Farxiga (Dapagliflozin) and Increased Urination
Yes, Farxiga (dapagliflozin) does increase frequency of urination due to its mechanism of action as an SGLT2 inhibitor that causes osmotic diuresis and natriuresis. 1
Mechanism Behind Increased Urination
Dapagliflozin works by:
- Inhibiting sodium-glucose cotransporter 2 (SGLT2) proteins in the proximal renal tubules
- Blocking reabsorption of filtered glucose, promoting glucosuria (glucose excretion in urine)
- Creating an osmotic diuresis effect that increases urine volume 2, 1
The FDA label for dapagliflozin specifically notes that the medication causes "changes in urination, including urgent need to urinate more often, in larger amounts, or at night" as one of the common side effects 1.
Pharmacological Basis
The increased urination with Farxiga occurs through several mechanisms:
- Glucosuria: By inhibiting SGLT2, dapagliflozin reduces reabsorption of filtered glucose, leading to urinary glucose excretion 1
- Osmotic diuresis: The presence of glucose in the urine creates an osmotic effect that pulls more water into the urine 2
- Natriuresis: Dapagliflozin also reduces sodium reabsorption, increasing sodium excretion in urine 1
According to the drug label, after starting dapagliflozin, there is a significant increase in urinary glucose excretion that results in increases in urinary volume 1.
Clinical Implications
Healthcare providers should:
- Inform patients that increased urination is expected and indicates the medication is working 2
- Monitor for signs of volume depletion, especially when initiating therapy 2
- Be particularly vigilant in older adults or those on other antihypertensive medications 2
- Advise patients to maintain adequate hydration while taking this medication 2
Patient Counseling Points
Patients should be advised:
- The increased urination is a normal effect of the medication
- Adequate hydration is important while taking Farxiga
- To report symptoms of dehydration (excessive thirst, dizziness, lightheadedness)
- That the diuretic effect may be more pronounced when first starting the medication
Special Considerations
- The American College of Cardiology notes that while the diuretic effect is most pronounced in hyperglycemic states, some diuretic effect persists even when blood glucose normalizes 2, 3
- This diuretic effect contributes to the cardiovascular benefits seen with this medication, including reduced heart failure hospitalizations 2
- SGLT2 inhibitors like dapagliflozin are unique among heart failure medications as they do not require dose adjustment or up-titration 3
The increased urination with Farxiga is directly related to its therapeutic mechanism and represents the medication working as intended, rather than an adverse effect that needs to be mitigated.