.6, no between-group difference. For 'any cardiovascular disease' glimepiride's hazard ratio against the other three combined was 1.1 (95% CI 0.9 to 1.4), on limits not adjusted for multiple comparisons.
• Funding: independent (NIDDK and others)

Limit of this finding: Each hazard ratio in this passage compares one drug with the other three pooled together, not with any single drug head to head, and the authors say the confidence limits are not adjusted for making several comparisons at once. A figure from this analysis is not a head-to-head result and should not be read as one.

1.1 (95% confidence interval [CI], 0.9 to 1.3) in the glargine group, 1.1 (95% CI, 0.9 to 1.4) in the glimepiride group

The FDA label states no clinical study has established conclusive evidence that glimepiride, or any antidiabetic drug, reduces large-vessel disease. (Source 15)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: Regulatory position held by the FDA, label dated 2025-10-17.
• How long: Not applicable.
• Result: No effect size; this is an explicit statement of absent evidence.
• Funding: not stated.

Macrovascular Outcomes: No clinical studies establishing conclusive evidence of macrovascular risk reduction wit

The label states glimepiride would not work in type 1 diabetes or diabetic ketoacidosis. (Source 5)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: Regulatory position, label dated 2025-10-17.
• How long: Not applicable.
• Result: No effect size; a stated limitation of use.
• Funding: not stated.

Glimepiride tablets should not be used for the treatment of type 1 diabetes mellitus or diabetic ketoacidosis, as it would not be effective in these settings.

Where the evidence is mixed

Among the three commonly used sulfonylureas, glimepiride was associated with the lowest one-year rate of major cardiovascular events but not the lowest hypoglycaemia. (Source 22)

• Cohort study, Low certainty.
• Size: Weighted cohort of 314,699 patients.
• Who: Adults 21 and over with type 2 diabetes and moderate cardiovascular risk starting glimepiride, glipizide or glyburide, US claims and Medicare data 2014 to 2021.
• How long: One year, with follow-up through 2022.
• Result: One-year MACE 2.5% glimepiride, 2.7% glipizide, 2.8% glyburide; versus glimepiride, glyburide HR 1.10 (95% CI 1.05 to 1.16) and glipizide HR 1.05 (1.03 to 1.07). One-year severe hypoglycaemia 0.3%, 0.3% and 0.4%; glipizide had a lower risk than glimepiride, HR 0.82 (0.77 to 0.87). Target trial emulation of observational data, so associations, not proof of cause.
• Funding: not stated.

At 1 year, severe hypoglycemia was experienced by 0.3%, 0.3% and 0.4% of patients starting glimepiride, glipizide and glyburide, respectively. Glyburide was associated with a greater risk of severe hypoglycemia compared with glipizide (HR 1.43, 95% CI 1.23 to 1.65), while glipizide was associated with a lower risk compared with glimepiride (HR 0.82, 95% CI 0.77 to 0.87).

Where the research disagrees

Whether glimepiride causes more low blood sugar than other second-generation sulfonylureas

• Network meta-analysis of randomised trials, British Journal of Clinical Pharmacology, 2016, network meta-analysis of 27 randomised trials, 16,260 patients; the glimepiride comparison was not statistically significant and definitions of hypoglycaemia varied: the risk of hypoglycaemia was lowest with gliclazide compared to glipizide (OR 0.22, CrI: 0.05 to 0.96), glimepiride (OR 0.40, CrI: 0.13 to 1.27), and glibenclamide (OR 0.21, CrI: 0.03 to 1.48) (Source 20)
• Target trial emulation of US claims and Medicare data, BMJ Open Diabetes Research and Care, 2026, observational target trial emulation, 314,699 weighted patients, one-year outcomes: Glyburide was associated with a greater risk of severe hypoglycemia compared with glipizide (HR 1.43, 95% CI 1.23 to 1.65), while glipizide was associated with a lower risk compared with glimepiride (HR 0.82, 95% CI 0.77 to 0.87) (Source 22)

Whether sulfonylureas carry a cardiovascular hazard

• FDA label for glimepiride, dated 2025-10-17, carrying the University Group Diabetes Program warning, regulatory position extrapolated from one 1970s randomised trial of tolbutamide in 823 patients: The administration of oral hypoglycemic drugs has been reported to be associated with increased cardiovascular mortality as compared to treatment with diet alone or diet plus insulin. (Source 18)
• CAROLINA investigators, JAMA, 2019, randomised, double-blind, active-controlled trial, 6033 participants, median 6.3 years: The primary outcome occurred in 356 of 3023 participants (11.8%) in the linagliptin group and 362 of 3010 (12.0%) in the glimepiride group (HR, 0.98 [95.47% CI, 0.84-1.14] (Source 3)

