Source: American Diabetes Association
All oral diabetes medications must be prescribed by a doctor. Your doctor will take into account your lifestyle, physical conditions and personal needs before prescribing any particular drug or combination of drugs.
* Generally, you should not use an oral agent if you have type I diabetes (acarbose may prove helpful to people with type I diabetes). They are usually only prescribed for people with type II diabetes.
* Not everyone with type II diabetes will be helped by oral diabetes medications. Oral medications are more likely to lower blood glucose levels in people who have had high blood glucose levels for less than 10 years, who are normal weight or obese, who are willing to follow a healthy meal plan, and who have some insulin secretion by their pancreas. The drugs work poorly in people who are very thin.
* You should not take a sulfonylurea if your pancreas no longer secretes insulin; if you are pregnant or planning a pregnancy; or have significant heart, liver, or kidney disease.
* During severe infections or major surgery, your doctor may recommend that oral diabetes medications be replaced or supplemented with insulin injections, at least temporarily.
* You should avoid sulfonylurea drugs if you are allergic to sulfa drugs. If this is the case, then metformin may be of some help to you. However, you should not take metformin if you have kidney, heart, or liver disease.
* Oral diabetes medications vary in price. At present, metformin is more expensive than the sulfonylureas. This may affect your choice of drugs.
There can be big differences in timing and duration of action of different oral diabetes medications. For example, both metformin and tolbutamide have a minimal risk of hypogylcemia and may be safest for an elderly person living alone. But other medications, such as chlorpropamide and glyburide, can have longer lasting glucose-lowering effects. Also, different people can also respond differently to the same dose of any oral agent. To evaluate these issues, or if you feel that your oral diabetes medication is not doing what it should be, talk to your health care team.
Cautions for Use. All sulfonylurea drugs increase the risk of hypoglycemia, especially if you skip meals or drink too much alcohol. Be sure to talk to your doctor about the symptoms to watch for and any precautions you need to take while your oral medication. Teach your family and friends the warning signs of hypoglycemia. Together, make a plan of action for dealing with unexpected lows.
Oral agents can have other side effects. For example, they can interact with alcohol to make you feel flushed, nauseated, or have a rapid heartbeat. This is especially true with
chloropropamide. In rare cases, chlorpropamide can cause your body to retain water, causing headache, sleepiness, nausea, and sometimes convulsions. Skin rashes can occur with sulfonylurea use. If you notice any changes in your behavior or your body after starting a course of oral diabetes medications, be sure to tell your doctor.
Drug Interactions. You and your doctor should talk about medicines other than your diabetes medications, either prescription or over the counter, that you are currently taking or might be thinking of taking. Are there any medicines you take when you are coming down with a cold? In bed with the flu? Get a sudden headache? If you take aspirin or thyroid or high blood pressure medicine, medicine to lower blood cholesterol, or cold or allergy remedies, tell your doctor. Sometimes, drugs that are safe by themselves can interact with each other to cause sickness or conditions that can be difficult to diagnose. Some drugs can lower or raise blood glucose levels. This must accounted for so that your blood glucose levels don’t go low or stay too high. What looks likes hypoglycemia may really be caused by a drug interaction and can be mistreated. Many drugs interfere with the way the body uses and eliminates oral diabetes medications. These drugs can indirectly cause hyper- or hypoglycemia.
Looking Ahead. After taking an oral diabetes medication for a while you may find that you can consistently achieve normal fasting blood glucose levels. If you have normal readings for several weeks or months, it’s possible that you can control your blood sugar levels by meal planning and regular exercise alone. Ask your health care team whether they can suggest that you start a trial of diabetes control with no pills – just meal planning and regular exercise. If you do this, make sure to keep monitoring your blood glucose and stay in close contact with your health care team.
There is a possibility that oral medications won’t help you at all. Or they may help, but only for a while. In people who have initial success with an oral diabetes medication, about 5 to 10 percent stop responding within a year. Eventually, at least another 50 percent will stop responding. If oral treatment fails to help you achieve your target blood glucose levels, your doctor may want to add insulin to your diabetes care plan, with or without continuing your oral diabetes medication. You may resist your doctor’s suggestion to start the insulin-and-needles routine, but the reward will be improved blood glucose levels. The risk of hypoglycemia may increase with this treatment plan, until you and your doctor find the right doses. Make sure to pay special attention to instructions and medication techniques and schedules. Write all instructions down until you feel comfortable with the new treatment. Know the symptoms of hypoglycemia, and make sure you know how to treat it in advance.