Sitagliptin SUN: Uses, Dosage & Side Effects
A DPP-4 inhibitor (dipeptidyl peptidase-4 inhibitor) used to lower blood sugar levels in adults with type 2 diabetes mellitus, alone or in combination with other antidiabetic medicines
Sitagliptin SUN is a prescription medicine containing sitagliptin, a DPP-4 inhibitor used to control blood sugar levels in adults with type 2 diabetes. It works by increasing the body's own insulin production after meals and reducing excessive sugar production. Available in 25 mg, 50 mg, and 100 mg film-coated tablets, it can be taken once daily with or without food, either alone or alongside other diabetes treatments such as metformin, sulfonylureas, or insulin.
Quick Facts
Key Takeaways
- Sitagliptin SUN is a DPP-4 inhibitor that helps control blood sugar in type 2 diabetes by boosting your body's natural insulin response after meals.
- The standard dose is 100 mg once daily, but lower doses (25 mg or 50 mg) are available for patients with kidney impairment.
- It can be used alone or combined with metformin, sulfonylureas, pioglitazone, or insulin for better glucose control.
- Unlike sulfonylureas and insulin, sitagliptin alone has a low risk of causing hypoglycemia (low blood sugar).
- Report severe abdominal pain immediately to your doctor, as rare cases of pancreatitis have been associated with DPP-4 inhibitors.
What Is Sitagliptin SUN and What Is It Used For?
Sitagliptin SUN contains the active substance sitagliptin, which belongs to a class of medicines known as DPP-4 inhibitors (dipeptidyl peptidase-4 inhibitors). These medicines work by targeting the incretin system, a natural hormonal pathway that plays a key role in regulating blood sugar after eating. When you consume a meal, your gut releases incretin hormones—primarily glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)—that signal the pancreas to produce insulin. The enzyme DPP-4 normally breaks down these incretins within minutes. Sitagliptin inhibits this enzyme, allowing incretin hormones to remain active for longer and thereby enhancing insulin secretion in a glucose-dependent manner.
This glucose-dependent mechanism is particularly important because it means that sitagliptin primarily stimulates insulin release when blood sugar is elevated, such as after a meal. When blood sugar levels are normal or low, the incretin effect is reduced, which gives sitagliptin a lower intrinsic risk of causing hypoglycemia compared to older diabetes medications such as sulfonylureas. In addition to boosting insulin, sitagliptin also reduces glucagon secretion—a hormone that signals the liver to release stored glucose—which further helps to control post-meal blood sugar spikes.
Your doctor may prescribe Sitagliptin SUN to help lower blood sugar that is too high due to type 2 diabetes. This medicine can be used in several ways: as monotherapy when diet and exercise alone are insufficient and metformin is not appropriate; in dual therapy alongside metformin, a sulfonylurea, pioglitazone (a thiazolidinedione), or insulin; or in triple therapy combining sitagliptin with metformin and a sulfonylurea, metformin and pioglitazone, or metformin and insulin. In all cases, it should be used alongside an appropriate diet and exercise programme recommended by your healthcare provider.
Understanding Type 2 Diabetes
Type 2 diabetes mellitus is a chronic metabolic condition characterised by insulin resistance and progressive beta-cell dysfunction. In this condition, the body either does not produce enough insulin or the cells become resistant to the effects of insulin, leading to elevated blood glucose levels. Over time, persistently high blood sugar can damage blood vessels and nerves, potentially leading to serious complications including cardiovascular disease, chronic kidney disease, retinopathy (vision loss), peripheral neuropathy, and impaired wound healing that may necessitate amputation.
According to the International Diabetes Federation (IDF), approximately 537 million adults worldwide were living with diabetes in 2021, with type 2 diabetes accounting for around 90% of all cases. The condition is closely linked to modifiable risk factors including obesity, physical inactivity, and unhealthy dietary patterns, as well as non-modifiable factors such as genetic predisposition, ethnicity, and age. Effective management of type 2 diabetes typically involves a combination of lifestyle modifications (diet, exercise, weight management) and pharmacological therapy to achieve and maintain glycaemic targets, which are generally set at an HbA1c level below 7% (53 mmol/mol) for most adults, as recommended by both the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD).
How DPP-4 Inhibitors Fit Into Diabetes Treatment
DPP-4 inhibitors, sometimes called gliptins, occupy an important position in the treatment algorithm for type 2 diabetes. According to the 2022 ADA/EASD consensus report on the management of hyperglycaemia, DPP-4 inhibitors are considered a reasonable second-line option after metformin, particularly for patients who need additional glucose lowering but for whom weight neutrality and a low risk of hypoglycemia are priorities. They are generally well tolerated, weight-neutral, and have a convenient once-daily oral dosing schedule.
