Dosing & Uses
Dosage Forms & Strengths
metformin/sitagliptin
tablet
- 500mg/50mg
- 1,000mg/50mg
tablet, extended-release
- 500mg/50mg
- 1,000mg/50mg
- 1,000mg/100mg
Type 2 Diabetes Mellitus
Indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus (T2DM)
Adjust dose gradually considering effectiveness and tolerability
Not currently treated with metformin
- Immediate-release: 50 mg sitagliptin/500 mg metformin PO BID
- Extended-release: 100 mg sitagliptin/1000 mg metformin PO qDay
- Gradually escalate dose to reduce gastrointestinal side effects associated with metformin
- Not to exceed daily dose of 2,000 mg of metformin or 100 mg of sitagliptin
Currently treated with metformin
-
Immediate-release
- Sitagliptin 50 mg PO BID (100 mg/day) and current daily dose of metformin
- For patients taking metformin HCl 850 mg BID, recommended starting dose is 50 mg sitagliptin/1000 mg metformin HCl PO BID
-
Extended-release
- Sitagliptin 100 mg and current daily dose of metformin
- For patients taking metformin HCl immediate-release 850 mg or 1000 mg PO BID, recommended starting dose 100 mg sitagliptin/1000 mg metformin
- Not to exceed daily dose of 2,000 mg of metformin or 100 mg of sitagliptin
Dosage Modifications
Hepatic impairment: Not recommended
Renal impairment
- eGFR 30-45 mL/min/1.73 m2: Not recommended
- eGFR <30 mL/min/1.73 m2: Contraindicated
-
Extended-release only
- If eGFR falls 30-45 mL/min/1.73 m2 during treatment, evaluate risks and benefits of continuing therapy, limit dose of sitagliptin component to 50 mg/day
- If eGFR falls <30 mL/min/1.73 m2 during treatment, discontinue drug
Iodinated contrast imaging procedures
- Discontinue at time of, or before, an iodinated contrast imaging procedure in patients with an eGFR 30-60 mL/min/1.73 m2; in patients with a history of liver disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast
- Reevaluate eGFR 48 hr after imaging procedure; restart if renal function is stable
<18 years: Safety and efficacy not established
Three double-blind, placebo-controlled studies evaluated the efficacy and safety of sitagliptin in patients (n=410) aged 10-17 years with uncontrolled T2DM, with or without insulin therapy; results showed effects of patients treated with sitagliptin were not significantly different from placebo
Type 2 Diabetes Mellitus
Indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus (T2DM)
Initial and maintenance dosing should be conservative due to possibility of decreased renal function
Adjust dose gradually and conservatively considering effectiveness and tolerability
Not currently treated with metformin
- Immediate-release: 50 mg sitagliptin/500 mg metformin PO BID
- Extended-release: 100 mg sitagliptin/1000 mg metformin PO qDay
- Gradually escalate dose to reduce gastrointestinal side effects associated with metformin
- Not to exceed daily dose of 2,000 mg of metformin or 100 mg of sitagliptin
Currently treated with metformin
- Immediate-release
- Sitagliptin 50 mg PO BID (100 mg/day) and current daily dose of metformin
- For patients taking metformin HCl 850 mg BID, recommended starting dose is 50 mg sitagliptin/1000 mg metformin HCl PO BID
- Extended-release
- Sitagliptin 100 mg and current daily dose of metformin
- For patients taking metformin HCl immediate-release 850 mg or 1000 mg PO BID, recommended starting dose 100 mg sitagliptin/1000 mg metformin
- Not to exceed daily dose of 2,000 mg of metformin or 100 mg of sitagliptin
Dosage Modifications
Hepatic impairment: Not recommended
Renal impairment
- eGFR 30-45 mL/min/1.73 m2: Not recommended
- eGFR <30 mL/min/1.73 m2: Contraindicated
- Extended-release only
- If eGFR falls 30-45 mL/min/1.73 m2 during treatment, evaluate risks and benefits of continuing therapy, limit dose of sitagliptin component to 50 mg/day
- If eGFR falls <30 mL/min/1.73 m2 during treatment, discontinue drug
Iodinated contrast imaging procedures
- Discontinue at time of, or before, an iodinated contrast imaging procedure in patients with an eGFR 30-60 mL/min/1.73 m2; in patients with a history of liver disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast
- Reevaluate eGFR 48 hr after imaging procedure; restart if renal function is stable
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Adverse Effects
1-10%
Abdominal pain (2.2%)
Diarrhea (2.4%)
Hypoglycemia (2.1%)
Nausea (1.3%)
Vomiting (1.1%)
Frequency Not Defined
Exfoliative disorder of skin of scalp
Lactic acidosis (rare)