How much

• Reference intake: There is no reference intake for a prescription medicine; the dose is set by the prescriber. As a position, the FDA label in force on 2025-10-17 gives a starting dose of 1 mg or 2 mg once daily with breakfast or the first main meal, 1 mg for people at higher risk of hypoglycaemia, raised in 1 mg or 2 mg steps no more often than every 1 to 2 weeks. (Source 10)
• Upper limit: As a position, the label's maximum is 8 mg once daily (label dated 2025-10-17). No independent upper limit is set by any scientific body. (Source 10)
• Studied: CAROLINA randomised 3010 people to glimepiride 1 to 4 mg once daily against 3023 on linagliptin 5 mg once daily, on top of usual care, for a median 6.3 years. (Source 23)
• Studied: GRADE randomised 5047 people on metformin to add glimepiride, sitagliptin, liraglutide or insulin glargine for a mean of 5.0 years. (Source 24)
• Studied: The label's pooled adverse-event table covers glimepiride doses ranging from 1 to 16 mg daily across eleven placebo-controlled trials of 13 weeks to 12 months. (Source 19)
• Studied: The sulfonylurea network meta-analysis pooled 13 trials of sulfonylureas added to metformin at 1000 mg/day or more, lasting 12 to 52 weeks. (Source 20)

A common belief, and what the research shows

The belief: Glimepiride is an old drug that damages the heart, so it should never be used.

What the research shows: The cardiovascular warning on the label is real but second-hand. It comes from a 1970s trial of tolbutamide, a different sulfonylurea, and the label itself says so: "Although only one drug in the sulfonylurea class (tolbutamide) was included in this study, it is prudent from a safety standpoint to consider that this warning may also apply to other oral hypoglycemic drugs in this class, in view of their close similarities in mode of action and chemical structure." When glimepiride was finally tested head-to-head for 6.3 years in CAROLINA, cardiovascular death, heart attack and stroke occurred in 12.0% on glimepiride and 11.8% on linagliptin. The real, well-measured problem with glimepiride is hypoglycaemia, not the heart.

Questions and answers

What is it?

Glimepiride is a prescription tablet for type 2 diabetes, first approved in the United States in 1995 and sold as Amaryl and as generics. It is a sulfonylurea - the oldest family of oral diabetes drugs still widely used. It is not a nutrient and is not found in any food. (Source 25)

What does it do in the body?

It makes the pancreas release insulin. Beta cells have a potassium channel that triggers insulin release when it closes; glimepiride binds a receptor on that channel and closes it directly. Because it does not wait for blood glucose to be high, it can push glucose below normal - which is the source of its main risk. (Source 1)

Is it good or bad for you?

It is genuinely effective at lowering blood sugar and genuinely more dangerous than its alternatives for one specific harm. In GRADE it beat sitagliptin at holding HbA1c under 7.0% over five years. In the same trial severe hypoglycaemia hit 2.2% on glimepiride against 0.7% on sitagliptin, and in CAROLINA 37.7% had at least one hypoglycaemic event against 10.6% on linagliptin. It has never been shown to prevent heart attacks or strokes. (Source 3)

How do you get more of it?

You cannot get more outside a prescription; it is in no food or supplement. The dose is a prescriber's decision. As a position, the label in force on 2025-10-17 starts at 1 mg or 2 mg once daily with breakfast or the first main meal, rises in 1 mg or 2 mg steps no more often than every one to two weeks, and stops at 8 mg once daily. People at higher risk of low blood sugar start at 1 mg. (Source 10)

If it is harmful, what reduces it?

The literature on reducing or stopping it is the deprescribing literature, and it is reassuring: de-intensifying sulfonylureas in older adults lowered hypoglycaemia and treatment burden without a clinically important loss of glucose control, and in one pharmacist-led programme among people aged 80 and over, stopping it in 41% left average HbA1c still within guideline goals. Several co-prescribed drugs also blunt its effect - diuretics such as chlorthalidone, steroids, thyroid hormone, high-dose nicotinic acid - which is a reason control can drift, not a way to use them. (Source 13)

Why might someone be low in it or missing it?

Nobody is naturally low in glimepiride; the question maps onto being on a smaller dose or none. The label starts people at 1 mg rather than 2 mg when they are older or have reduced kidney function, both of which raise hypoglycaemia risk, and it says debilitated or malnourished people and those with adrenal, pituitary or liver problems are particularly susceptible. People with type 1 diabetes are not given it at all because it would not work. (Source 7)

Which whole foods contain it or feed it?

No food contains glimepiride. Food matters for a different reason: the tablet is taken with breakfast or the first main meal, because it releases insulin whether or not you have eaten. Skipping or shrinking that meal, hard exercise, or alcohol all make low blood sugar more likely. One over-the-counter supplement, high-dose nicotinic acid (niacin), is listed on the label among the things that raise blood sugar and so work against it. (Source 10)

What happens if you do not have it?

Without glimepiride, or something in its place, blood sugar sits higher: sulfonylureas added to metformin lower HbA1c by about 0.66 to 0.84 percentage points. What does not change is cardiovascular risk - over a median 6.3 years in CAROLINA, 12.0% on glimepiride and 11.8% on linagliptin had a cardiovascular death, heart attack or stroke, and across five years in GRADE none of the four drugs differed on major cardiovascular events or death. (Source 21)

How can you test for it?

