Oral Medicines for Type 2 Diabetes

Diabetes pills can help to manage your blood sugar. These pills are not insulin. They work to manage your blood sugar in several ways. You may be given a combination of medicines. Always follow your healthcare provider's instructions.

Some pills may put you at higher risk for low blood sugar (hypoglycemia). Watch for symptoms of low blood sugar. Symptoms are listed below. Call your healthcare provider if low blood sugar happens often.

Type of diabetes pills

Biguanides

These pills help control the amount of glucose in your blood. They do this by decreasing the amount of glucose made by your liver and helping your muscles use insulin more effectively. These medicines are usually taken with or after each meal. Possible side effects and other problems include:

• Diarrhea

• Nausea

• Vomiting

• Belly (abdominal) bloating

• Excess gas (flatulence)

• Metallic taste in mouth

• Lower blood vitamin B12 levels from decreased absorption from the GI tract of this essential vitamin

Have your vitamin B12 levels checked regularly if you have used Biguanides for a long time. This is especially important if you have anemia or peripheral neuropathy.

Sulfonylureas

These pills help your body make more insulin. They are usually taken 30 minutes before a meal. Possible side effects include hypoglycemia.

Alpha-glucosidase inhibitors

These pills slow the digestion of sugars and starches. They can help keep your blood sugar from going too high after a meal. Take them with the first bite of each main meal. Possible side effects include:

• Stomach pain

• Diarrhea

• Excess gas (flatulence)  

Thiazolidinediones

These pills help your muscle cells use insulin better. Your healthcare provider may order lab tests to check the function of your liver before prescribing these pills and regularly while you are taking them. Possible side effects include: 

• Weight gain

• Extra fluid in your body and swelling

• Increased risk for heart failure

• Osteoporosis and increased risk for broken bones

Meglitinides

These pills increase your insulin for a short period of time. They are usually taken before meals. Possible side effects include:

• Low blood sugar

• Diarrhea

• Headache 

• Slightly increased risk for heart problems

DPP-4 inhibitors

These pills help lower blood sugar levels in people with type 2 diabetes. They are less likely to cause hypoglycemia, unless you take them with a sulfonylurea. They are taken once a day. Possible side effects include:

• Upper respiratory tract infection

• Stuffy or runny nose

• Sore throat

• Headache

Other side effects are under investigation.

SGLT-2 inhibitors

These pills help lower blood sugar levels in people with type 2 diabetes by increasing the amount of sugar that leaks into the urine. Possible side effects include:

• Urinary tract infections

• Genital infections, especially in women

• Dehydration and low blood pressure

• Increased bone fractures

• Development of keotacidosis while blood sugar is only mildly raised above the target range

Note: The FDA has issued a safety warning for the SGLT-2 inhibitor canagliflozin. Recent studies have shown that this medicine increases the risk of leg and foot amputations. If you are taking this medicine, tell your healthcare provider right away if you have any new pain or tenderness, sores, or infections in your legs or feet. Talk with your healthcare provider before stopping any diabetes medicine. 

Dopamine D2 receptor agonist (bromocriptine mesylate)

These pills help lower blood sugar levels in people with type 2 diabetes. Possible side effects of this medicine include:

• Nausea

• Vomiting

• Fatigue

• Dizziness

• Headaches

Combination pills

These medicines may help keep your blood glucose within your target range. They also help your pancreas make more insulin and may help your muscles use insulin more effectively. Side effects depend on which type of combination you use. Your healthcare provider can tell you more.