While newer drug classes such as SGLT2 inhibitors and GLP-1 receptor agonists have gained prominence due to demonstrated cardiovascular and renal benefits, DPP-4 inhibitors remain widely used globally. They are particularly useful for patients who cannot tolerate or have contraindications to other medication classes, and in healthcare settings where cost or access to injectable therapies may be a concern. Sitagliptin was the first DPP-4 inhibitor to receive regulatory approval, initially authorised by the U.S. FDA in 2006 and subsequently approved in the European Union and many other countries worldwide.
What Should You Know Before Taking Sitagliptin SUN?
Contraindications
You must not use Sitagliptin SUN if you are allergic (hypersensitive) to sitagliptin or any of the other ingredients contained in the tablet formulation. Serious allergic reactions, including anaphylaxis, angioedema, and exfoliative skin conditions such as Stevens-Johnson syndrome, have been reported in post-marketing experience with sitagliptin. If you have previously experienced any allergic reaction to a DPP-4 inhibitor, you should inform your healthcare provider before starting treatment.
Sitagliptin SUN is specifically indicated for type 2 diabetes and should not be used in patients with type 1 diabetes, as it will not be effective in this condition. It is also not appropriate for the treatment of diabetic ketoacidosis (DKA), a serious complication of diabetes characterised by high blood sugar, rapid weight loss, nausea, or vomiting, and elevated ketone levels in the blood and urine.
Warnings and Precautions
Cases of acute pancreatitis, including fatal and non-fatal haemorrhagic or necrotising pancreatitis, have been reported in patients taking sitagliptin. If you experience severe, persistent abdominal pain that may radiate to the back, with or without nausea and vomiting, stop taking Sitagliptin SUN immediately and contact your doctor. If pancreatitis is confirmed, treatment should not be restarted.
Before starting and during treatment with Sitagliptin SUN, inform your doctor if you have or have had any of the following conditions:
- Pancreatic disease: A history of pancreatitis increases the risk of recurrence. Your doctor will carefully evaluate whether sitagliptin is appropriate for you.
- Gallstones, alcohol dependence, or very high triglyceride levels: These conditions can increase the risk of developing pancreatitis while taking DPP-4 inhibitors.
- Kidney problems: If you have moderate to severe kidney impairment, your doctor will prescribe a lower dose of sitagliptin. Kidney function should be assessed before starting treatment and periodically thereafter.
- Bullous pemfigoid: Cases of this blistering skin condition have been reported with DPP-4 inhibitors. If you develop blisters on the skin, contact your doctor, who may advise you to stop taking Sitagliptin SUN.
Sitagliptin alone does not typically cause low blood sugar (hypoglycemia) because its mechanism of action is glucose-dependent. However, when used in combination with a sulfonylurea (such as glimepiride or gliclazide) or with insulin, the risk of hypoglycemia increases. Your doctor may reduce the dose of your sulfonylurea or insulin when adding sitagliptin to your treatment regimen. Learn to recognise the signs of low blood sugar: sweating, shakiness, fast heartbeat, hunger, dizziness, and confusion.
Children and Adolescents
Sitagliptin SUN is not recommended for use in children and adolescents under 18 years of age. Clinical studies in paediatric patients aged 10 to 17 years with type 2 diabetes did not demonstrate sufficient efficacy to support its use in this population. No data are available for children under 10 years, and safety and efficacy have not been established in this age group.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to have a baby, you should consult your doctor before taking Sitagliptin SUN. This medicine should not be used during pregnancy due to insufficient human data regarding its safety. Animal studies have not indicated direct harmful effects on fertility or embryonic development, but as a precautionary measure, sitagliptin should be avoided in pregnancy.
It is not known whether sitagliptin passes into human breast milk. Studies in rats have shown that sitagliptin is secreted in breast milk. As a precautionary measure, you should not use Sitagliptin SUN if you are breastfeeding or planning to breastfeed. Your doctor will help you decide on a suitable alternative diabetes treatment during this period.
Driving and Operating Machinery
Sitagliptin SUN has no or negligible direct effect on the ability to drive and use machines. However, dizziness and drowsiness have been reported by some patients, which could affect your ability to drive or operate machinery safely. When used in combination with sulfonylureas or insulin, low blood sugar (hypoglycemia) may also impair your reaction time. Take care when driving or using machines, particularly when starting the medication or adjusting the dose.
