Dr K. here, your virtual pharmacist. Today we will start into a new class of medications to treat type 2 diabetes. We’re going to talk about the DPP-4 Inhibitors (don’t worry, there is no test at the end of this, so you don’t need to know what DPP-4 stands for!). If you want an overview of the DPP-4 Inhibitor class, or any of the other classes of diabetes medications, you can read about them all on my previous post here. Today we’ll be talking about the brand-only medication Januvia.
How does it lower blood sugar: Januvia, and all of the other DPP-4 inhibitors, work in a couple of different ways. This is important because it is like fighting the enemy (Diabetes!) from many different sides, making the battle easier to win. The first thing that Januvia does is helps your body make more insulin. Why is this important? Remember, insulin is the chemical in your body that helps get the sugar out of your blood and into your cells, where it belongs.
After you eat, the sugar from your food enters your blood. At this point, your pancreas is supposed to release insulin into your blood. The insulin helps to “open the door” to your cells so that the sugar in the blood enters them. In some diabetics, the pancreas is not producing enough insulin after a meal. So, Januvia helps the pancreas out after you eat, increasing the amount of insulin that is produced.
Would you believe that there are actually chemicals in your body that make your blood sugars go up!? The chemical that I am talking about is called glucagon. Between meals, and when you are exercising a lot, your body sometimes needs glucose (sugar) in your blood. Remember, sugar is energy. So glucagon helps to release glucose from where it is being stored, so that it can enter the blood and go to parts of the body that need the energy (your brain, muscles, etc). But sometimes the body of a diabetic does not know when enough is enough – glucagon is “working off the clock” and putting sugar in your blood, even when you don’t need it. So, Januvia helps to slow down how much glucagon is produced. This helps to keep your blood sugar at that healthy balance between too little and too much.
The effect on your numbers: With Januvia, we usually expect to see a decrease in your A1c by 0.6-0.9% (for example, an A1c of 9.9 could go down to between 9.0 and 9.3). If you remember from my other blog entries, this is a smaller decrease than we see with the more popular diabetes medications (metformin, glyburide, glipizide, glimepiride, actos, and as I will discuss later – insulin). A good thing about Januvia – it has minimal to no effect on your weight (no weight gain!).
Dosing: Januvia is taken once daily, and can be taken with or without food. Most patients are on a dose of 100 mg. If you have kidney problems, you might need to be on a lower dose. Januvia should not be cut, crushed, or chewed.
Side effects: The minor side effects of Januvia include headache, stuffy or runny nose, sore throat, upset stomach, diarrhea, and upper respiratory infection. Between 1 and 12 % of people on Januvia have experienced hypoglycemia (low blood sugars). This is more common when Januvia is taken with other diabetes medications.
There are a few serious side effects that have been linked to Januvia. Some patients on Januvia have reported serious muscle damage, kidney damage or failure, and severe rash from Januvia. But the most major possible side effect of Januvia is pancreatitis (inflammation of your pancreas). This can be very severe, and may lead to death. Some patients are more at risk for this than others, so you should talk to your doctor about this if you are on Januvia, or starting it for the first time. There is also some discussion out there right now that Januvia might cause pancreatic cancer, but as of now the FDA only warns about pancreatitis. More studies are needed.
Pancreatitis generally starts within the first few months of starting Januvia, or when your dose is increased. A sign of possible pancreatitis is severe stomach pain that does not go away. This pain can be felt in the back as well. You may or may not vomit with pancreatitis. If you experience these symptoms, let your doctor know right away.
Who should not take Januvia: Patients with kidney disease or failure might be able to take Januvia, but the dose needs to be decreased. If you are pregnant or breastfeeding, Januvia is probably not the right medication for you because it has not been studied enough in pregnancy and breastfeeding, so it is unknown how it will affect the baby. Januvia is rated as a pregnancy category B (which is generally considered safe), but the studies have only been done in pregnant animals so far, so keep that in mind. If you have had pancreatitis in the past, you should probably not take Januvia because it has yet to be determined if Januvia can cause pancreatitis to come back again. If you have gallstones, a history of alcoholism, or high triglycerides you should discuss these with your doctor if they are considering Januvia for you.
Drug interactions: Januvia can increase the levels of the drug Digoxin if you are taking the two medications together. If you are taking a thyroid medication, it could cause the Januvia to not work as well. There may be other drug interactions possible that I have not listed here, so always consult with your local pharmacist about any possible drug interactions.
Monitoring: When you are on Januvia, you should check your blood sugar daily and watch for signs of low blood sugar. Your doctor will be doing A1c tests to see how well you are doing in your fight against diabetes. Your doctor should be taking blood occasionally to make sure that your kidneys are working properly. And of course, be watching for those signs of pancreatitis (severe abdominal pain).
Place in therapy for diabetes: Januvia is not usually one of the first medications that we choose for type 2 diabetes. This is because of the high cost (it is not available as a generic yet), the fact that it is still new and there could be severe side effects that we haven’t seen yet, and it does not lower A1c as well as most of our other options (especially metformin, insulin, and the sulfonylureas). But Januvia can be added to other medications, like metformin, to lower blood sugars faster. As always, it is up to you and your doctor to decide which medication is best for you.
If you would like to learn more about Januvia, you can visit the official website here.
As a disclaimer, I am your “virtual” pharmacist, here to provide you with information and answers to questions. However, I am not your local pharmacist and could, in no way, be aware of your specific medical needs. Remember to always check with your medical provider and pharmacist before stopping or starting any new medications. My posts are based on general pharmacy principles and should not considered as your “first opinion” when it comes to your health. Please consult with your doctor and pharmacist about anything regarding your health.