Glyburide

So the last time you were at your doctor's office, they told you that you have diabetes and started you on metformin.  You went home and started taking it, and tried to improve your diet and exercise.  Now you are back in the clinic for your first lab tests.  The doctor checks your A1c and it is still not to where it needs to be (less than 7% is the goal).  So what do we do?  Since so many problems can come from diabetes that is not under control, your doctor is going to want to start you on another medication quickly to bring your numbers down faster.

Which medication will they choose?  The American Diabetes Association, as well as other medical organizations, have come up with a "roadmap" of how to treat diabetes using medication.  From my blog last week on diabetes, you know that metformin, combined with lifestyle changes in diet and exercise, is our starting point on the journey.  If your A1c is not low enough at the next visit, doctors have three main options: insulin, sulfonylureas, or TZDs.  If you need a refresher on these categories, or if you are tuning into my blogs for the first time, please read my blog on the different classes of diabetes medications here.

Each option has its own pros and cons, but I'm going to start with the sulfonylureas, since they are the least expensive and most common options, second to metformin.  The first sulfonylurea I'll be covering is glyburide, which also goes by brand names DiaBeta, Micronase, and Glynase.

How does it lower blood sugar: Glyburide helps your body release insulin into the blood.  Remember, insulin is the hormone in your body that helps take the sugar out of your blood and puts it into your cells.  So glyburide puts the insulin where it needs to be - in the blood where your sugars are.  In a very small way, glyburide also makes your cells more sensitive to insulin ("opening the door of the cell" for sugar to enter), but this is not the most consistent way that glyburide works.  Unfortunately, as type 2 diabetes progresses, the body sometimes can no longer make its own insulin.  At that point, glyburide is no longer effective because there is no more insulin there to "move."  But in newly diagnosed type 2 diabetics, glyburide can be very effective.

The effect on your numbers: Like metformin, glyburide also lowers your A1c by about 1 - 2% (a patient with an A1c of 9 could go down to an A1c of 8 or 7 when on glyburide).  Glyburide really doesn't seem to lower a patient's cholesterol levels, which was a benefit that we saw with metformin.

Dosing: Glyburide is usually taken once daily, in doses from 2.5 to 20 mg.  Usually patients are started at 2.5 or 5 mg daily and then increased as needed.  Just like with metformin, your doctor can change your dose every 1-2 weeks if needed.  Glyburide should always be taken with the first meal of the day (within about 30 minutes before).  It is important to always take glyburide with food because otherwise the medication will cause your blood sugar to drop too low (hypoglycemia).  So it's important to state again, always take glyburide with food.

Side effects: Hypoglycemia (dangerously low blood sugar) is one of the most dangerous side effects.  Weight gain can also be a possibility with glyburide (obviously not ideal in most diabetics).  Glyburide is the medication in this class with the most likelihood of these side effects, since it takes the longest to leave your body once it is in there.  The other side effects you might have from glyburide are a feeling of stomach fullness (as if you've just finished eating a big meal), heartburn, rashes/itching, and nausea.  Very rarely, glyburide can cause liver problems (hepatitis).

Who should not take glyburide: Any patients with a "sulfa" allergy should not take glyburide, or any other sulfonylureas (which I will be covering in the next few weeks), because they contain the thing that you are allergic to.  Because of the risk of low blood sugar if not taken correctly, anyone that has a very inconsistent diet or has a history of low blood sugar episodes might not be an ideal candidate for this medicine.  Glyburide should not be used in any patient that is pregnant or breastfeeding.  Also, if you have severe liver or kidney problems, your doctor will avoid using this class of medications.

Drug interactions: The most important thing that I want to stress here is that alcohol must be avoided when taking glyburide.  A simplified way to look at it is that glyburide causes your body to not tolerate alcohol.  You could experience side effects such as nausea, flushing of the skin, vomiting, shortness of breath, and very low blood pressure.   But the most important thing that happens is that it can increase the effect of low blood sugar, which can be very dangerous.  Other medications that can interact with glyburide and make it work better or worse are certain blood pressure medications, diuretics ("water pills"), blood thinners, salicylates (like aspirin), and certain antidepressants.  Remember, check with your local pharmacist or doctor before starting any new medications, both prescription and over-the-counter.  And make sure your pharmacy is aware of all medications that you take so that your pharmacist can check for drug interactions when you come in with a prescription.

Monitoring: Just like with metformin, your doctor is going to monitor your A1c, and you will need to monitor your blood sugar levels daily.  Because of the chance of low blood sugars with this medication, you need to be even more consistent with monitoring your blood sugars, and watching if they are too low.  Signs of low blood sugar include feeling like your heart is racing, headache, confusion, increased sweating, hunger, shakiness, tingling in the mouth, and a feeling of anxiety.

If you start to experience any of these, or if you just don't "feel quite right," check your blood sugar immediately.  You will need to have a snack available right away to eat that contains at least 15 grams of carbohydrates, in order to raise your blood sugar to a safe level immediately.  A list of these types of snacks, as well as other information about hypoglycemia can be found here.  I've copied the list over for your reference, to make it easier:

• 4 oz (1/2 cup) of juice or regular soda
• 2 tablespoons of raisins
• 4 or 5 saltine crackers
• 4 teaspoons of sugar
• 1 tablespoon of honey or corn syrup

Choose what will work for you.  Read labels and find something that is appropriate for your  lifestyle.  It needs to be something that is readily accessible by anyone, especially if you are not feeling well enough to get to it.  Remember, regular soda is needed here, not diet.  When we are trying to raise blood sugar quickly, we need to have sugar, not something that is "diabetes friendly."

Once you've had your 15 grams of carbs, you still need to eat a meal containing complex carbs that will help your body get back up to a normal level.  The foods I just mentioned are simple carbohydrates - your body processes them quickly, your blood sugars rise quickly, and then they are gone.  Complex carbs are things like vegetables, brown rice, whole grain breads, and wheat pasta.  Don't stop with just the 15 gram snack or you might be in the same low blood sugar situation within a few hours.

Place in therapy for diabetes: Glyburide is considered one of the first or second choices for treating type 2 diabetics (second usually to metformin).  This is because it is inexpensive, not a shot like insulin is, and only has to be taken once or twice a day.  It is important to mention that some patients just don't see any results with glyburide, or the other medications in this class, so we try it and then have to switch to something else.  As diabetes progresses and your body changes, sometimes glyburide (and any of the other diabetes medications taken by mouth) does not work as well.  About 5-10% of diabetics every year have this happen.  If it does, we can sometimes switch you to another medication within the same class.  Next week I will be talking about another one within this class, so don't miss it!

In case you are curious and want to know more about glyburide, you can find more information here.

If this turns out to not be the right drug for you, don't worry.  As you will see, we have plenty of options.  And as Phil has talked about, you do not have to be a "victim" of diabetes.  You can make changes in your own life that will help to fight back the disease.  They won't cure it, but they will make our medications much more effective, and will keep you living the healthy and happy life that you deserve.  I'm thinking about you, each and every one of you, and wishing you all the best in your fight!  Keep up the good work!

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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.