There is no routine blood test for glimepiride itself. HbA1c is the measure of whether it is working - in GRADE it was checked quarterly and a result had to be confirmed before it counted. Blood glucose is what matters day to day, and in the registration trials a reported hypoglycaemic episode often had a glucose measurement attached rather than being symptom-only. Genotyping for CYP2C9 has been proposed to predict who is most prone to hypoglycaemia, on the strength of a meta-analysis of seven studies in 2769 patients, but that is a research proposal rather than standard care. (Source 26)

References

1. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - full prescribing information. 2025. Read the source
2. The New England journal of medicine. Glycemia Reduction in Type 2 Diabetes - Glycemic Outcomes.. 2022. PMID 36129996, DOI 10.1056/nejmoa2200433. Read the source
3. JAMA. Effect of Linagliptin vs Glimepiride on Major Adverse Cardiovascular Outcomes in Patients With Type 2 Diabetes: The CAROLINA Randomized Clinical Trial.. 2019. PMID 31536101, DOI 10.1001/jama.2019.13772. Read the source
4. Diabetic medicine : a journal of the British Diabetic Association. Sulphonylurea efficacy and end-organ outcomes in the management of HNF4A-MODY.. 2025. PMID 40954556, DOI 10.1111/dme.70139. Read the source
5. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - Full Prescribing Information, section 1 INDICATIONS AND USAGE. 2025. Read the source
6. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - full prescribing information. 2025. Read the source
7. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - full prescribing information. 2025. Read the source
8. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - full prescribing information. 2025. Read the source
9. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - Highlights of Prescribing Information, DRUG INTERACTIONS. 2025. Read the source
10. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - full prescribing information. 2025. Read the source
11. Clinical pharmacology and therapeutics. Pharmacologic Heterogeneity and Risk of Severe Hypoglycemia with Concomitant Use of Sulfonylureas and DPP-4 Inhibitors: Population-Based Cohort Study. [abstract: background, aim and methods]. 2023. PMID 37326010, DOI 10.1002/cpt.2975. Read the source
12. Diabetes, obesity & metabolism. Risk of Severe Hypoglycemia Associated With Concomitant Use of Sulfonylureas and Amiodarone.. 2026. PMID 42517252, DOI 10.1111/dom.71082. Read the source
13. Clinical interventions in aging. Frailty-Informed Deprescribing of Glucose-Lowering Therapy in Older Adults with Type 2 Diabetes: A Pragmatic Clinical Framework. [a targeted evidence synthesis with an author-constructed decision framework, not a systematic review or meta-analysis; structured-abstract section 'Results']. 2026. PMID 42436877, DOI 10.2147/cia.s622440. Read the source
14. Journal of the American Pharmacists Association : JAPhA. Pharmacist-led sulfonylurea deprescribing in older adults. [structured-abstract section 'Results']. 2025. PMID 40118449, DOI 10.1016/j.japh.2025.102387. Read the source
15. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - Highlights of Prescribing Information, WARNINGS AND PRECAUTIONS. 2025. Read the source
16. Clinical therapeutics. Association Between the CYP2C9 Genotype and Hypoglycemia Among Patients With Type 2 Diabetes Receiving Sulfonylurea Treatment: A Meta-analysis.. 2021. PMID 33840516, DOI 10.1016/j.clinthera.2021.03.008. Read the source
17. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - full prescribing information. 2025. Read the source
18. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - Full Prescribing Information, section 5.4 Increased Risk of Cardiovascular Mortality with Sulfonylureas. 2025. Read the source
19. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - full prescribing information. 2025. Read the source
20. British journal of clinical pharmacology. Hypoglycaemia when adding sulphonylurea to metformin: a systematic review and network meta-analysis.. 2016. PMID 27426428, DOI 10.1111/bcp.13059. Read the source
21. The New England journal of medicine. Glycemia Reduction in Type 2 Diabetes - Microvascular and Cardiovascular Outcomes.. 2022. PMID 36129997, DOI 10.1056/nejmoa2200436. Read the source
22. BMJ open diabetes research & care. Comparative safety of sulfonylurea therapies on cardiovascular and severe hypoglycemia outcomes among adults with type 2 diabetes and moderate cardiovascular risk: a target trial emulation.. 2026. PMID 41760122, DOI 10.1136/bmjdrc-2025-005646. Read the source
23. JAMA. Effect of Linagliptin vs Glimepiride on Major Adverse Cardiovascular Outcomes in Patients With Type 2 Diabetes: The CAROLINA Randomized Clinical Trial. [structured-abstract section 'Interventions']. 2019. PMID 31536101, DOI 10.1001/jama.2019.13772. Read the source
24. The New England journal of medicine. Glycemia Reduction in Type 2 Diabetes - Glycemic Outcomes.. 2022. PMID 36129996, DOI 10.1056/nejmoa2200433. Read the source
25. DailyMed / Accord Healthcare Inc (FDA label). GLIMEPIRIDE tablets, for oral use - Highlights of Prescribing Information, INDICATIONS AND USAGE. 2025. Read the source
26. Clinical therapeutics. Association Between the CYP2C9 Genotype and Hypoglycemia Among Patients With Type 2 Diabetes Receiving Sulfonylurea Treatment: A Meta-analysis.. 2021. PMID 33840516, DOI 10.1016/j.clinthera.2021.03.008. Read the source