Ketoacidosis Risk with Invokana
Invokana (canagliflozin), an SGLT2 inhibitor for type 2 diabetes, carries a risk of ketoacidosis, including euglycemic ketoacidosis where blood sugar stays normal or only mildly elevated. The FDA added a boxed warning in 2015 after 73 cases linked to canagliflozin, dapagliflozin, and empagliflozin from 2013 data.[1] Symptoms include nausea, vomiting, abdominal pain, fatigue, and shortness of breath; it can occur even in patients without prior diabetic ketoacidosis (DKA) history.[2]
How Common Is It?
Post-marketing reports show ketoacidosis in about 0.1-0.7% of Invokana users, based on clinical trials and surveillance. A 2018 study of over 50,000 patients found an adjusted rate of 0.38 cases per 1,000 patient-years for SGLT2 inhibitors, higher than other diabetes drugs.[3] Risk rises with doses above 100 mg daily, insulin use, or surgery.[1][4]
Who Is Most at Risk?
Factors increasing odds:
- Low insulin doses or missed doses.
- Prolonged fasting, low-carb diets, alcohol excess, or dehydration.
- Pancreatitis history, kidney impairment (eGFR <60 mL/min), or type 1 diabetes (off-label use).
- Recent illness, surgery, or pregnancy.
Up to 20% of cases occurred within 1 month of starting Invokana.[2][5]
How Does Invokana Cause Ketoacidosis?
SGLT2 inhibitors block kidney glucose reabsorption, promoting excretion and fat metabolism for energy. This raises glucagon, lowers insulin, and increases ketone production without spiking blood sugar—hence euglycemic DKA. Unlike classic DKA from insulin deficiency alone, Invokana adds osmotic diuresis and volume depletion.[4][6]
What Should Patients Watch For and Do?
Monitor for symptoms and check ketones via urine/blood strips if blood sugar exceeds 250 mg/dL or during illness. Stop Invokana before surgery or fasting; restart only after resuming eating and ketone clearance. Hospitals report cases resolving with IV fluids, insulin, and electrolyte correction within 24-48 hours.[1][2] FDA advises against using Invokana in type 1 diabetes or DKA-prone patients.
Comparisons to Other SGLT2 Inhibitors
Invokana's risk profile matches Jardiance (empagliflozin) and Farxiga (dapagliflozin), all with identical boxed warnings. A 2020 meta-analysis of 38 trials showed no significant difference in DKA incidence (0.1-0.3% across class).[3] DPP-4 inhibitors like Januvia have near-zero risk.
Regulatory and Long-Term Updates
FDA expanded warnings in 2016-2017 based on ongoing data; no major changes since. EMA and Health Canada issued similar alerts. Long-term trials like CANVAS (over 10,000 patients) confirmed low but persistent risk, with no increase in mortality.[5][7]
[1]: FDA Drug Safety Communication: SGLT2 inhibitors
[2]: Invokana Prescribing Information
[3]: Diabetes Care: SGLT2i and DKA risk (2018)
[4]: NEJM: Euglycemic DKA with SGLT2 inhibitors
[5]: CANVAS Trial Results
[6]: JAMA: Mechanism of SGLT2i ketoacidosis
[7]: FDA Label Updates (2017)