Farxiga (Dapagliflozin) Safety in Older Adults 65 and Over

Why Geriatric Safety Data Matters for Dapagliflozin

Patients 65 and older represent the majority of the heart failure and chronic kidney disease (CKD) population, yet they carry the highest burden of polypharmacy, renal decline, and fall risk. Dapagliflozin prescribing in this group requires attention to these overlapping vulnerabilities rather than a blanket age-based restriction.

In the DAPA-HF trial (N=4,744), 54% of enrolled patients were 65 or older, and 15% were 75 or older [1]. The primary composite endpoint of worsening heart failure or cardiovascular death was reduced by 26% with dapagliflozin versus placebo (HR 0.74 to 95% CI 0.65 to 0.85, P<0.001). Pre-specified age subgroup analyses published alongside the primary results confirmed that this benefit was consistent across patients younger than 65, 65 to 74, and 75 and older [1]. The DAPA-CKD trial (N=4,304) reinforced these findings in the CKD population, with a 39% reduction in the composite of sustained eGFR decline, end-stage kidney disease, or renal/CV death (HR 0.61 to 95% CI 0.51 to 0.72) [2]. Patients ≥65 comprised roughly half that cohort and showed no attenuation of benefit.

The 2022 AHA/ACC/HFSA heart failure guidelines give SGLT2 inhibitors a Class I recommendation for HFrEF regardless of age [3]. The Kidney Disease: Improving Global Outcomes (KDIGO) 2024 guideline similarly recommends dapagliflozin for CKD patients with eGFR ≥20 mL/min/1.73 m² [4]. Neither guideline imposes an upper age limit. The clinical question is not whether older adults benefit. They do. The question is which adverse effects require closer surveillance.

Volume Depletion and Orthostatic Hypotension

Dapagliflozin causes osmotic diuresis by blocking glucose and sodium reabsorption in the proximal tubule, which can lower intravascular volume. In younger patients with intact compensatory mechanisms, this effect is mild. In older adults, reduced baroreceptor sensitivity and age-related decline in total body water amplify the hemodynamic impact.

The FDA label reports volume depletion events (dizziness, orthostatic hypotension, dehydration, syncope) in approximately 1.5% of patients ≥65, compared with 0.7% of patients younger than 65 [5]. A pooled safety analysis of 13 dapagliflozin trials found that the incidence was highest in patients older than 75 who were simultaneously taking loop diuretics [6]. This is not a reason to withhold the drug. It is a reason to proactively adjust the diuretic regimen.

Practical management starts before the first dose. A 2023 consensus statement from the Heart Failure Society of America (HFSA) recommends reducing loop diuretic doses by 25% to 50% when initiating an SGLT2 inhibitor in euvolemic patients [7]. Checking orthostatic vitals at baseline and again at 1 to 2 weeks helps catch early depletion. Patients should be counseled to maintain adequate fluid intake, particularly during warm weather or intercurrent illness.

Renal Function Monitoring in the Geriatric Patient

Age-related nephron loss means that most patients over 75 have an eGFR between 30 and 60 mL/min/1.73 m². Dapagliflozin can be initiated at an eGFR as low as 25 mL/min/1.73 m² for the heart failure and CKD indications and continued even if eGFR falls below that threshold while on therapy [5]. The type 2 diabetes indication requires eGFR ≥45 mL/min/1.73 m² for glycemic benefit, though cardiorenal protection persists at lower values.

An expected "eGFR dip" of 2 to 5 mL/min/1.73 m² occurs in the first 2 to 4 weeks of SGLT2 inhibitor therapy. This dip reflects reduced glomerular hyperfiltration and is hemodynamic, not structural [8]. In the DAPA-CKD trial, the initial dip reversed by week 16, and the long-term slope of eGFR decline was significantly slower in the dapagliflozin group (−1.67 vs. −3.59 mL/min/1.73 m²/year) [2]. Clinicians unfamiliar with this pattern sometimes discontinue therapy prematurely. A decline of more than 30% from baseline or an abrupt drop below 15 mL/min/1.73 m² warrants reassessment, but a modest early dip does not.

