Breaking Down the Most Common Oral Diabetes Medication

• Oral diabetes medication is prescribed to patients with type-II diabetes mellitus and is considered a non-insulin option to manage blood sugar levels. There are a variety of oral antidiabetic agents, and they can be used singly or in combination with insulin as follows: Sulfonylureas, Thiazolidinedione Drugs, Metformin, Alpha Glucosidase Inhibitors, Meglitinides, and DPP-4 Inhibitors. 
• There are several things nurses must take into consideration when prescribing oral diabetes medication. 
• Education is imperative for patients to fully understand how to safely take antidiabetic medications.   

Oral diabetes medication is prescribed to patients with Type 2 diabetes mellitus and is considered a non-insulin option to manage blood sugar levels.

There are a variety of oral antidiabetic agents, and they can be used singly or in combination with insulin as follows: Sulfonylureas, Thiazolidinedione Drugs, Metformin, Alpha Glucosidase Inhibitors, Meglitinides, and DPP-4 Inhibitors. 

Various Types of Oral Diabetes Medication

Sulfonylureas: These include first-generation and second-generation sulfonylureas, which directly stimulate the pancreas to release insulin.    

 First-generation sulfonylureas include: 

• Tolbutamide 
• Chlorpropamide 
• Tolazamide 
• Acetohexamide

Second-generation sulfonylureas include: 

• Glibenclamide 
• Glipizide 
• Gliclazide 
• Glimepiride  
• Gliquidone. 

 The second-generation sulfonylureas are more potent and more commonly prescribed. 

 The most common and serious adverse effect of oral antidiabetic agents is hypoglycemia. The chances of hypoglycemia increase if the patient is on combination therapy with more than one antidiabetic drug. 

 Adverse effects specific to sulfonylureas include: 

• Photosensitivity 
• Nausea 
• Fluid retention  
• Hyponatremia  
• Epigastric discomfort   
• Blood abnormalities  
• Rash   

Thiazolidinedione Drugs: This class includes the drugs pioglitazone and rosiglitazone. These work primarily by increasing insulin sensitivity by exerting their effects on muscle, adipose tissue, and the liver. Thiazolidinediones also act on the liver to decrease glucose production to some extent. 

The adverse effects specific to thiazolidinediones include: 

• Weight gain 
• Edema 
• Congestive heart failure 
• Fractures 

Metformin: Metformin is commonly prescribed for Type II diabetes mellitus. It is also used in the following conditions: 

• Prevention of type II diabetes mellitus 
• Polycystic ovarian syndrome 
• Gestational diabetes mellitus 

Metformin decreases the production of glucose in the liver and its absorption from the intestines. It also increases insulin sensitivity. 

Its adverse effects include:

• Lactic acidosis: a rare but severe adverse effect of metformin therapy. The mortality rate is high, and 50% of patients developing lactic acidosis die. Symptoms include hyperventilation, myalgia, malaise, and drowsiness. Clinically, the lactate levels are high — greater than 5 mmol/L, decreased blood pH, and electrolyte abnormalities. 
• Metallic taste  
• Nausea  
• Vomiting  
• Abdominal discomfort 

Alpha Glucosidase Inhibitors: The drugs acarbose and miglitol come under this class and inhibit enzymes, thereby reducing intestinal absorption of glucose. 

The adverse effects of acarbose include: 

• Abdominal pain 
• Diarrhea 
• Bloating 

Meglitinides: This class includes the drugs Repaglinide and Nateglinide, which stimulate the release of insulin from the pancreas.  

The adverse effects of these drugs can include: 

• Hypoglycemia 
• Weight gain 

DPP-4 Inhibitors: Dipeptidyl peptidase-4 or DPP-4 inhibitors, also known as gliptins, include drugs such as sitagliptin, saxagliptin, linagliptin, and alogliptin. 

These inhibit the DPP-4 enzyme. This enzyme breaks down intestinal hormones called incretin, which stimulates insulin release. By inhibiting the DPP-4 enzyme, incretins are not destroyed, which promotes insulin release. 

The adverse effects of these drugs may include: 

• Headache 
• Nasopharyngitis 
• Dizziness 
• Nausea 
• Arthralgia 
• Constipation

Nursing Considerations for Oral Diabetes Medication

If your patient is receiving oral diabetes medication, keep in mind the following:

• Prescribe sulfonylureas 30 minutes before their morning meal for once-daily dosage, and if they are to be given as a twice-daily dose, administer 30 minutes before morning and evening meals. 
• Give metformin with morning and evening meals. 
• Monitor liver enzymes for patients taking thiazolidinediones. For the first year of therapy, liver enzymes should be monitored every two months and periodically after the first year. 
• Hypoglycemia is the most common adverse effect of oral antidiabetic drugs and should be treated with oral administration of a rapid-acting carbohydrate. For unconscious patients, glucagon or IV glucose can be administered. Once the patient is awake and can swallow, a complex carbohydrate snack should be given. Also determine the cause of the episode to prevent future occurences.  
• The risk of hyperglycemia is higher during stress, such as infection, surgery, fever, or trauma. In such situations, the patient might need insulin therapy. Monitor the blood glucose level, especially for hyperglycemia. 
• Before starting metformin, check that the patient has not received IV contrast dye in the past 48 hours. Know that lactic acidosis is a rare but severe adverse effect of metformin therapy that can be precipitated in patients with liver disease, alcoholism, dehydration, sepsis, and those who have received IV contrast dye.

Patient Teaching

When your patient is receiving oral antidiabetic drugs, counsel and teach them the following: 

• The therapy must be continued for life. There is no cure for diabetes. However, it can be treated with medications and insulin. Proper adherence to the prescribed drugs can effectively control blood sugar levels. 
• With oral diabetes medication, the patient should also adhere to a healthy diet. Enroll in a weight loss program if needed. Advise daily physical activity. 
• Teach the patient about the complications of diabetes and how to prevent them. Encourage them to maintain good personal hygiene and contact their healthcare provider if they notice signs of any infection. 
• Tell the patient how to monitor their blood sugar levels. Educate them about the signs and symptoms of hypoglycemia and hyperglycemia and how to manage both conditions. 
• Advise the patient to not alter the dose of the medication prescribed to them. 
• Avoid alcohol consumption when taking antidiabetic drugs. 
• Wear medical identification at all times. 

The Bottom Line

Various oral diabetes medications are used to manage Type II diabetes. They can be used as a single agent or in combination with others. Hypoglycemia is the most common and serious adverse effect of these drugs. Counsel patients to report to the hospital if they notice adverse effects and to report these in a timely manner.  While oral antidiabetic agents can be useful and effective, they can have adverse effects that must be attended to in a timely manner. 

Read More