Important Information About Ingredients
Sitagliptin SUN film-coated tablets contain less than 1 mmol (23 mg) sodium per tablet, meaning they are essentially sodium-free. The tablets also contain hydrogenated castor oil, which may cause stomach upset and diarrhoea in some patients.
How Does Sitagliptin SUN Interact with Other Drugs?
One of the advantages of sitagliptin compared to some other diabetes medications is its relatively low potential for drug-drug interactions. Sitagliptin is not a significant inhibitor or inducer of the cytochrome P450 enzyme system, which is the primary metabolic pathway for many commonly prescribed drugs. Nevertheless, some interactions do exist and should be taken into consideration:
Clinically Relevant Interactions
| Interacting Drug | Effect | Clinical Action |
|---|---|---|
| Digoxin | Sitagliptin may slightly increase plasma digoxin levels | Appropriate monitoring of digoxin levels is recommended when co-administered |
| Sulfonylureas (e.g. glimepiride, gliclazide, glipizide) | Increased risk of hypoglycemia due to additive glucose-lowering effects | A lower dose of sulfonylurea may be required to reduce the risk of low blood sugar |
| Insulin | Increased risk of hypoglycemia when used in combination | A lower dose of insulin may be needed; monitor blood sugar more frequently |
| Metformin | No clinically meaningful pharmacokinetic interaction | No dose adjustment required; combination is widely used and well studied |
| Cyclosporin | Cyclosporin (a potent P-glycoprotein inhibitor) may increase sitagliptin exposure | The clinical significance is not expected to be major; no dose adjustment is recommended |
Low Interaction Potential
Clinical studies have evaluated the pharmacokinetic interaction of sitagliptin with a number of commonly prescribed medicines, including metformin, rosiglitazone, glyburide, simvastatin, warfarin, and oral contraceptives (norethindrone and ethinyl estradiol). In these studies, sitagliptin did not meaningfully alter the pharmacokinetics of these drugs, and co-administration did not meaningfully alter the pharmacokinetics of sitagliptin. Based on this evidence, sitagliptin is considered unlikely to cause clinically relevant interactions with substrates of CYP3A4, CYP2C8, CYP2C9, or P-glycoprotein.
Always inform your doctor or pharmacist about all medicines you are currently taking, have recently taken, or might take, including herbal supplements and over-the-counter products. This ensures that your healthcare team can monitor for any potential interactions and make appropriate dose adjustments where needed.
What Is the Correct Dosage of Sitagliptin SUN?
Always take Sitagliptin SUN exactly as your doctor has told you. Check with your doctor or pharmacist if you are unsure about your prescribed dosage. Your doctor will determine the appropriate dose based on your individual clinical situation, including your kidney function and any other diabetes medicines you are taking.
Adults
Standard Dosage
The recommended dose is one 100 mg tablet once daily, taken by mouth. You may take sitagliptin with or without food, at any time of day that is convenient for you. However, taking it at approximately the same time each day can help establish a consistent routine and improve adherence.
| Kidney Function (eGFR) | Recommended Dose | Notes |
|---|---|---|
| Normal or mild impairment (eGFR ≥ 45 mL/min) | 100 mg once daily | No dose adjustment required |
| Moderate impairment (eGFR 30–44 mL/min) | 50 mg once daily | Dose reduction necessary due to reduced renal clearance |
| Severe impairment or end-stage renal disease (eGFR < 30 mL/min), including dialysis | 25 mg once daily | Can be taken without regard to the timing of dialysis |
Your doctor will assess your kidney function before prescribing Sitagliptin SUN and may periodically re-evaluate it during treatment to ensure the dose remains appropriate. Sitagliptin is primarily excreted by the kidneys, so dose adjustments are essential for patients with reduced renal function to prevent excessive drug accumulation.
Children
Paediatric Use
Sitagliptin SUN is not recommended for children and adolescents under 18 years of age. Clinical trials in children aged 10 to 17 years with type 2 diabetes did not show adequate efficacy. No data are available for children under 10 years of age.
Elderly
Use in Older Adults
No dose adjustment is needed based solely on age. However, since renal function tends to decline with age, elderly patients should have their kidney function monitored, and the dose should be adjusted accordingly using the guidelines above. Clinical studies have included patients aged 65 years and older, and the safety and efficacy profile was comparable to that observed in younger adults.