Postmarketing Reports
Hypersensitivity reactions including anaphylaxis, angioedema, rash, urticaria, cutaneous vasculitis, and exfoliative skin conditions including Stevens-Johnson syndrome
Upper respiratory tract infection
Hepatic enzyme elevations
Acute pancreatitis including fatal and nonfatal hemorrhagic and necrotizing pancreatitis
Gastrointestinal: Constipation, vomiting
Neurologic: Headache
Rhabdomyolysis
Worsening renal function, including acute renal failure (sometimes requiring dialysis)
Myalgia, pain in extremity, and back pain
Severe disabling arthralgia
Pruritus
Bullous pemphigoid
Mouth ulceration; stomatitis
Warnings
Black Box Warnings
Lactic acidosis
- Postmarketing cases of metformin-associated lactic acidosis have resulted in death, hypothermia, hypotension, and resistant bradyarrhythmias
- Onset is often subtle, accompanied only by nonspecific symptoms (eg, malaise, myalgias, respiratory distress, somnolence, abdominal pain)
- Characterized by elevated blood lactate levels (>5 mmol/L), anion gap acidosis (without evidence of ketonuria or ketonemia), an increased lactate/pyruvate ratio, and metformin plasma levels generally >5 mcg/mL
- Risk factors include renal impairment, concomitant use of certain drugs (eg, carbonic anhydrase inhibitors such as topiramate), age ≥65 years old, having a radiological study with contrast, surgery and other procedures, hypoxic states (eg, acute congestive heart failure), excessive alcohol intake, and hepatic impairment
- Steps to reduce risk and manage in these high risk groups are provided in the full prescribing information
- If metformin-associated lactic acidosis is suspected, immediately discontinue treatment and institute general supportive measures in a hospital setting; prompt hemodialysis is recommended
Contraindications
Serious hypersensitivity reaction (eg, anaphylaxis, angioedema) to sitagliptin/metformin, sitagliptin, or metformin
Severe renal impairment (eGFR <30 ml/min/1.73 m2)
Acute/chronic metabolic acidosis, including diabetic ketoacidosis
Cautions
Metformin-associated lactic acidosis have been reported; cases primarily occurred in patients with significant renal impairment; assess renal function before initiating, at least annually during treatment, and more frequently in high-risk patients (eg, elderly)
Acute pancreatitis reported, including fatal and nonfatal hemorrhagic or necrotizing pancreatitis; if pancreatitis suspected, discontinue promptly
Heart failure observed with other DPP-4 inhibitors; consider risks and benefits in patients with risk factors for heart failure; monitor for signs and symptoms; if heart failure develops, manage accordingly to standard of care and consider interrupting treatment
Acute renal failure reported, sometimes requiring dialysis; assess renal function before initiation and periodically thereafter
Metformin may lower vitamin B12 levels; monitor hematologic parameters annually and Serious allergic and hypersensitivity reactions (eg, anaphylaxis, angioedema, exfoliative skin conditions including Stevens-Johnson syndrome) reported; promptly stop treatment and assess for other potential causes; appropriately monitor and treat
Severe and disabling arthralgia reported in patients taking DPP-4 inhibitors; consider as a possible cause for severe joint pain and discontinue drug if appropriate
Bullous pemphigoid reported with DPP-4 inhibitor use, which required hospitalization; in reported cases, patients recovered with topical or systemic immunosuppressive treatment and discontinuation of DPP-4 inhibitor; advise to report any developing blisters/erosions; discontinue DPP-4 therapy and consult a dermatologist if bullous pemphigoid suspected
Drug interaction overview
- Sitagliptin is a P-gp and organic anion transporter-3 substrate; weak CYP3A4 and CYP2C8 substrates
-
Insulin or insulin secretagogues
- Increased risk of hypoglycemia when concomitantly used with insulin and/or an insulin secretagogue; consider lowering dose of insulin or insulin secretagogue
-
Carbonic anhydrase inhibitors
- Consider more frequent monitoring
- Coadministration of these drugs may increase the risk for lactic acidosis
-
Drugs that reduce metformin clearance
- Consider benefits and risks of coadministration
- Drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (eg, organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors) could increase systemic exposure to metformin and may increase the risk for lactic acidosis
-
