Oral Hypoglycemic Medications – Types, Usage and Side Effects

Publish On Type 2 Diabetes By Sandra Wilson

Oral Hypoglycemic Medications Types Usage and Side Effects

What are oral antidiabetic (hypoglycemic) drugs?

These are drugs administered by mouth to help reduce high blood sugar levels in patients with diabetes. The dosage of oral anti-diabetic medications will vary depending on patient specific condition. These drugs are used to treat patients with type 2 diabetes, including patients who cannot respond to diet, exercise and weight loss program. Patients with type 2 diabetes can use hypoglycemic medications to help them control high blood sugar levels.

Hypoglycemic drugs list

The following are the common types of hypoglycemic medications:

  1. Biguanides
  2. Sulfonylureas
  3. Thiazolidinediones
  4. Alpha-glucosidase inhibitors
  5. DPP-4 inhibitors


This is a type of oral hypoglycemic drugs that is used to treat type 2 diabetes. If biguanides are not effective on their own, they can be prescribed with or as an alternative to other medications. This medication works by preventing glucose production in the liver and increasing insulin sensitivity of the body. The common biguanide medication available is metformin. Metformin is used as the first line of treatment in patients with type 2 diabetes, in case exercise and diet did not reduce blood glucose levels. Metformin can be used on its own or in combination with other oral or injectable medications. By increasing the body’s sensitivity to insulin, metformin can help users lose weight. Note that biguanides is not supposed to treat type 1 diabetes.


Metformin should be kept in its original container and be tightly closed. Store the medication away from light and under room temperature.

Side effects

Using metformin to treat type 2 diabetes can lead to the following side effects:

  • Diarrhea
  • Decreased appetite
  • Fast breathing
  • Chills or fever
  • Muscle pain
  • Dizziness
  • Stomach pain


This type of drugs are used for people who cannot produce enough insulin or are resistant to insulin produced by the body.

Examples of sulfonylureas include:

  1. Glyburide
  2. Glimepiride
  3. Glipizide
  4. Tolbutamide

Sulfonylureas drugs are used to treat type 2 diabetes. In type 2 diabetic patients they cannot properly use the insulin hormone. Sulfonylureas medication works by increasing the amount of the natural hormone insulin. Insulin is responsible for lowering blood sugar levels in people with diabetes.

It is usually prescribed when exercise, diet or weight loss is not effective in keeping the blood sugar levels at an appropriate range. Taking sulfonylureas as well as adopting a healthy lifestyle can help you reduce the risk of developing serious health complications such as kidney problem, nerve damage, and heart disease. This type of medications should not be used with people who have type 1 diabetes or have diabetic ketoacidosis.

Side effects

Your doctor will prescribe this medication because they believe the benefit of taking it outweighs the risk. However, you may still experience the following side effects which may go away after using this drug for a while. You should contact your doctor immediately in case you have difficulty breathing, hives, seizures and swelling of tongue, face and throat.

  • Weight gain
  • Stomach upset
  • Dark colored urine
  • Skin reactions
  • Headache
  • Hypoglycemia is a common side effect associated with using long acting sulfonylureas.


Thiazolidinediones, also known as glitazones are oral hypoglycemic drugs that are used to treat type 2 diabetes. This medication is an oral hypoglycemic medication that is taken once or twice daily with or without food to reduce insulin resistance in type 2 diabetic patients. TZDs is usually administered after other anti-diabetic medicines such as metformin and sulfonylureas, have failed to reduce blood glucose levels into a target range. Thiazolidinediones works by reducing insulin resistance of your body so that it can effectively manage the blood glucose levels. In addition, glitazones can help you reduce blood pressure and increase the level of HDL cholesterol.

Side effects

In case you are experiencing side effects as a result of taking this medication, you should call your doctor. You should not stop taking this medication without informing your doctor.

  • Headaches
  • Sore throats
  • Muscle pain
  • Weight gain
  • Runny nose

Alpha-glucosidase inhibitors

Alpha-glucosidase inhibitors refers to oral medications that is used to treat type 2 diabetes. Alpha-glucosidase is an enzyme which helps to break down glucose, carbohydrates into glucose that is small in size, so that it can be absorbed. It is used in diabetic patients who have difficulty controlling blood sugar levels after meals. This medication is different from other diabetes drugs in that it doesn’t have any effects on insulin sensitivity or secretion. Alpha-glucosidase inhibitors works by preventing the digestion of carbs such as starch. As a result, it helps to reduce post meal blood sugar levels. This medication slows down carbohydrates digestion and delay absorption of glucose. This medication is supposed to be taken at the start of the meal to achieve the best effect.

Side effects

Alpha-glucosidase inhibitors may lead to gastrointestinal side effects such as:

  • Diarrhea
  • Flatuence
  • Pneumatosis cystoides intestinalis

DPP-4 inhibitors

Dipeptidyl peptidase 4 or DPP 4 inhibitors refers to a class of drugs which helps to lower blood sugar levels in people with type 2 diabetes. This medication is used by people who do not respond well to other medications such as sulfonylureas and metformin. When we make incretin, an enzyme known as dipeptidyl peptidase 4 or DPP-4 eliminates it from the body. This is a normal process for people with diabetes. However, there are some people who have type 2 diabetes that don’t produce enough incretin.

Dpp-4 inhibitor medicine works by blocking the action of the enzyme DPP-4 which destroys incretines (gastrointestinal hormones). Incretin is a natural occurring hormone which is made in the body. Incretines stimulate the pancreas to produce insulin after we eat and reduce glucagon production by the liver. This helps to regulate blood sugar levels. In addition, these hormones reduce appetite and slows down digestion.

Side effects

  • Nausea
  • Diarrhea
  • Stomach pain
  • Skin reactions
  • Headache
  • Sore throat

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.