Sulfonylureas are another group of agent used to control blood glucose level. These drugs are only effective in patients who have functioning beta cells. They are not effective for all diabetics and may lose their effectiveness over time with others.

Sulfonylureas are further classified as first-generation or second-generation sulfonylureas.

Use of first-generation sulfonylureas is declining as more effective drugs have become available. Also, they are now thought to possibly cause an increase in cardiovascular death.

Use of second-generation sulfonylureas have several advantages over first-generation, including: safer for patients with renal dysfunction as they are excreted in urine and bile, absence of interaction to many protein-bound drugs, and longer duration of action.

All of sulfonylureas can cause hypoglycemia.

Sulfonylureas: Generic and Brand Names

Here is a table of commonly encountered sulfonylureas, their generic names, and brand names:

ClassificationGeneric NameBrand Name
glyburideDiaBeta, Micronase

Therapeutic Action

The desired and beneficial action of sulfonylureas:

  • Sulfonylureas stimulate insulin release from the beta cells in pancreas. They improve insulin binding to insulin receptors and may actually increase the number of insulin receptors.
  • They are also known to increase the effect of antidiuretic hormone on renal cells.


Sulfonylureas are indicated for the following medical conditions:

  • Sulfonylureas are used as adjunct to diet and exercise for the treatment of type 2 diabetes older than 10 years of age; extended release form for patients older than 17 years of age; adjunct treatment with polycystic ovary syndrome.


Here are the characteristic interactions of sulfonylureas and the body in terms of absorption, distribution, metabolism, and excretion:

OralSlow2-2.5 h10-16 h
T1/2: 6.2-17 h
Metabolism: liver
Excretion: urine

Contraindications and Cautions

The following are contraindications and cautions for the use of sulfonylureas:

  • Allergy to sulfonylureas. Avoid hypersensitivity reactions
  • Type 1 diabetes. These patients do not have functioning beta cells and would have no benefit from the drug.
  • Pregnancy and lactation. Potential adverse effect on the fetus or neonate.

Adverse Effects

Use of sulfonylureas may result to these adverse effects:

  • Hypoglycemia (most common)
  • GI distress (nausea, vomiting, epigastric discomfort)
  • Allergic skin reactions


The following are drug-drug interactions involved in the use of sulfonylureas:

  • Decreased excretion with drugs that acidify urine

Nursing Considerations

Here are important nursing considerations when administering agents to control blood glucose level:

Nursing Assessment

These are the important things the nurse should include in conducting assessment, history taking, and examination:

  • Assess for contraindications or cautions (e.g. history of allergy to the drugs, pregnancy and lactation status, severe renal or hepatic dysfunction, etc.) which are contraindications in the use of these agents.
  • Perform a complete physical assessment to establish baseline status before beginning therapy and to evaluate effectiveness and any potential adverse effects during therapy.
  • Assess orientation and reflexes; baseline pulse and blood pressure; adventitious breath sounds; abdominal sounds and function, to monitor effects of altered glucose levels.
  • Assess body systems for changes suggesting possible complications associated with poor blood glucose control.
  • Investigate nutritional intake, noting any problems with intake and adherence to prescribed diet, to help prevent adverse reactions to drug therapy.
  • Assess activity level, including amount and degree of exercise, which can alter serum glucose levels and dosage needs for these drugs.
  • Monitor blood glucose levels as ordered to evaluate effectiveness of drug and glycemic control.
  • Monitor results of laboratory tests, including urinalysis, for evidence of glycosuria, and renal and liver function tests, to determine the need for possible dose adjustment and evaluate for signs of toxicity.

Nursing Diagnoses and Care Planning

Here are some of the nursing diagnoses that can be formulated in the use of this drug for therapy:

  • Risk for unstable blood glucose related to ineffective dosing of antidiabetic agents
  • Imbalanced nutrition: less than body requirements related to metabolic effects
  • Disturbed sensory perception: kinesthetic, visual, auditory, and tactile related to glucose levels

Implementation with Rationale

These are vital nursing interventions done in patients who are taking sulfonylureas:

  • Administer the drug as prescribed in the appropriate relationship to meals to ensure therapeutic effectiveness.
  • Ensure that patient has dietary and exercise regimen and using good hygiene practices to improve the effectiveness of the insulin and decrease adverse effects of the disease.
  • Monitor nutritional status to provide nutritional consultation as needed.
  • Monitor response carefully; blood glucose monitoring is the most effective way to evaluate dose. Obtain blood glucose levels as ordered to monitor drug effectiveness.
  • Monitor patients during times of trauma, pregnancy, or severe stress, and arrange to switch to insulin coverage as needed.
  • Provide comfort measures to help patient cope with drug effects.
  • Provide patient education about drug effects and warning signs to report to enhance patient knowledge and to promote compliance.


