Is it reasonable to start an elderly female patient with type 2 diabetes, currently taking metformin (biguanide), and with an increased Hemoglobin A1C (HbA1C) from 7.4 to 8.0, on Farxiga (dapagliflozin), a sodium-glucose cotransporter 2 (SGLT2) inhibitor?

Starting Farxiga (Dapagliflozin) in an Elderly Female Patient with Type 2 Diabetes

Yes, starting Farxiga is reasonable and appropriate for this elderly female patient with type 2 diabetes whose A1C has increased from 7.4% to 8.0% on metformin alone. This A1C level indicates inadequate glycemic control that warrants intensification of therapy, and SGLT2 inhibitors like dapagliflozin are well-suited for elderly patients when used with appropriate precautions 1.

Rationale for Adding Dapagliflozin

Glycemic Target Considerations:

• The American Diabetes Association recommends A1C targets of <7.5-8.0% for elderly patients with few comorbidities and intact functional status, and <8.0% for those with multiple chronic illnesses 1.
• An A1C of 8.0% exceeds even the more lenient targets for elderly patients, making treatment intensification appropriate 1.
• The American College of Physicians guidance supports targeting A1C levels of 7-8%, but this patient is at the upper end of this range 1.

Evidence Supporting Dapagliflozin Addition to Metformin:

• Dapagliflozin added to metformin reduces A1C by approximately 0.5-0.8% at 24 weeks, with sustained reductions through 102 weeks 2, 3.
• In the pivotal trial, dapagliflozin 10 mg added to metformin reduced A1C by 0.84% compared to 0.30% with placebo at 24 weeks 2.
• Real-world UK primary care data showed mean A1C reductions of 10.2-12.6 mmol/mol (0.93-1.16%) when dapagliflozin was added to existing therapy 4.

Safety Profile in Elderly Patients

Low Hypoglycemia Risk:

• Dapagliflozin has minimal hypoglycemia risk when used with metformin alone (2-4% incidence, similar to placebo at 3%) 2.
• This is particularly important in elderly patients who are at higher risk for serious adverse effects from hypoglycemia 1, 5.
• The American Diabetes Association specifically notes that medications with low hypoglycemia risk like SGLT2 inhibitors can safely achieve glycemic targets in elderly patients 1.

Additional Benefits Beyond Glycemic Control:

• Weight reduction of 1.1-4.6 kg has been consistently demonstrated, which may benefit overweight elderly patients 3, 4.
• Systolic blood pressure reductions of 4-5 mmHg occur without increasing orthostatic hypotension risk when volume status is monitored 4.
• Cardiovascular and renal protective effects have been demonstrated in SGLT2 inhibitor trials, though elderly patients should be assessed for established cardiovascular disease versus risk factors 1.

Critical Safety Precautions Before Initiation

Volume Status and Renal Function Assessment:

• Before starting dapagliflozin, assess volume status and renal function (eGFR) 6.
• Elderly patients are at increased risk for volume depletion, particularly if on loop diuretics 6.
• Dapagliflozin can be used with eGFR ≥25 mL/min/1.73 m² for glycemic control, though efficacy decreases with declining renal function 6.
• Monitor for signs of hypotension and renal function after initiating therapy 6.

Genitourinary Infection Risk:

• Genital mycotic infections occur in 8-15% of patients versus 5% with placebo 2, 3.
• Urinary tract infections occur in 8-13% of patients 3.
• Educate the patient about symptoms and treat promptly if they occur 6.
• Patients with history of recurrent genitourinary infections require closer monitoring 6.

Diabetic Ketoacidosis (DKA) Risk:

• Although rare, SGLT2 inhibitors can cause euglycemic DKA 6.
• Educate the patient to discontinue dapagliflozin and seek medical attention if signs of ketoacidosis occur (nausea, vomiting, abdominal pain, fatigue) 6.
• Withhold dapagliflozin during acute illness, surgery, or prolonged fasting 6.

Common Pitfalls to Avoid

Do not delay treatment intensification based on the modest A1C increase from 7.4% to 8.0%, as this represents inadequate control requiring action 1.

Do not use dapagliflozin as monotherapy - it should be added to metformin, which this patient is already taking 2, 3.

Do not start dapagliflozin without assessing volume status in elderly patients, especially those on diuretics or with impaired renal function 6.

Do not ignore the need for patient education about genitourinary hygiene, signs of infection, and symptoms of ketoacidosis 6.

Do not assume cardiovascular benefits apply equally - while SGLT2 inhibitors prevent heart failure, their use in patients with established heart failure with reduced ejection fraction requires caution, and GLP-1 receptor agonists may be preferred if atherosclerotic cardiovascular disease predominates 1.

Dosing and Monitoring

Initiation:

• Start dapagliflozin 5 mg once daily, which can be increased to 10 mg daily if additional glycemic control is needed and the medication is well-tolerated 6, 2.
• Dapagliflozin can be taken with or without food 6.

Follow-up Monitoring:

• Recheck A1C in 3 months to assess response 1.
• Monitor renal function and electrolytes within 2-4 weeks of initiation, then periodically 6.
• Assess for volume depletion, orthostatic symptoms, and genitourinary infections at each visit 6.