Dapagliflozin (Farxiga) is an oral medicine (the type you take by mouth) used to lower blood sugar in people with type 2 diabetes. Your doctor may prescribe it if:
- You can’t take metformin, considered the main treatment for type 2 diabetes.
- Other diabetes drugs don’t control your blood sugar well enough.
- You also have heart failure.
Doctors also prescribe dapagliflozin for heart failure in people who don’t have diabetes. It can lower your risk for being hospitalized for or dying from heart failure.
It’s also used to treat long-lasting (chronic) kidney disease. The drug can stop your kidney function from getting worse and lower your risk of kidney failure.
Dapagliflozin is sold under the brand name Farxiga. In Canada and the U.K., it’s called Forxiga. No generic version is available in the U.S.
You take it as a pill in doses of 5 and 10 milligrams.
How Dapagliflozin (Farxiga) Works
Dapagliflozin is a type of drug called a sodium-glucose cotransporter 2 (SGLT2) inhibitor. These drugs block a protein in your kidneys called SGLT2. This keeps your kidneys from reabsorbing glucose and sodium from your blood. The extra glucose then leaves your body in your urine.
This lowers your blood sugar. At the same time, it reduces pressure and inflammation in your kidneys. All of this also eases the workload for your heart.
The three conditions these drugs treat -- diabetes, heart disease, and chronic kidney disease -- are all related. High blood sugar can damage your kidneys. Over time, they stop filtering blood as well as they should. This makes your heart work harder to get blood to them.
About 1/3 of people with diabetes have chronic kidney disease. They’re also two to four times more likely than others to get heart failure. And people with heart failure are at higher risk of also getting diabetes.
Other SGLT2 inhibitors include:
- Ertugliflozin (Steglatro)
- Canagliflozin (Invokana)
- Empagliflozin (Jardiance)
Dapagliflozin (Farxiga) and Other Diabetes Medicines
You can take dapagliflozin alone. But pairing it with other diabetes drugs works better for some people. Your doctor may prescribe a medication that combines dapagliflozin with one or more other diabetes drugs in a single pill, such as:
- Metformin (Xigduo)
- Saxagliptin (Qtern)
- Saxagliptin and metformin (Qternmet XR)
What to Expect When You Take Dapagliflozin (Farxiga)
You may not feel any difference after you start taking dapagliflozin, but that doesn’t mean it’s not working. It can start lowering your blood sugar about 2 hours after you take it.
Because of the way dapagliflozin works, you may notice that you’re peeing more often or in larger amounts.
That can lead to dehydration, so make sure you drink enough fluids. Ask your doctor how much you should drink each day. Your fluid needs vary depending on your gender, age, the weather, and more. But eight glasses of water a day is a good place to start. Other liquids like coffee and tea, as well as fruits and vegetables that contain lots of water, also count toward your total.
Peeing more can also lead to lower blood pressure, since you have less total fluid circulating in your blood vessels. Your doctor will monitor your blood pressure to make sure it doesn’t get too low. Low blood pressure can make you feel dizzy or faint.
You might notice that you get dizzy when you stand up from a lying position, especially when you first start taking dapagliflozin. When you get out of bed, stand up slowly. If this continues, call your doctor.
Dapagliflozin is meant to be used along with the healthy diet and exercise plan your doctor recommends. You’ll need to monitor your blood sugar and A1c levels. Know what’s low, normal, and high, and what to do if your blood sugar is too low or high.
You may lose a little weight on dapagliflozin, especially soon after you start taking it. A study looked at people on metformin who also took either dapagliflozin or a placebo (a pill that didn’t contain any medicine). Both groups lost weight. But those who took dapagliflozin lost an average of 6.5 pounds over 6 months, compared to about 2 pounds for the placebo group. Their weight loss was faster in the first few weeks.
Side Effects of Dapagliflozin (Farxiga)
Along with peeing more, another mild side effect of dapagliflozin is a stuffy nose and a sore throat. You might also notice that you’re thirstier. Let your doctor know if these issues bother you a lot or seem serious.
