Diabetes medications can be effective in preventing disruptions in blood sugar levels. However, these medications sometimes cause side effects or do not work well together with other medications.
Discuss with your doctor what to look for. Side effects are varied and may feel like an upset stomach or be complicated by a serious medical condition. Other medications taken may cause the diabetes medication to be ineffective, or they may make it work better.
Different types of diabetes medications have their own side effects, and they interact with other medications in different ways.
Diguanide
Metformin is usually the drug of choice that doctors recommend to treat type 2 diabetes. The drug lowers blood sugar by improving the way the body uses insulin and also lowers the amount of sugar produced by the liver.
What are the side effects? Nausea, gas, bloating, diarrhea, and upset stomach may occur. Usually, these symptoms will go away after a few weeks of medication once the body has adjusted. Taking the medicine while eating will also help these symptoms go away.
In rare cases, metformin may cause severe lactic acidosis. These symptoms occur when there is a build-up of too much lactic acid in the body. Seek immediate medical attention if you experience any of the following symptoms:
- Unusual weakness, fatigue, or drowsiness;
- Difficulty breathing;
- Abnormal muscle pain;
- Sudden stomach upset, such as vomiting.
Is there any conflict with other medications? Some drugs may interfere with some of the enzymes that metformin relies on to work. Your doctor will test your blood sugar and adjust the dose of metformin if you are taking:
- Amiloride;
- Cephalexin;
- Cimetidine;
- Digoxin;
- Procaine amine;
- Ethylaminopyrimidine;
- Quinidine;
- Quinine;
- Renitidine;
- Methotrexate;
- Vancomycin.
Anticholinergic drugs, such as dicyclomine and oxybutynin , may increase the amount of metformin absorbed into the body, a condition that can lead to hypoglycemia.
Sulfonylureas
Including glipizide, glimepiride, and glibenclamide, these drugs lower blood sugar by helping the pancreas produce more insulin.
What are the side effects? The most common side effect is hypoglycemia, which can cause unsteady movement, sweating, dizziness, and confusion.
Severe hypoglycemia can be life-threatening. To prevent this condition, it is important to eat regularly and not skip meals.
Other side effects may be weight gain, dark urine, and upset stomach. Sulfonylureas may also trigger a rash and a reaction to sunlight.
Is there a conflict with other medications? About 100 medications can change the effectiveness of sulfonylureas. Some drugs can increase their effectiveness too much, which can lead to dangerous hypoglycemic symptoms, and others can decrease their effectiveness. Your doctor may need to monitor blood glucose levels closely or adjust the dose of a sulfonylurea.
Medications that may affect the effectiveness of sulfonylureas include:
- Azole antifungals, including ketoconazole and fluconazole;
- Some antibiotics, such as ciprofloxacin, chloramphenicol, sulfonamides, clarithromycin, rifampin, and isoniazid;
- cholesterol-lowering drugs, such as gemfibrozil and clobetrozine;
- Tricyclic antidepressants;
- H2 receptor blockers;
- Gout medications, such as sulfinpyrazone and probenecid;
- Some hypertension medications, including angiotensin-converting enzyme (ACE) inhibitors and bosentan;
- beta-blockers;
- Corticosteroids;
- calcium channel blockers;
- Oral contraceptives;
- Thiazide diuretics;
- Thyroid medications.
Grelinide analogues
Including repaglinide and nateglinide. These drugs help the pancreas produce more insulin. Although these drugs work more quickly, their effects do not last in the body.
What are the side effects? These drugs can cause hypoglycemia and weight gain.
Does it conflict with other drugs? Some drugs can interfere with the body’s absorption of glinides, causing blood glucose levels to be too high or too low. It may be necessary to monitor blood glucose levels closely, adjust the dose of the medication, or change the medication.
Medications that do not work better with glinides include:
- Antifungals of the azole class;
- Some antibiotics, including rifampin and isoniazid;
- Some hypertensive drugs, such as calcium channel blockers, beta-blockers, and thiazide diuretics;
- Corticosteroids;
- estrogens;
- Niacin;
- Oral contraceptives;
- Phenothiazines;
- Phenytoin;
- Thyroid supplements;
- Monoamine oxidase inhibitors;
- Non-steroidal anti-inflammatory drugs;
- Probenecid;
- salicylic acid;
- Sulfonamides.