The KDIGO 2024 guideline recommends checking serum creatinine and potassium within 1 month of initiation and then every 3 to 6 months [4]. For patients concurrently taking renin-angiotensin-aldosterone system (RAAS) inhibitors and mineralocorticoid receptor antagonists (MRAs), hyperkalemia risk is additive. Serum potassium should be checked at the same intervals.

Genital Mycotic Infections in Older Adults

SGLT2 inhibitors increase urinary glucose excretion, creating a favorable environment for Candida species in the perineal area. Across dapagliflozin trials, genital mycotic infections occurred in approximately 5% to 8% of patients, with higher rates in women than men [6]. Age alone does not significantly increase incidence, but several geriatric factors compound risk: urinary incontinence, limited mobility affecting hygiene, and prior history of candidiasis.

Most infections are mild and treatable with a single dose of oral fluconazole 150 mg or topical azole cream for 3 to 7 days [5]. Recurrent episodes (three or more per year) may warrant drug discontinuation, though this threshold should be weighed against the cardiovascular and renal benefits the patient is receiving.

A 2020 meta-analysis in Diabetes, Obesity and Metabolism (14 RCTs, N=10,681) found that the number needed to harm for genital mycotic infection with SGLT2 inhibitors was 17 [9]. For context, the number needed to treat in DAPA-HF to prevent one primary composite event over 18.2 months was 21 [1]. These two numbers sit close enough that a shared decision-making conversation is appropriate, particularly for patients with a history of recurrent infections.

Diabetic Ketoacidosis: A Low-Frequency but High-Stakes Risk

Euglycemic diabetic ketoacidosis (DKA) is rare with dapagliflozin, occurring at a rate of roughly 0.1% to 0.2% per year across clinical trials [10]. The risk is primarily relevant in patients with type 2 diabetes who are also insulin-dependent, those on very low carbohydrate diets, or during acute physiological stress (surgery, sepsis, dehydration). Standard practice is to hold dapagliflozin 3 to 4 days before scheduled surgery and during any acute hospitalization requiring fasting [11].

Older adults face additional risk because intercurrent illness leading to reduced oral intake is more common in this age group. Caregivers and patients should be educated about the "sick day rules" for SGLT2 inhibitors: stop the medication during vomiting, diarrhea, prolonged fasting, or febrile illness, and restart only after normal eating resumes. The 2020 joint statement from the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) reinforces these sick-day protocols [12].

Blood glucose may remain below 250 mg/dL during euglycemic DKA, which delays recognition. Any geriatric patient on dapagliflozin presenting with nausea, abdominal pain, or Kussmaul breathing should have serum ketones checked regardless of glucose level.

Fracture Risk and Bone Health

Early SGLT2 inhibitor trials raised a signal for increased fracture risk, primarily with canagliflozin in the CANVAS trial [13]. Dapagliflozin has not shown this signal. In the DAPA-HF trial, fracture rates were similar between dapagliflozin and placebo groups among patients ≥65 [1]. The DAPA-CKD trial likewise found no excess fracture risk [2].

A 2021 systematic review and meta-analysis in Osteoporosis International covering 38 RCTs of SGLT2 inhibitors (N=30,384) concluded that dapagliflozin had a fracture odds ratio of 0.96 (95% CI 0.77 to 1.18), consistent with no increased risk [14]. The putative mechanism for canagliflozin's signal (increased parathyroid hormone and phosphate reabsorption) does not appear to apply to dapagliflozin at approved doses.

For geriatric patients with established osteoporosis or a high FRAX score, there is no contraindication to dapagliflozin. Standard fall-prevention measures (home safety evaluation, medication review for sedating drugs, vitamin D repletion, and balance training) should be maintained as part of comprehensive geriatric care.

Drug Interactions and Polypharmacy Considerations

The average adult over 65 takes five or more prescription medications. Dapagliflozin has minimal cytochrome P450 interactions, as it is primarily glucuronidated by UGT1A9 [5]. Rifampin, a potent UGT inducer, can reduce dapagliflozin exposure by approximately 22%, but dose adjustment is not typically required [5].

The clinically relevant interactions are pharmacodynamic, not pharmacokinetic.

Loop diuretics (furosemide, bumetanide, torsemide): Additive volume depletion and electrolyte losses. Reduce loop diuretic dose by 25% to 50% at initiation if the patient is euvolemic [7].