Yeast infections of the vagina or penis are among the more common side effects of the drug. Call your doctor if you notice any of symptoms in your genital area:
- Itching
- Odor
- Discharge
- Redness, swelling, or rash
Urinary tract infections (UTIs) are another possible side effect. Contact your doctor if you have symptoms like:
- An urgent need to pee
- Pain or burning when you pee
- Urine that looks cloudy or dark
- Urine with a strong odor
Get medical help right away if you also have:
- Fever or chills
- Nausea or vomiting
- Back pain
Dehydration can be a side effect of this drug. Rest and drink lots of fluids if you have mild symptoms like:
- A headache
- Thirst or dry mouth
- Peeing less
- Dark yellow urine
Seek medical care right away if you have:
- A fever over 102 degrees
- Confusion
- Fast pulse or breathing
- Fainting or unconsciousness
- A seizure
Low blood sugar (hypoglycemia) can happen when you take dapagliflozin. Keep tabs on your blood sugar and follow your doctor’s instructions for what to do if it gets too low. You need emergency care if:
- Your blood sugar doesn’t go back to normal levels.
- You feel like you’re going to faint.
- You’re confused.
- You pass out.
Allergic reactions aren’t common, but they can happen. Even a mild reaction can turn serious later on, so stop taking dapagliflozin and tell your doctor right away if you have
- A rash
- Itching all over
Get emergency medical care if you have:
- Hives
- Swelling in your face, throat, or tongue
- A hard time swallowing or breathing
Fournier’s gangrene, or necrotizing fasciitis, is a rare infection that damages the tissues between your anus and genitals. It can be very serious, so tell your doctor right away if you have:
- Pain, swelling, or redness around this area
- Fever
- Weakness or tiredness
Ketoacidosis is another serious side effect of dapagliflozin that can happen when your body uses fats instead of sugars for energy. Some monitors let you test yourself for acids called ketones that can build up in your blood when this happens. Call your doctor at once if you notice that you:
- Have sweet-smelling breath
- Are peeing much more than usual
- Feel extremely thirsty
Get medical care at once if:
- You keep throwing up.
- You feel very tired.
- You have a hard time breathing.
Kidney problems. Some people have reported a sudden kidney injury after taking dapagliflozin. Seek emergency care if you notice symptoms like:
- Peeing a lot less
- Swelling of your legs or feet
- Nausea or vomiting
- Confusion
- High blood pressure
- Belly pain
Precautions to Take With Dapagliflozin (Farxiga)
Before you start taking this drug, let your doctor know if you:
- Have an upcoming surgery
- Have any allergies to drugs or other substances
- Take any other medicines, over-the-counter drugs, or supplements
- Are on dialysis
- Drink regularly or binge drink (drink a lot in a short period of time)
- Are on a low-sodium diet
- Have ever had heart failure, urinary or kidney issues, pancreatic disease, low blood pressure, or yeast infections
- Aren’t circumcised
- Are pregnant or plan to get pregnant
- Are breastfeeding or plan to do so
Your doctor may test your blood volume and kidney function before prescribing dapagliflozin. They’ll likely monitor these while you take the medication.
While you’re taking this medication, tell your doctor if you are:
- Sick, especially if you vomit or have diarrhea
- Eating or drinking less than usual
- Sweating a lot more than usual
- Are under intense stress
All of these things can affect your blood sugar level. Your doctor may need to change your medication or dosage.
Medicines that can interact with dapagliflozin include:
- ACE (angiotensin-converting enzyme) inhibitors for high blood pressure, like benazepril (Lotensin), captopril, enalapril (Vasotec), fosinopril, lisinopril, moexipril (Univasc), perindopril (Aceon), ramipril (Altace), and trandolapril (Mavik)
- ARBs (angiotensin receptor blockers) for high blood pressure and heart failure, like azilsartan (Edarbi), candesartan (Atacand), eprosartan (Teveten), irbesartan (Avapro), losartan (Cozaar), olmesartan (Benicar), and telmisartan (Micardis)
- Diabetes drugs like insulin, glimepiride (Amaryl), glipizide (Glucotrol), glyburide (DiaBeta, Glynase), repaglinide (Prandin), sulfonylureas, and tolbutamide
- Diuretics or “water pills,” sometimes used for high blood pressure
- Lithium, which is prescribed for mood disorders
- Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin, ibuprofen, and naproxen
