Januvia, the brand name for Sitagliptin, is an oral medicine that is used to help control blood sugar levels in patients of type 2 diabetes.

Resulting from the body’s inability to use insulin effectively, type 2 diabetes is the most prevalent form of the disease – about 90% to 95% of 30 million Americans who are diagnosed with diabetes have type 2[1]. It is also considered riskier than type 1. This is because its symptoms are less marked, and often unnoticeable, due to which the disease can remain undiagnosed for years after onset. In a large number of cases, type 2 diabetes is often diagnosed when it starts causing complications.

What Causes Type 2 Diabetes?

The exact cause of type 2 diabetes is unknown, but it is believed that a variety of factors contribute to its development. These include genetics, environmental factors, lifestyle, and a person’s overall health and fitness. This means you are more likely to develop diabetes at some point in life if you have a family history of the disease, are overweight, or remain physically inactive.

Symptoms of Type 2 Diabetes

Following are some of the most common symptoms of type 2 diabetes:

  • Frequent urination
  • Increased thirst and hunger
  • Slow healing of wounds and sores
  • Fatigue
  • Unintentional weight loss
  • Frequent infections
  • Blurred vision
  • Patches of dark skin, particularly on the neck and armpits.

The diagnostic test for diabetes is inexpensive, so make sure to consult a doctor and get yourself tested for the disease if you experience any of these symptoms.

Treatment of Type 2 Diabetes

Diabetes is incurable, but it can be effectively managed with medication and lifestyle changes, most importantly, by staying physically active and eating a healthy diet.

There are several medications available to help patients of type 2 diabetes keep their blood sugar levels in control and Januvia is one of them.

Januvia – Prescription Drug for Type 2 Diabetes

As mentioned above, Januvia is an oral medication that helps to regulate the insulin levels in the body, particularly after eating, in adult patients of type 2 diabetes. However, it is not a first-line medication – Januvia is generally only used when metformin or sulfonylurea fail to provide effective results.

Januvia Mechanism of Action

Sitagliptin, the active ingredient in Januvia, is a dipeptidyl-peptidase-4 inhibitor that helps to control the blood glucose levels after eating.

It blocks the breakdown of the incretin hormones that stimulate pancreas for insulin production after eating. The blocking of their breakdown causes their concentration to increase in the blood, which then will lead to increased production of insulin by the pancreas.

Apart from preventing the breakdown of incretin hormones, sitagliptin also reduces the amount of glucose produced by the liver and the level of glucagon in the blood. Glucagon is a hormone that is responsible for preventing the level of blood glucose from dropping too low.

Limitation of Use

Januvia is not to be used for treating type 1 diabetes or diabetic ketoacidosis. It is also not approved for use among patients younger than 18 years.

Available Dosage Forms and Strengths

Januvia is supplied in the form of oral tablets in 25 mg, 50 mg, and 100 mg strengths.

Dosage of Januvia

While the dosage may vary according to the severity of the disease and other treatments or drugs the patient may be using, a 100 mg tablet of Januvia, once daily, is the prescribed dosage in most cases.

However, patients suffering from moderate to severe renal impairment are given low dosages; 50 mg once a day to patients with moderate renal impairment and 25 mg once daily to those with severe renal impairment.

Since the renal function is a key factor in determining the right dosage, it needs to be assessed both before and during the treatment with Januvia.

How to Take Januvia?

Take the prescribed dose of Januvia orally, with or without food. It is highly important to strictly follow the doctor’s instructions while taking this medicine and do not change the dosage unless prescribed by the doctor. Also, regularly check your blood sugar level to make sure it is within a healthy range.

Januvia is mostly prescribed along with dietary changes and exercise, so make sure you follow the complete treatment plan for better glycemic control.

What to Do If You Overdose on Januvia?

An overdose of Januvia can lead to hypoglycemia i.e. low blood sugar. Seek medical help quickly if you experience extreme weakness, excessive sweating, blurred vision, trouble speaking, severe stomach pain, tremors, and/or seizures.

Things to Consider Before Taking Januvia

Just like with most other medications, a person’s medical history and current health condition need to be considered to determine if Januvia is suitable for them. Therefore, it is important that you tell your doctor everything related to your health. In particular, you should tell your healthcare advisor if you currently have or have ever had any of the following conditions:

  • Heart issues
  • Kidney disease (also share the treatments you are getting for it, particularly if you are on dialysis)
  • Pancreatitis
  • Gallstones
  • High triglycerides

Also, tell your doctor if you are or have ever been addicted to alcohol, are pregnant or planning to get pregnant, or a nursing mother. Pregnant women may need dosage adjustments during every trimester and nursing mothers need to be assessed for the safety of the medicine.  Pregnant women may also be asked to join the Januvia pregnancy registry.

