Sitagliptin belongs to the group of diabetes medications called DPP-4 inhibitors. It works by increasing the amount of incretin released by the intestine. Incretin is a hormone that raises insulin levels when blood sugar is high and decreases the amount of sugar made by the body. Sitagliptin is used alone or in combination with other medications to improve blood sugar levels in adults with type 2 diabetes. This medication should be used as part of an overall diabetes management plan that includes a diet and exercise program.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual dose of this medication is 100 mg taken by mouth once daily with or without food.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature and keep it out of the reach of children.

25 mg
Each pink, round, film-coated tablet, with "221" on one side, contains 25 mg of sitagliptin. Nonmedicinal ingredients: microcrystalline cellulose, anhydrous dibasic calcium phosphate (calcium hydrogen phosphate, anhydrous), croscarmellose sodium, magnesium stearate, and sodium stearyl fumarate; film coating: polyvinyl alcohol, polyethylene glycol (macrogol), talc, titanium dioxide, red iron oxide, and yellow iron oxide.

50 mg
Each light beige, round, film-coated tablet, with "112" on one side, contains 50 mg of sitagliptin. Nonmedicinal ingredients: microcrystalline cellulose, anhydrous dibasic calcium phosphate (calcium hydrogen phosphate, anhydrous), croscarmellose sodium, magnesium stearate, and sodium stearyl fumarate; film coating: polyvinyl alcohol, polyethylene glycol (macrogol), talc, titanium dioxide, red iron oxide, and yellow iron oxide.

100 mg
Each beige, round, film-coated tablet, with "277" on one side, contains 100 mg of sitagliptin. Nonmedicinal ingredients: microcrystalline cellulose, anhydrous dibasic calcium phosphate (calcium hydrogen phosphate, anhydrous), croscarmellose sodium, magnesium stearate, and sodium stearyl fumarate; film coating: polyvinyl alcohol, polyethylene glycol (macrogol), talc, titanium dioxide, red iron oxide, and yellow iron oxide.

This medication should not be taken by anyone who is allergic to sitagliptin or to any of the ingredients of the medication.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• arm, leg, or back pain
• constipation
• headache
• itching
• muscle pain
• nausea
• sore throat
• stuffy or runny nose
• vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• joint pain
• skin blisters
• symptoms of low blood sugar (e.g., headache, drowsiness, weakness, dizziness, confusion, irritability, hunger, fast heartbeat, sweating, and feeling jittery)
• symptoms of kidney problems (e.g., nausea, loss of appetite, weakness, shortness of breath, passing little or no urine)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• severe skin reaction (blistering, peeling, skin breakdown)
• symptoms of pancreatitis (e.g., prolonged, severe abdominal pain with or without vomiting)
• symptoms of a serious allergic reaction (such as swelling of the face, lips, tongue, or throat; skin rash; hives; or difficulty breathing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Hypersensitivity reaction: A severe allergic reaction called hypersensitivity reaction has occurred for some people with the use of sitagliptin. Stop taking the medication and get immediate medical attention if you have symptoms of a severe allergic reaction, including fever, swollen glands, yellowing of the skin or eyes, or flu-like symptoms with skin rash or blistering.

Immune system: Sitagliptin can reduce the number of cells that fight infection in the body (white blood cells). This side effect may be more of a concern for people who already have a weakened immune system. People who have HIV infection, have had an organ transplant and are taking medications to reduce the activity of the immune system, or are taking medication to treat certain types of cancer are more likely to have a weakened immune system. If any of these conditions apply to you, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: Sitagliptin has been reported to cause decreased kidney function and may cause kidney failure. Your doctor may recommend regular testing to check your kidney function while you are taking sitagliptin. If you notice signs of kidney problems, such as decreased urine production; swelling in your hands, wrists, feet, or ankles; difficulty breathing, or weakness, contact your doctor as soon as possible.

People with decreased kidney function may require lower doses of this medication. If you have kidney disease or decreased kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

This medication is not recommended for people with moderately to severely reduced kidney function.

Liver function: This medication is not recommended for people with severely reduced liver function. People with moderately reduced liver function should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Low blood glucose (sugar): Hypoglycemia (low blood sugar) can occur when sitagliptin is used in combination with metformin and a sulfonylurea (e.g., glyburide, gliclazide), or insulin. If you experience low blood sugar (e.g., headache, drowsiness, weakness, dizziness, confusion, irritability, hunger, fast heartbeat, sweating, and feeling jittery) while taking this medication, contact your doctor.

Pancreatitis: This medication may cause pancreatitis (inflammation of the pancreas). People with a history of pancreatitis, gallstones, alcoholism, or high triglycerides may be more at risk of experiencing this. If you experience prolonged and severe abdominal pain with or without vomiting while taking this medication, contact your doctor immediately.

Type 1 diabetes and diabetic ketoacidosis: Sitagliptin should not be used by people with type 1 diabetes or to treat diabetic ketoacidosis (increased ketones in the blood or urine).

Pregnancy: This medication is not recommended for use during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if sitagliptin passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

Seniors: Seniors are more likely to have decreased renal function and may require lower doses of this medication.

There may be an interaction between sitagliptin and any of the following:

• acetazolamide
• alcohol
• alpha-lipoic acids
• angiotensin converting enzyme inhibitors (ACEIs; captopril, enalapril, ramipril)
• antimalarial medications (e.g., hydroxychloroquine, quinine)
• antipsychotics (e.g., aripiprazole, clozapine, quetiapine, risperidone)
• beta-blockers (e.g., acebutolol, carvedilol, metoprolol, propranolol)
• bismuth subsalicylate
• buserelin
• cancer medications (e.g., belzutifan, bortezomib, vorinostat)
• cephalexin
• cimetidine
• corticosteroids (e.g., betamethasone, dexamethasone, fludrocortisone, prednisolone)
• danazol
• disopyramide
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide)
• diabetes medications (e.g., gliclazide, insulin, repaglinide)
• elagolix
• epinephrine
• estrogens (e.g., conjugated estrogen, estradiol, ethinyl estradiol)
• everolimus
• glucagon
• glycopyrrolate
• goserelin
• hepatitis C antivirals (e.g., glecaprevir, ledipasvir, voxilaprevir)
• HIV integrase inhibitors (e.g., bictegravir, dolutegravir)
• HIV protease inhibitors (e.g., atazanavir, darunavir, ritonavir)
• hydroxychloroquine
• lamotrigine
• leuprolide
• linezolid
• megestrol
• methazolamide
• mifepristone
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• nicotinic acid (niacin)
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., celecoxib, diclofenac, ibuprofen, ketorolac, naproxen)
• patiromer
• pegvisomant
• pentamidine
• progestins (e.g., dienogest, levonorgestrel, medroxyprogesterone, norethindrone)
• protein kinase inhibitors (e.g., ceritinib, nilotinib, sunitinib)
• quinolone antibiotics (e.g., ciprofloxacin, norfloxacin, ofloxacin)
• ranolazine
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
• sirolimus
• somatostatin-like medications (e.g., lanreotide, octreotide, pasireotide)
• somatropin
• "statin" anti-cholesterol medications (e.g., atorvastatin, lovastatin, simvastatin)
• sulfamethoxazole
• tacrolimus
• terbutaline
• testosterone
• topiramate
• tramadol
• triptorelin
• trimethoprim
• verapamil

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.