RAAS inhibitors (lisinopril, losartan, valsartan, sacubitril/valsartan): Additive hypotension. Monitor blood pressure at 1 to 2 weeks and adjust antihypertensive regimen if systolic BP drops below 100 mmHg.

Insulin and sulfonylureas (glipizide, glimepiride): Additive hypoglycemia. The ADA Standards of Care 2024 recommend reducing insulin dose by 10% to 20% and reducing sulfonylurea dose by 50% when adding an SGLT2 inhibitor [15].

MRAs (spironolactone, eplerenone, finerenone): Monitor potassium closely. In the DAPA-HF trial, 10.5% of patients were also taking an MRA, and hyperkalemia rates remained low, but real-world polypharmacy is heavier than trial conditions [1].

"In patients over 75 taking more than eight medications, every new drug added should prompt removal or dose reduction of at least one existing drug," per the American Geriatrics Society Beers Criteria® 2023 update [16].

Deprescribing Opportunities When Adding Dapagliflozin

Initiating dapagliflozin in older adults creates a natural inflection point for medication review. The diuretic and glucose-lowering effects of the drug often allow reduction of other agents.

For heart failure patients: the SGLT2 inhibitor's natriuretic effect may permit a lower loop diuretic dose, reducing the risk of diuretic-related hyponatremia, hypokalemia, and prerenal azotemia [7]. This is especially relevant in patients over 75 who are prone to diuretic-induced delirium.

For type 2 diabetes patients: adding dapagliflozin typically lowers HbA1c by 0.5% to 0.7% [5]. If the patient's HbA1c target is less aggressive (e.g., <8.0% per ADA guidance for patients with limited life expectancy or high comorbidity burden), this may allow discontinuation of a sulfonylurea (reducing hypoglycemia risk) or reduction of prandial insulin doses [15].

For hypertension patients: dapagliflozin lowers systolic blood pressure by approximately 3 to 5 mmHg [6]. In patients already near their BP goal, one antihypertensive agent may be able to be removed. Prioritize stopping the drug with the worst side-effect profile in that patient.

When to Avoid or Discontinue Dapagliflozin in Older Adults

Not every geriatric patient is a candidate for SGLT2 inhibitor therapy. Absolute contraindications include a history of serious hypersensitivity to dapagliflozin and dialysis-dependent kidney disease [5]. Relative contraindications in the elderly include recurrent urinary tract infections (although the UTI signal for dapagliflozin is weaker than initially suspected), severe peripheral vascular disease with active lower-extremity wounds, and functional frailty so advanced that the cardiorenal benefits are unlikely to accrue within the patient's life expectancy.

The concept of "time to benefit" (TTB) matters. In DAPA-HF, the Kaplan-Meier curves separated within the first 28 days, and the number needed to treat at 18 months was 21 [1]. This is among the fastest TTBs of any heart failure therapy. Even patients with a projected 1-to-2-year life expectancy may benefit. For patients with an expected survival of less than 6 months, the benefit-risk balance shifts, and deprescribing dapagliflozin becomes reasonable.

Discontinuation should also be considered if a patient develops recurrent DKA episodes, persistent genital infections unresponsive to treatment, or symptomatic hypotension despite diuretic dose reduction. Abrupt discontinuation is safe; there is no rebound effect [5].

Monitoring Checklist for Prescribers

Before starting dapagliflozin in a patient ≥65, confirm eGFR ≥25 mL/min/1.73 m² (for HF/CKD indications) or ≥45 mL/min/1.73 m² (for glycemic benefit in T2D). Review the current diuretic dose, document baseline orthostatic vitals, and check serum potassium if the patient is on RAAS inhibitors or MRAs. At 2 to 4 weeks, recheck blood pressure (seated and standing), serum creatinine, and potassium. Accept an eGFR dip of up to 10% to 15% as expected. At 3 months, reassess eGFR trend, HbA1c (if diabetic), and patient-reported symptoms including urinary or genital complaints. Every 6 months thereafter, repeat metabolic panel, reassess loop diuretic need, and perform a structured medication reconciliation per AGS Beers Criteria® guidance [16].