Oral Medications to Lower Blood Sugar Levels

The first line of defense for most diabetics is diet and exercise. Over time however, diet and exercise alone will often not be enough to lower blood glucose levels to normal range, or acceptable levels.  Doctors will then prescribe oral medications.  There are a wide variety of oral medications on the market today.

To reduce the risk of developing diabetic complications, current recommendations suggest patients try to achieve normal blood sugar levels.  When your doctor prescribes oral diabetes medications, he or she will also suggest that you follow a diabetic diet and exercise for 30 minutes a day at least five days a week.  That’s because the medication will work better in concert with these other therapies.

Over time the effectiveness of these medications tends to decrease.  For example, it is difficult to achieve normal blood sugar levels if you have had diabetes for ten years.   When diabetes medications become less effective, it is not uncommon for your doctor to either switch you to a different medication, or prescribe a secondary oral medication.

Types of Oral Medications

There are basically six types of oral medications available to diabetics today.  These are:

  • Sulfonylureas
  • Biguanides
  • Meglitinides
  • Thiazolidinediones
  • Alpha-glucosidase inhibitors
  • DPP-4 inhibitors

Sulfonylureas – Sulfonylureas act in the body by increasing insulin production in the beta cells of the pancreas.  They are effective in controlling elevated blood sugar levels, and generally have a low incidence of side effects.

Sulfonylureas are not for you if you plan on getting pregnant, if you are pregnant.  They are also not good for people who have liver or kidney issues, or for people who have had serious allergic reactions to sulfa antibiotics.  The most common side effect of Sulfonylureas is low blood sugar.  This risk is exacerbated by drinking.  If you do drink, limit yourself to no more than two drinks per day, and eat something prior to drinking.

Biguanides – Biguanides work by decreasing the amount of glucose the liver produces.  They can also decrease insulin resistance and thereby allow cells to absorb blood glucose more effectively.  Metformin (a biguanide) is the most commonly prescribed drug for type 2 diabetes.  It is very well tolerated by most people and does not cause low blood sugar.  Metformin can also help to lower triglyceride levels.  It has the added benefit of helping some people to lose weight.

The most common side effects (occurring in about 5-30% of patients) are diarrhea, temporary nausea, increased gas, and a metallic taste.  Also people taking metformin may experience a decrease in B12 levels.  This usually does not cause issues, and a supplement can alleviate the issue.  There is a possible serious side effect, lactic acidosis, in which lactic acid builds up in the blood stream.  Your doctor will discuss this possibility with you.  Metformin is also widely prescribed with other drugs as a part of a “combination” therapy when one drug is not enough to bring blood sugar levels to normal ranges.

Meglitinides – Meglitinides work by increasing the amount of insulin produced by the beta cells of the pancreas.  They are prescribed for people with type 2 diabetes who have not been able to achieve normal blood sugar levels, or near normal levels with diet and exercise alone.  These drugs must be taken with meals as they can lower blood sugar if you do not eat immediately.

Side effects of meglitinides include low blood sugar, weight gain, nausea, upper respiratory infections, and joint pain.  If you have liver or kidney issues, these drugs may not be a viable option.

Thiazolidinediones – This class of drugs is also used to lower blood sugar levels.  However, troglitazone (Rezulin) was removed from the US marketplace, due to increased liver problems.  Recently this class of medication has come under increased scrutiny as liver damage may still be an associated risk.  However, the newer thiazolidinediones have not yet been shown to cause damage.  Still, thiazolidinediones are not the first choice of medications available.  Physicians may still prescribe thiazolidinediones if other medications have failed to bring blood sugar levels to normal range.

If your doctor has prescribed this class of medication, you should keep an eye out for side effects which might indicate liver damage.  These include: yellowing of the skin or the whites of the eyes, nausea, vomiting, loss of appetite, abdominal pain, dark urine, and/or fatigue.  If any of these present you should contact your physician immediately.

Alpha-glucosidase inhibitors – These drugs work by preventing the body from digesting carbohydrates and reducing the rate of sugar absorption by the intestines.  Alpha-glucosidase inhibitors are particularly helpful for people who experience high blood sugar levels after eating.  Generally, they are more effective in people whose blood glucose levels are slightly above normal.

If you are taking alpha-glucosidase inhibitors, there is a risk of low blood sugar.  Because of the way the alpha-glucosidase inhibitors work, you need to use glucose-tablets, rather than normal foods, to bring your blood sugar levels back to normal.  Side effects are usually temporary and include diarrhea, excessive gas, and abdominal discomfort.

DPP-4 Inhibitors (Dipeptidyl peptidase-4 inhibitors) – These drugs prevent the breakdown of GLP-1.  This is a compound which occurs naturally in the body and helps to reduce blood glucose levels.  DPP-4 allows GLP-1 to remain active longer and thereby reduces the production of blood sugar, only when levels are high.  It also helps the body to produce more insulin.  DPP-4 inhibitors may also help to lower cholesterol.

These drugs may not be a viable option or if you have kidney problems or are pregnant or planning to get pregnant.  Discuss these with your physician.  Side effects include diarrhea, nausea, flatulence, stuffy/runny nose, sore throat, headache, upper respiratory infection, or sensitivity to light.

When you are initially diagnosed with diabetes, your doctor is likely to prescribe an oral medication, based on your medical history.  He or she may change the medication if you are not reaching your blood sugar level goals.  After a period of time, it is likely that the oral medications will begin to lose their efficacy.  This is normal as the disease progresses.  At this point a second medication is likely to be prescribed.  This is called oral combination therapy and is effective because the drugs prescribed work differently within the body.  Because all medications have the risk of interacting with other medications and supplements you may be taking, it is important to discuss everything you take with your physician.  Don’t forget to include any over the counter items you may take.  Keep your eye out for any side effects and discuss them with your physician.  He or she will tell you if there are any urgent side effects you need to be on the lookout for.  Usually, the most common side effect is hypoglycemia.
Keeping your blood sugar levels normal for as long as possible is very important for type 2 diabetics.  Normal blood sugar levels will prevent or delay the onset of diabetic complications.  Work with your physician to determine what is a normal blood sugar level, and what your targets should be.  Taking an oral medication is one of the best ways to achieve blood sugar levels in the normal range.