Diabetes is one of the most common chronic conditions and the treatment options are endless. The medications that are available each work differently with their own effectiveness and side effects.

So how does your doctor determine which medication is the best option for you?

Typically, your doctor will assess your condition holistically and make a decision based on a number of factors, such as:

  • Your blood sugar levels
  • How long you’ve had diabetes
  • How active you are
  • Any other health conditions you suffer from
  • Whether you have a fear of needles
  • Your alcohol consumption

It is important that you adhere to your treatment plan and take medication as prescribed. If you don’t take the correct dose and at the right time, you may suffer from side effects, or your medication may not be as effective as it should be. If you suspect that you suffer from diabetes, you should never self-medicate and rather let your doctor make a formal diagnosis and prescribe the right drugs for you.

So, what are my options?

According to a consensus statement of the American Diabetes Association and the European Association for the Study of Diabetes, a tier system is used to prescribe medicines depending on how well the medication has been tested. The tier is divided into steps depending on the patient’s stage of diabetes and how they respond to the lifestyle changes and medicines.

Tier 1:

This includes the most established, effective, and most cost-efficient therapeutic strategies to control blood sugar. This is also the most preferred strategy for patients with type 2 diabetes. The tier is divided into 3 steps.

  • Step 1: These are prescribed at when someone is diagnosed with type 2 diabetes. Apart from a lifestyle change, a mild medication that is well tested, has low and less severe side-effects and is cheap is prescribed.
  • Step 2: A second medication is added when step 1 fails to control blood sugar well enough within 2-3 months of having started step 1.
  • Step 3: When step 2 does not work well enough to achieve the required blood glucose control, injectable insulin is started as step 3. Some medicines may be reduced slowly and then discontinued. A third medication may be added but is not preferred.

Tier 2:

These are less-well tested therapies and are only used under special circumstances. These medicines may have more severe side-effects and are not usually prescribed.


These are not really preferred as their effectiveness in reducing glucose is lower. They also may have limited clinical data and can be more expensive. Under certain circumstances, these may be the appropriate choice for some patients.

Anti-diabetic medication can broadly be categorized into two classes: oral drugs and injectable drugs.

Oral anti-diabetic drugs include these classes:

  1. Sulphonylureas
  2. Biguanides
  3. Thiazolidinediones
  4. alpha-glucosidase inhibitors
  5. DPP-4 inhibitors
  6. SGLT2 inhibitors
  7. Meglitinides
  8. Bile acid sequestrants
  9. Dopamine-2 agonists

Injectable anti-diabetic drugs include:

  1. Insulin preparations
  2. Glucagon-like peptide 1 (GLP1) agonists

Let’s take a closer look at these medications.

Oral anti-diabetic drugs


Glibenclamide (also known as glyburide), Gliclazide, Glimepiride and Glipizide

Sulfonylureas are the oldest classes of oral diabetes medications and have been available since the 1950s.

How it worksThese drugs lower blood glucose by increasing the amount of insulin the pancreas produces.
EffectivenessModerately effective – 1 to 2% point reduction in level of glucose bound to hemoglobin (A1C levels).
Side effectsSigns of low blood sugar, hunger, skin reactions, upset stomach, dark-colored urine.

Serious side effects: cardiovascular risks, hypoglycemia, weight gain.

Doses and timingGlibenclamide: 2.5-20mg daily in 1-2 divided doses
Gliclazide: 40-320mg daily in 1-2 divided doses
Glimepiride: 1-6mg daily in 1-2 divided doses
Glipizide: 2.5-40mg daily in 1-2 divided doses
Precaution (use cautiously or avoid)Use with care if you have hepatic (liver) or renal (kidney) problems or if you are allergic to sulphonylureas. Consult your doctor before taking any other medication, including anything that seems safe such as aspirin, while taking this class of medicines. This is because these can have interactions with other medicines and can cause dangerous side effects.
Pregnancy category (FDA classification*)C

Glibenclamide is category B.

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Metformin is the only biguanide available in the US, and usually the oral treatment choice for type 2 diabetes.

It is also known as an euglycemic agent which means that it may restore the blood sugar to normal or even non-diabetic levels. It helps with weight loss and is the drug of choice for obese patients. It can be taken alone or in combination with other drugs and insulin.