Thiazolidinediones (TZD) drugs
Including pioglitazone and rosiglitazone. These drugs promote the action of insulin in the body.
What are the side effects? They can cause the body to retain too much fluid and trigger swelling. Thiazolidinediones also cause weight gain and increase levels of low-density lipoprotein (LDL), the “bad” cholesterol. They have also been linked to serious side effects such as fractures and heart failure.
Is there a conflict with other drugs? Some drugs block the enzyme that processes thiazolidinediones. Your doctor may switch to another diabetes medication if you take:
- Fluvoxamine;
- Gefirozil;
- Ketoconazole;
- Rifampicin;
- Methocarbamol.
The following drugs may increase the chance of heart disease if used in combination with TZD:
- Non-steroidal anti-inflammatory drugs;
- Sulfonylureas;
- Nitrates.
α-glucosidase inhibitors
Including acarbose, miglitol. Taking an alpha-glucosidase inhibitor at the beginning of each meal slows down the breakdown of carbohydrates.
What are the side effects? Because the above drugs affect digestion, there may be side effects such as flatulence, diarrhea, and stomach pain.
Does it conflict with other medications? Alpha-glucosidase inhibitors may also not work if digestive enzymes and activated carbon supplements are taken together.
alpha-glucosidase inhibitors can also make it harder for the body to absorb digoxin. This class of drugs may also affect the effectiveness of warfarin. Talk to your doctor if you take this type of medicine.
DPP-4 inhibitors (dipeptidyl peptidase 4 inhibitors)
Including selegiline, saxagliptin, ligliptin, and alogliptin. These drugs help the pancreas release more insulin after a meal and also reduce the amount of sugar produced in the body.
What are the side effects? Symptoms such as sore throat, nasal congestion, upset stomach, and diarrhea may occur.
Does it conflict with other medications? Some medicines can interfere with the absorption of DPP-4 inhibitors in your body. Your doctor will carefully monitor your blood glucose levels and watch for potential side effects if you take:
- Atazanavir and ritonavir;
- clarithromycin and rifampin;
- Diltiazem;
- Ketoconazole.
Concomitant use of ACE inhibitors and DPP-4 increases the chance of floaters.
SGLT2 inhibitors (sodium-glucose co-transport protein 2 inhibitors)
Including carteglichen, dagliflozin, and engramine. These drugs work in the kidneys to remove excess sugar from the blood through the urine.
What are the side effects? These drugs can increase the chance of getting urinary tract and yeast infections, and may also cause a drop in blood sugar.
Does it conflict with other drugs?SGLT2 inhibitors do not usually interact with drugs. Rifampin decreases the effectiveness of the drug, and SGLT2 inhibitors also increase the amount of digoxin build-up in the body.
Insulin
Including glargine insulin, lysine insulin, menthol insulin, glargine insulin, digitonin insulin, and low-argin insulin.
If other medications are not effective, you will need to receive insulin therapy, which uses a needle and syringe or pen syringe to inject insulin.
What are the side effects? The most common side effect is hypoglycemia. There may also be a variety of symptoms, including headache, rash, dizziness, anxiety, cough, and dry mouth. Follow your doctor’s instructions. Some of the symptoms will go away as your body gets used to the medicine.
Is there any conflict with other medicines? Some medicines can affect how well insulin works in the body, causing blood sugar levels to be too high or too low. Your doctor may need to monitor your blood glucose levels closely, adjust your dose, or change your medication if you take some of the following medications:
- Diabetes medications;
- salicylic acid;
- Some antidepressants, such as fluoxetine, monoamine oxidase inhibitors;
- Some antibiotics, including isoniazid and sulfonamides;
- Betablockers;
- Some hypertensive drugs, such as ACE inhibitors and angiotensin II receptor blockers;
- Some cholesterol-lowering drugs, including fibrates and niacin;
- Dextropropoxyphene, hexoketococine, and growth inhibitor analogs;
- Corticosteroids;
- Oral contraceptives;
- Estrogens;
- Diuretics;
- Phenothiazines;
- Danazol;
- Protease inhibitors;
- Glucagon;
- Thyroid medications.