Talk to your doctor about the safety of the drug and potential effects on the baby if you are pregnant or a nursing mother.

Side Effects of Januvia

Although Januvia is an effective anti-diabetic medicine, it can produce some negative effects, like most other medications. Some of the common side effects of Januvia include:

  • Headache
  • Low blood sugar
  • Stuffy or runny nose
  • Sore throat
  • Body pain
  • Cough
  • Ear congestion
  • Fever
  • Sneezing
  • Muscle aches

Most of these effects generally go away on their own, after a few days of starting the treatment with Januvia as your body gets adjusted to the medicine. However, consult your doctor if they become worse or do not disappear after a few days.

Less Common Side Effects of Januvia

Some people may experience the following conditions while taking Januvia:

  • Blurred vision
  • Cold sweats
  • Chills
  • Pale, cool skin
  • Confusion
  • Anxiety or depression
  • Fast heartbeat
  • Dizziness
  • Nausea
  • Shakiness
  • Seizures
  • Loss of consciousness
  • Slurred speech
  • Extreme weakness or tiredness without any apparent reason

While they are not likely to cause any serious complication, it is recommended to report to your doctor, as soon as possible, if you experience any of them.

The medicine may cause an allergic reaction in some cases. Get emergency medical help if you experience any signs of it – swelling in your throat or face, difficulty in breathing, and/or hives.

Some people may also develop a severe skin reaction to Januvia. Signs of the skin reaction include:

  • Fever
  • Sore throat
  • Skin rash that is red or purple and spreads, causing blistering and peeling
  • Discomfort or pain in the skin
  • Burning in eyes

Serious Side Effects of Januvia

Januvia may cause some serious adverse reactions in some patients. Stop taking the medicine and consult your doctor if you experience:

  • Symptoms of heart failure, such as rapid weight gain, swelling or fluid retention in the feet, ankles, or legs, shortness of breath, especially when lying down, and/or unusual tiredness.
  • Symptoms of pancreatitis, mainly severe pain in the upper stomach that spreads to the back, with or without vomiting.
  • A severe autoimmune reaction causing itching, blistering and breakdown of the skin’s outermost layer.
  • Little or no urination
  • Joint pain

Possible Drug Interactions of Januvia

Some medications may affect the functioning of Januvia or the blood sugar level, which is why it is highly important to tell your doctor about all the medicines you are taking or have recently stopped taking, including herbal products and dietary supplements, before starting treatment with Januvia. Tell your doctor about the following medications (while they may not cause any serious effects, it is advised to let your doctor know about them):

  • Levothyroxine
  • Hydrochlorothiazide
  • Lisinopril
  • Furosemide
  • Any other diabetic medicine

Patients using Digoxin, a medicine used to treat heart issues, like atrial fibrillation, needs to be regularly monitored when they are co-administered with Januvia.

Januvia may cause upset stomach, diarrhea, and/or swelling of the legs or hands when used with Avandia (Rosiglitazone); also an anti-diabetic drug.

Important:  It is highly important to strictly follow the dietary instructions and physical activity recommended by the doctor when taking Januvia. This anti-diabetic medicine is only a part of the comprehensive treatment plan and may not provide adequate control over the blood glucose level if other recommended measures are not followed.

Prescription Assistance for Januvia

Januvia (Sitagliptin) is an expensive drug, a month’s supply of 100mg Januvia costs over $400, and hence, is out of reach of a large number of diabetic patients.

However, the manufacturer of the drug – Merck & Co. Inc. – provides the medicine at an extremely low cost under the Merck Patient Assistance Program, also called Merck Helps.

Under the prescription savings program for Januvia, eligible patients can get medicines for as little as $5 for up to 12 prescriptions with up to 90-days supply per prescription. Check out the eligibility criteria for Januvia savings program to see if you can apply for it.

In case you do not qualify for the Merck Helps assistance program for Januvia, you can use the discount card offered by drugs.com to save up to 80% on your prescription medication. You can also talk to your doctor to determine if there are any alternative assistance programs for the drug that you can apply for.

It is expected that Januvia will be available as generic sitagliptin by the end of 2026 – generic medicines are typically available at significantly low costs than their branded versions.

[1] https://www.cdc.gov/diabetes/basics/type2.html