How it worksThis medication reduces the production of glucose by the liver. It also improves how the body responds to natural insulin and decreases the absorption of glucose from the intestines.
EffectivenessVery effective for people with type 2 diabetes. It reduces A1C levels up to 1.5% to 2.0%.
Side effectsLoss of appetite, weight loss, diarrhea, nausea, vomiting, upset stomach, weakness, metallic taste in mouth.

Serious side effects: general feeling of being unwell with severe tiredness, fast or shallow breathing, being cold and a slow heartbeat, the whites of your eyes turn yellow, or your skin turns yellow.

WarningsLactic acidosis may occur in patients with kidney or liver dysfunction, people who take alcohol excessively, have a severe infection or are 65 years or older. Lactic acidosis is a severe and potentially fatal condition where there is a build-up of lactic acid in the body leading to excessive acidity in the body. If you have the following symptoms contact your doctor immediately: nausea, vomiting, unusual muscle pain, stomach pain, rapid/trouble breathing, unusual sleepiness, tiredness, dizziness or feeling cold.
Doses and timing500-850 mg tablet 2-3 times daily.
Precaution (use cautiously or avoid)You should not use metformin if you have severe kidney disease, metabolic acidosis, or diabetic ketoacidosis.

If you need to have any type of X-ray or CT scan using a dye that is injected into your veins (iodinated contrast materials), you may need to temporarily stop taking metformin.

Pregnancy category (FDA classification)B
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Thiazolidinediones used to be widely prescribed, but nowadays only pioglitazone is used. However, this also has been linked with instances of bladder cancer although the evidence was deemed insufficient. However, if you are taking this medication, familiarize yourself aware of symptoms of bladder cancer.

How it worksThese medications improve the way insulin works in the body by increasing the uptake of glucose into muscles, fat, and the liver.
EffectivenessLess effective – 0.5-1.4% point reduction in level of glucose bound to hemoglobin (A1C levels).
Side effectsDiarrhea, nausea/vomiting, upset stomach, muscle pain, headache, sore throat, loss of appetite, back pain, bloating, weakness.

Serious side effects: upper respiratory tract infection, water retention, weight gain, dizziness, fever, abnormal weakness/lack of energy, low white blood cell count, anaemia, hypoglycemia, signs of kidney problems.

Doses and timingPioglitazone: 15-30mg once daily.
Precaution (use cautiously or avoid)These medications may cause or worsen heart failure. Increased risk of becoming pregnant if you are using birth control. It is important to follow any instructions from your doctor about alcohol and other medicines if you are taking these. Make sure that you know what to do if you have fluid retention as fluid retention will increase or lead to heart problems.
Pregnancy category (FDA classification)C (potential risk, better to avoid).
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Alpha-glucosidase inhibitors

Acarbose, Miglitol

These medications are also known as starch blockers. These drugs block the breakdown of starchy foods such as bread, potatoes, and pasta, and they slow down the absorption of some sugars, such as table sugar. You take alpha-glucosidase inhibitors with the first bite of each meal.

How it worksThese medications lower blood glucose by delaying the breakdown of carbohydrates and reducing glucose absorption in the small intestine. They also block certain enzymes to slow down the digestion of some starches.
EffectivenessLess effective – 0.5-0.8% points reduction in level of glucose bound to hemoglobin (A1C levels).
Side effectsFlatulence, abdominal bloating, diarrhea.

Serious side effects: potential link to hepatitis (Acarbose).

Doses and timingAcarbose: 50-300mg daily at 3 divided doses.
Miglitol: 25-100 mg 3 times daily.
Precaution (use cautiously or avoid)Do not use these medications if are at risk of intestinal obstruction, or suffer from diabetic ketoacidosis, chronic intestinal disease, colonic ulceration, or inflammatory bowel disease.
Pregnancy category (FDA classification)B
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DPP-4 inhibitors

Vildagliptin, Sitagliptin, Saxagliptin, Linagliptin

These are newer antidiabetic drugs and usually prescribed to type 2 diabetics who do not respond to metformin and sulfonylureas. They promote insulin secretion but because the mechanism is different, they do not cause hypoglycemia.  These drugs may lead to a reduce appetite and weight loss.