Missed Dose
If you forget to take a dose, take it as soon as you remember. If you do not remember until it is time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose on the same day to make up for a forgotten dose. If you frequently forget to take your medicine, speak with your doctor or pharmacist about strategies to help you remember.
Overdose
If you have taken more than the prescribed dose of Sitagliptin SUN, contact your doctor or nearest emergency department immediately. In clinical trials, single doses of up to 800 mg were generally well tolerated, but any overdose should be treated as a medical concern. Supportive care and monitoring are recommended, and sitagliptin is modestly dialysable (approximately 13.5% removed during a 3–4 hour haemodialysis session).
Stopping Treatment
Do not stop taking Sitagliptin SUN without talking to your doctor first, even if you feel well. This medicine helps control your blood sugar levels on an ongoing basis, and stopping it may cause your blood sugar to rise to harmful levels. Continuation of treatment should be decided jointly by you and your healthcare provider based on your overall diabetes management plan.
What Are the Side Effects of Sitagliptin SUN?
Like all medicines, Sitagliptin SUN can cause side effects, although not everyone will experience them. The frequency and nature of side effects can vary depending on whether sitagliptin is used alone or in combination with other diabetes medicines. The information below summarises the known side effects based on clinical trials and post-marketing surveillance data.
- Severe and persistent pain in the abdomen (stomach area) that may radiate to the back, with or without nausea and vomiting — signs of pancreatitis
- A serious allergic reaction: rash, hives, blisters or peeling skin, swelling of the face, lips, tongue, or throat causing difficulty breathing or swallowing
Side Effect Frequency Overview
Very Common
May affect more than 1 in 10 people
- Low blood sugar (hypoglycemia) — when used with a sulfonylurea and metformin
Common
May affect up to 1 in 10 people
- Low blood sugar (hypoglycemia) — when used alone or with metformin
- Headache
- Upper respiratory tract infection
- Stuffy or runny nose and sore throat (nasopharyngitis)
- Osteoarthritis (joint disease)
- Pain in arms or legs
- Nausea
- Flatulence (gas)
- Vomiting
- Constipation
- Swollen hands or legs (peripheral oedema) — when used with pioglitazone
- Influenza-like symptoms — when used with insulin
Uncommon
May affect up to 1 in 100 people
- Dizziness
- Constipation
- Itching (pruritus)
- Dry mouth
- Drowsiness (somnolence)
- Stomach pain
- Diarrhoea
Rare
May affect up to 1 in 1,000 people
- Decreased platelet count (thrombocytopenia)
Not Known
Frequency cannot be estimated from available data
- Kidney problems (sometimes requiring dialysis)
- Vomiting
- Joint pain (arthralgia)
- Muscle pain (myalgia)
- Back pain
- Interstitial lung disease
- Bullous pemfigoid (a type of skin blistering)
- Severe allergic reactions (anaphylaxis, angioedema)
Side Effects in Combination Therapy
The side effect profile of sitagliptin can vary depending on the combination therapy used. When added to metformin, the most commonly reported additional effects are nausea, flatulence, and gastrointestinal discomfort, which are largely attributable to metformin rather than sitagliptin itself. When combined with pioglitazone, peripheral oedema (swelling of hands and feet) is more commonly observed. When used with insulin, influenza-like symptoms and dry mouth have been reported.
It is worth noting that in large cardiovascular outcome trials, particularly the TECOS trial (Trial Evaluating Cardiovascular Outcomes with Sitagliptin), sitagliptin demonstrated cardiovascular safety with no increased risk of major adverse cardiovascular events, heart failure hospitalisation, or pancreatitis compared to placebo, when added to standard diabetes care.
If you experience any side effects, talk to your doctor, pharmacist, or nurse. This includes any possible side effects not listed above. You can also report side effects directly to your national pharmacovigilance authority. By reporting side effects, you help provide more information on the safety of this medicine.
How Should You Store Sitagliptin SUN?
Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date stated on the blister and carton after "EXP". The expiry date refers to the last day of that month.
There are no special storage conditions for Sitagliptin SUN film-coated tablets. They should be stored at room temperature, protected from excessive heat and moisture. Keep the tablets in the original packaging (blister or bottle) until you are ready to take them, as this protects them from environmental degradation.
Do not dispose of medicines in wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures help protect the environment and prevent accidental exposure to unused medications.
What Does Sitagliptin SUN Contain?