Alcohol
- Warn against alcohol intake during treatment
- Alcohol potentiates the effect of metformin on lactate metabolism
-
Drugs affecting glycemic control
- Closely monitor for loss of blood glucose control
- When such drugs are discontinued, observe closely for hypoglycemia
- Certain drugs (eg, thiazides, corticosteroids) tend to produce hyperglycemia and may lead to loss of glycemic control
Pregnancy & Lactation
Pregnancy
Limited available data in pregnant females are not sufficient to inform a drug-associated risk for major birth defects and miscarriage
Metformin
- Published studies with use during pregnancy have not reported a clear association with drug and major birth defects or miscarriage risks
Pregnancy registry
- Monitors pregnancy outcomes in females exposed to drug during pregnancy
- Encourage patients to report any prenatal exposure to drug by calling 1-800-986-8999
Animal data
- Sitagliptin: No adverse developmental effects were observed when administered to pregnant rats and rabbits during organogenesis at oral doses up to 30x and 20x, respectively, the 100-mg clinical dose, based on AUC
- Metformin: No adverse developmental effects were observed when administered to pregnant Sprague Dawley rats and rabbits during organogenesis at doses up to 2x and 6x, respectively, a 2000-mg clinical dose, based on BSA
Clinical considerations
- Poorly controlled diabetes in pregnancy increases maternal risk for diabetic ketoacidosis, preeclampsia, spontaneous abortions, preterm delivery, still birth, and delivery complications
- Poorly controlled diabetes increases fetal risk for major birth defects, stillbirth, and macrosomia related morbidity
Females and males of reproductive potential
- Discuss potential for unintended pregnancy with premenopausal women as therapy with metformin may result in ovulation in some anovulatory women
Lactation
There is no information regarding presence of drug in human milk, its effects on breastfed infants, or on milk production
Sitagliptin
- Present in rat milk and therefore possibly present in human
Metformin
- Limited published studies report of drug presence in human milk
- No adverse effects reported on breastfed infants exposed to metformin
- No information available on effects of drug on milk production
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Sitagliptin: Dipeptidyl peptidase 4 (DPP-4) inhibitor, thereby increasing and prolonging incretin hormone activity which are inactivated by DPP-4 enzyme. Incretins increase insulin release and synthesis from pancreatic beta cells and reduce glucagon secretion pancreatic alpha cells
Metformin: Biguanide; acts by decreasing endogenous hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization; improves glucose tolerance and lowers both basal and postprandial plasma glucose
Absorption
Sitagliptin
- Mean AUC: 8.52 microM⋅hr (single oral 100-mg dose)
- Peak plasma concentration: 950 nM (single oral 100-mg dose)
- Peak plasma time: 1-4 hr
- Bioavailability: ~87%
Metformin
- Bioavailability: ~50-60%
- Steady-state is reached within 24-48 hr
- Food decreases extent of and slightly delays absorption of metformin (~40% lower mean peak plasma concentration, a 25% lower AUC, and a 35-min delay in peak plasma time following a single 850-mg dose with food, compared to fasting; clinical relevance is unknown
Distribution
Sitagliptin
- Vd= ~198L
- Protein bound: 38%
Metformin
- Vd= ~654L
- Protein bound: >90%
Metabolism
- Sitagliptin: Limited metabolism with CYP3A4 and CYP2C8
- Metformin: No hepatic metabolism
Elimination
Sitagliptin
- Renal clearance: 350 mL/min
- Half-life, terminal: 12.4 hr
- Excretion: Urine (87% [79% unchanged]), feces (13%)
Metformin
- Renal clearance: 350 mL/min
- Half-life: ~6.2 hr (plasma); ~17.6 hr (blood)
- Excretion: Urine (90%, by tubular secretion)
Administration
Oral Administration
Gradually escalate the dose to reduce the gastrointestinal side effects due to metformin
Immediate-release: Administer with meals
Extended-release: Administer with a meal preferably in the evening
Maintain the same total daily dose of sitagliptin and metformin when changing between immediate-release and extended-release, without exceeding the maximum recommended daily dose
Swallow whole tablet; do not split, crush, or chew
Storage
All formulations: Store at 20-25ºC (68-77ºF), excursions permitted to 15-30ºC (59-86ºF)
Images
Patient Handout
Formulary
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