Here are aspects of care that should be evaluated to determine effectiveness of drug therapy:

  • Monitor patient response to therapy (stabilization of blood glucose levels).
  • Monitor for adverse effects (hypoglycemia and gastrointestinal distress).
  • Evaluate patient understanding on drug therapy by asking patient to name the drug, its indication, and adverse effects to watch for.
  • Monitor patient compliance to drug therapy.

Practice Test: Sulfonylureas

Here are some practice questions for this study guide. Please visit our nursing test bank page for more NCLEX practice questions.

1. All of the following are true about sulfonylureas, except:

A. It is indicated for all diabetic patients
B. First-generation sulfonylureas have shorter duration of action than second-generation sulfonylureas.
C. They can increase the number of insulin receptors
D. Some patients develop resistance over time

1. Answer: A. It is indicated for all diabetic patients

It is only indicated for patients with functioning beta cells. Therefore, not all diabetic patients are candidate for this drug. Patients with type 1 diabetes do not have functioning beta cells and would have no benefit from the drug.

2. Nurse Janine is taking care of a diabetic patient for the first time. The patient is on sulfonylureas and was asking about its role in managing diabetes. Which of the following is the correct response?

A. Antidiabetic drugs is the backbone of antidiabetic therapy.
B. It can help cure diabetes together with proper diet and exercise.
C. Antidiabetic drugs are adjuncts to help control blood glucose levels.
D. They work by slowing release of insulin by beta cells, decreasing insulin receptor site sensitivity, and allowing liver release of glucose.

2. Answer: C. Antidiabetic drugs are adjuncts to help control blood glucose levels.


Proper diet and exercise are the backbone of antidiabetic therapy; antidiabetic drugs are adjuncts to help control blood glucose levels.

3. Which of the following is the most common adverse effect of taking sulfonylureas?

A. GI distress
B. Hypoglycemia
C. Skin reactions
D. Heartburn

3. Answer: B. Hypoglycemia

Hypoglycemia is the most common adverse effect of taking sulfonylureas. Other common adverse effects include skin reactions and GI distress.

4. The patient taking glipizide is about to be discharged. Which of the following patient statements indicate that there is a need for additional health teaching?

A. “I can take drugs and skip meals so I can lose excess sugar fast.”
B. “I still need to have exercise because this drug I’m taking is not the ultimate remedy to my health problem.”
C. “I’ll have my private duty nurse take my blood glucose level as instructed by the doctor.”
D. Both A and B

4. Answer: A. “I can take drugs and skip meals so I can lose excess sugar fast.”

It is important for nurses to investigate nutritional intake, noting any problems with intake and adherence to prescribed diet, to help prevent adverse reactions to drug therapy.

5. Which of the following is a first-generation sulfonylureas?

A. Metformin
B. Tolbutamide
C. Glimepiride
D. Pioglitazone

5. Answer: B. Tolbutamide

The first-generation sulfonylureas include chlorpropamide, tolbutamide, and tolazamide. Glimepiride is a second-generation sulfonylurea. Metformin is a biguanide.  Pioglitazone is a thiazolidinedione.

Recommended Resources

Recommended resources and reference books. Disclosure: Includes Amazon affiliate links.

  1. Focus on Nursing Pharmacology – Easy to follow guide for Pharmacology
  2. NCLEX-RN Drug Guide: 300 Medications You Need to Know for the Exam – Great if you’re reviewing for the NCLEX
  3. Nursing 2017 Drug Handbook (Nursing Drug Handbook) – Reliable nursing drug handbook!
  4. Lehne’s Pharmacology for Nursing Care – Provides key information on commonly used drugs in nursing
  5. Pharmacology and the Nursing Process – Learn how to administer drugs correctly and safely!
  6. Pharm Phlash Cards!: Pharmacology Flash Cards – Flash Cards for Nursing Pharmacology

See Also

Here are other nursing pharmacology study guides:

Gastrointestinal System Drugs

Respiratory System Drugs

Endocrine System Drugs

Autonomic Nervous System Drugs

Immune System Drugs

Chemotherapeutic Agents

Reproductive System Drugs

Nervous System Drugs

Cardiovascular System Drugs

References and Sources

References and sources for this pharmacology guide for Sulfonylureas:

  • Karch, A. M., & Karch. (2011). Focus on nursing pharmacology. Wolters Kluwer Health/Lippincott Williams & Wilkins. [Link]
  • Katzung, B. G. (2017). Basic and clinical pharmacology. McGraw-Hill Education.
  • Lehne, R. A., Moore, L. A., Crosby, L. J., & Hamilton, D. B. (2004). Pharmacology for nursing care.
  • Smeltzer, S. C., & Bare, B. G. (1992). Brunner & Suddarth’s textbook of medical-surgical nursing. Philadelphia: JB Lippincott.

Iris Dawn is a nurse writer in her 20s who is on the constant lookout for latest stories about Science. Her interests include Research and Medical-Surgical Nursing. She is currently furthering her studies and is seriously considering being a student as her profession. Life is spoiling her with spaghetti, acoustic playlists, libraries, and the beach.