Active Ingredient
Each tablet contains sitagliptin fumarate equivalent to the stated amount of sitagliptin:
- Sitagliptin SUN 25 mg: sitagliptin fumarate equivalent to 25 mg sitagliptin
- Sitagliptin SUN 50 mg: sitagliptin fumarate equivalent to 50 mg sitagliptin
- Sitagliptin SUN 100 mg: sitagliptin fumarate equivalent to 100 mg sitagliptin
Inactive Ingredients
Tablet core: calcium hydrogen phosphate (E341), crospovidone type A (E1202), hydrogenated castor oil, glycerol dibehenate, magnesium stearate (E470b).
Film coating: hypromellose 2910/5 (E464), titanium dioxide (E171), macrogol 6000 (E1521), talc (E553b), red iron oxide (E172), yellow iron oxide (E172).
Tablet Appearance
| Strength | Colour | Shape & Size | Imprint |
|---|---|---|---|
| 25 mg | Light pink | Round, approx. 6 mm × 3 mm | F1 on one side, plain on the other |
| 50 mg | Light beige | Round, approx. 8 mm × 4 mm | F2 on one side, plain on the other |
| 100 mg | Beige | Round, approx. 10 mm × 4.5 mm | F3 on one side, plain on the other |
Sitagliptin SUN film-coated tablets are supplied in PA/Alu/PE blister packs with desiccant or in HDPE bottles. Available pack sizes include 28, 56, 90, or 98 film-coated tablets. Not all pack sizes may be marketed in all countries.
Marketing Authorisation Holder
Sun Pharmaceutical Industries Europe B.V., Polarisavenue 87, 2132JH Hoofddorp, The Netherlands.
Frequently Asked Questions
Sitagliptin SUN is used to treat type 2 diabetes mellitus in adults. It belongs to the DPP-4 inhibitor class and works by increasing insulin levels produced after a meal and reducing the amount of sugar made by the body. It can be used alone or in combination with other diabetes medications such as metformin, sulfonylureas, pioglitazone, or insulin, alongside diet and exercise.
The usual recommended dose is one 100 mg film-coated tablet taken once daily by mouth, with or without food. If you have kidney problems, your doctor may prescribe a lower dose of 25 mg or 50 mg. Always take this medicine exactly as prescribed by your doctor and continue with any recommended diet and exercise programme.
Yes, rare cases of pancreatitis (inflammation of the pancreas) have been reported in patients taking sitagliptin. You should stop taking the medication and contact your doctor immediately if you experience severe and persistent pain in the abdomen that may radiate to the back, with or without nausea and vomiting. If pancreatitis is confirmed, treatment with sitagliptin should not be restarted.
No, Sitagliptin SUN should not be used during pregnancy. It is also not recommended during breastfeeding as it is unknown whether sitagliptin passes into breast milk. If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor who will prescribe a suitable alternative treatment for your diabetes.
Sitagliptin SUN contains the same active ingredient (sitagliptin) as Januvia and is considered a bioequivalent generic alternative. Both medicines work in exactly the same way as DPP-4 inhibitors to lower blood sugar in type 2 diabetes. The choice between brand and generic is typically based on cost and availability in your region.
Sitagliptin is generally considered a weight-neutral medication. Unlike some other diabetes medicines (such as sulfonylureas, insulin, or thiazolidinediones) which can cause weight gain, clinical studies have shown that sitagliptin does not typically lead to significant changes in body weight. This weight-neutral profile is one of its clinical advantages in managing type 2 diabetes.
References
- European Medicines Agency (EMA). Sitagliptin – Summary of Product Characteristics. Last updated 2025. Available at: www.ema.europa.eu
- American Diabetes Association (ADA). Standards of Care in Diabetes – 2025. Diabetes Care. 2025;48(Supplement 1).
- Davies MJ, Aroda VR, Collins BS, et al. Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care. 2022;45(11):2753–2786.
- Green JB, Bethel MA, Armstrong PW, et al. Effect of Sitagliptin on Cardiovascular Outcomes in Type 2 Diabetes (TECOS). N Engl J Med. 2015;373(3):232–242.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List, 2023. Geneva: WHO; 2023.
- U.S. Food and Drug Administration (FDA). Sitagliptin Prescribing Information. Revised 2024. Available at: www.fda.gov
- International Diabetes Federation (IDF). IDF Diabetes Atlas, 10th Edition. Brussels: IDF; 2021.
- British National Formulary (BNF). Sitagliptin. National Institute for Health and Care Excellence (NICE). Accessed 2025.
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