This weight loss usually occurs after the prescription has been filled.
While on Farxiga for his diabetes, the patient finds his jeans are looser. He steps on the scale and finds himself four pounds lighter. Naturally, he wonders if the other twenty pounds will follow.
The expectations must be tempered.
Farxiga can cause weight loss, but it’s not a Wegovy or Zepbound type of weight loss. Most of these patients lose a couple of pounds, not a significant percentage of their body weight. The main reason why Farxiga became such a sought after drug has less to do with the bathroom scale and more to do with the heart and kidneys.
Farxiga causes some of the glucose to be excreted in the urine
Farxiga is the brand name for dapagliflozin, which is one of the SGLT2 inhibitor class of medications for diabetes.
The kidneys are responsible for filtering glucose from the blood and returning it to the body. This drug prevents some of that glucose from being reabsorbed into the body; instead, it is excreted during urination.
This lowers blood sugar, without notifying the pancreas to make more insulin, and also causes the body to lose a few calories per day.
It almost sounds like a diet pill: consume calories, lose some of their caloric content through the urine, and watch the pounds melt away. The human body is not that easily deceived. The appetite can increase, and the consumer may not know they’re making up for the lost calories elsewhere.
Research has shown that patients taking the 10 mg dose of dapagliflozin lost, on average, about four more pounds than those on a placebo. Someone could lose eight pounds, and someone might not lose any.
Some of that initial weight loss is water, since Farxiga causes patients to urinate more, particularly at the start of treatment. The weight can come off rapidly for a few days and then plateau; it doesn’t mean the drug has stopped working.
Farxiga is not approved by the FDA for obesity. Prescribing it to a healthy individual because they want to lose weight would be an off-label use, and not a particularly appealing one.
The benefit to the heart was an unexpected finding
Farxiga started its career as a blood sugar lowering agent. Its unexpected finding was that patients on the drug were less likely to be hospitalized for heart failure.
Further trials showed that this drug could slow the progression of kidney disease in some patients.
These findings have resulted in a change of the Farxiga script; a cardiologist might prescribe the drug to a diabetic with no other underlying conditions.
That conversation can be confusing.
“My glucose is normal. Why am I taking a diabetic medication?”
This medication does more than remove sugar. It causes changes in the kidneys’ handling of sodium and water, which reduces the pressure in their filtering units and, in turn, lessens some of the stress on the heart.
A type two diabetic with early kidney disease might be quite happy to lose three or four pounds. Maintaining kidney function is the real prize.
Other diabetes medications might be better at lowering glucose or are otherwise a better fit for a patient’s medical history. Farxiga becomes more appealing when the cardioprotection or renoprotection is also needed.
There is the practical downside of having to urinate more often
A patient who routinely wakes up twice a night to go to the bathroom will probably not enjoy using Farxiga for the first week.
More glucose in the urine leads to water leaving the body with it. The patients may urinate more frequently and feel more thirsty than usual. Taking the drug in the morning might be more convenient than right before going to sleep, assuming that’s the dosing schedule.
For most people, it’s an inconvenience. For an older adult on a diuretic on a hot summer day, it can lead to dehydration.
When rising from a seated or lying position, light-headedness, weakness, dry mouth, or dark urine are worth mentioning to the prescriber. Drinking large amounts of water just to quench one’s thirst is not necessarily the answer for someone with heart failure or kidney disease; they may have specific fluid instructions.
Sugar in the urine could make yeast infections more likely
Genital yeast infections are one of the less enjoyable side effects of this drug.
A woman could have itching or burning sensations, along with possible vaginal discharge. A man may notice redness or swelling around the head of the penis. Those who’ve been plagued by recurrent yeast infections before starting this drug are more likely to find this side effect bothersome.
Most of these infections are easily treated. Repeated infections might lead to discussion on if Farxiga is really the right medication.
Burning sensation during urination, fever, or back and/or side pain may point to a UTI and should be evaluated.
There is the rare but life-threatening infection known as Fournier’s gangrene, which affects the genital and perineal tissues. Severe pain, swelling, redness, fever, or sudden feeling of being very ill requires immediate care. It’s a uncommon complication, but not something to wait and see if it resolves on its own.
A normal glucose reading does not rule out ketoacidosis
The most insidious side effect of Farxiga is ketoacidosis.
Diabetic ketoacidosis typically occurs with extremely high blood sugar levels. SGLT2 medications have been known to cause it in the setting of only mildly or moderately increased glucose. A patient may check their meter, find an acceptable number, and think that the cause of their vomiting must be something else.
Nausea, abdominal pain, vomiting, unusual fatigue, or rapid breathing needs to be brought to a medical professional’s attention.
The risk is increased during illnesses, particularly severe ones, dehydration, fasting, surgery, heavy alcohol use, and sudden discontinuation of insulin. Strict ketogenic diets may also pose a risk to those on SGLT2 inhibitors.
Farxiga is typically stopped at least three days prior to surgery or lengthy procedures, and resumed after the patient has been eating and is stable. Further discussion with the medical team is necessary if the medication needs to be changed or stopped for longer.
It should not be prescribed for type one diabetes due to the increased risk of ketoacidosis.
Is Farxiga likely to cause hypoglycemia?
By itself, rarely.
Farxiga does not force more insulin into the bloodstream. That changes when Farxiga is combined with either insulin or a sulfonylurea medication; both can cause hypoglycemia, and the doses may need to be adjusted once Farxiga is added.
This is why adding this medication is never simply putting another pill next to the breakfast cereal. Kidney function, blood pressure, fluid status, other medications, diet, and infection history can all impact how well this medication works.
This medication may assist a person in losing a few pounds. That’s a real weight loss, just an easy one to overhype.
The patient who lost four pounds but avoided hospitalization for heart failure has gained far more. The same goes for the person whose kidney disease slowed down; Farxiga’s finest hour is most often played out in relative obscurity long before it’s seen in a mirror.
