Clinical Cases in Pharmacology Clinical Cases  ·  Endocrinology, Diabetes and Metabolism I  ·  Diabetes Mellitus/Hypoglycemia
Endocrinology, Diabetes and Metabolism I, Case EndoDiabetes-0004 — Diabetes Mellitus/Hypoglycemia

An Off-Label Request in Type 1 Diabetes, and a History That Changes the Answer

The drug class carries a real, trial-confirmed ketoacidosis risk in type 1 diabetes — but her own chart holds a detail that determines whether that risk is abstract or concentrated, and nobody has asked her about it yet.

Abbreviations, terms, and other agents mentioned in this case SGLT2i — sodium-glucose cotransporter-2 inhibitor  ·  T1DM — type 1 diabetes mellitus  ·  DKA — diabetic ketoacidosis  ·  CGM — continuous glucose monitoring  ·  CV — coefficient of variation, a glycemic-variability measure  ·  A1c — hemoglobin A1c
Presentation

Priya N., a 27-year-old woman, keeps four beehives in her apartment building's shared courtyard, a hobby she took up during a rough stretch after her diagnosis and now treats with the same disciplined attention she brings to her insulin pump settings. She has had type 1 diabetes since age 14, is on a hybrid closed-loop pump system with continuous glucose monitoring, and her A1c has run a reasonable 7.4% for the past year — but she's gained nearly nine kilograms since starting intensive insulin therapy in her early twenties, and her glucose trace shows real day-to-day variability she describes as exhausting to manage around her work schedule as a courtroom stenographer. She read about SGLT2 inhibitors online, brought it up directly, and wants to know why it isn't simply part of her regimen already.

What her chart also shows, and what she doesn't raise unprompted, is two documented episodes in the past eighteen months where her care team noted intentional under-dosing of mealtime insulin during particularly demanding trial weeks — a pattern she described at the time as "just cutting corners," not restrictive eating, but one her endocrinologist flagged for follow-up regardless. That history matters directly to the drug she's asking for: SGLT2 inhibitors lower glucose independent of insulin, which means a patient who is intermittently running relatively insulin-deficient can look reassuringly normal on a glucose meter while ketones climb underneath — the defining, dangerous feature of euglycemic diabetic ketoacidosis, and the reason this drug class carries a explicit labeled warning against use in type 1 diabetes that it does not carry in type 2.

Priya N. · 27 Requested consultation
Diabetes history
T1DM since age 14, hybrid closed-loop pump + CGM
A1c
7.4%, stable over the past year
Glycemic variability
CV 41% on CGM download, above the ~36% target threshold
Weight
+9kg since starting intensive therapy; BMI 27
Insulin-dosing history
2 documented episodes of intentional mealtime under-dosing in the past 18 months, during high-stress work periods
DKA history
No prior DKA episodes
Renal function
eGFR 104
Occupation
Courtroom stenographer, irregular high-pressure trial weeks

Weighing a real benefit against a risk that hides behind a normal number

Endocrinologist Opening

I'd decline this, at least today. DEPICT and inTandem, the two major trials of SGLT2 inhibitors added to insulin in type 1 diabetes, both found several-fold increases in diabetic ketoacidosis — and a meaningful share of it was euglycemic, meaning her glucose meter would look reassuring right up until it wasn't. No SGLT2 inhibitor carries a US type 1 indication. What she's describing is real and frustrating, but it's a quality-of-life problem, and DKA is not a symptom I'm willing to trade a quality-of-life gain for.

Clinical Pharmacologist Response

I'd read those same trials less as a blanket warning and more as a risk that's genuinely modifiable. The DKA signal wasn't spread evenly across every enrolled patient — it concentrated around insulin under-dosing, reduced carbohydrate intake, and intercurrent illness. Structured mitigation — ketone meter training, explicit sick-day rules, starting at the lowest studied dose — changes an individual patient's actual risk, not just the population average the trial reports.

I'm not saying dismiss the DKA data; I'm saying the data itself points to exactly which patients carry the concentrated risk, which means it's answerable rather than unknowable — we just need to know whether she's one of them.

Primary Care Physician Final

She is, or she might be, and that's the part neither of you has said out loud yet. Her chart has two documented episodes of intentional insulin under-dosing in the past eighteen months — exactly the substrate that turns "modifiable risk" into a real one. Adding a drug that lowers glucose independent of insulin, in a patient who has already shown a pattern of running relatively insulin-deficient by choice under stress, isn't the same decision as offering it to a type 1 patient without that history.

This doesn't have to be a flat no, and I don't think it should be — but it has to be a different conversation first. Before we talk about SGLT2 inhibitors, I want an honest conversation with her about those two episodes, what was actually happening during those trial weeks, and whether that pattern is still active. That conversation changes what a safe answer even looks like.

Regimen selected
SGLT2 Inhibitor — Deferred, Not Declined
Off-Label in T1DM · Pending follow-up
Held pending a direct conversation about her insulin-omission history; remains a real option once that pattern is understood and, if still present, addressed.
Referral — Diabetes-Focused Behavioral Health
Non-Pharmacologic
Addresses the stress-linked under-dosing pattern directly, independent of whether SGLT2i is ultimately added.
Continuous Glucose Monitoring — Continued, Variability Reviewed
Monitoring
Existing CGM data will be used to distinguish stress-linked insulin gaps from ordinary day-to-day variability at the follow-up visit.
Immediate SGLT2i Initiation — Ruled Out Today
Considered, not adopted today
Premature before her insulin-dosing history is directly addressed; the mitigation strategies proposed depend on knowing whether the underlying pattern is still active.
Where this was left

Agreed: SGLT2i decision deferred to a dedicated follow-up visit, behavioral health referral placed, and Priya given an honest, direct explanation of why the two documented episodes changed the conversation rather than being treated as settled history. She was not upset by this — by her own account, she'd wondered if it would come up.

Not agreed: what threshold of reassurance at follow-up would make the endocrinologist comfortable prescribing. The pharmacologist and primary care physician both indicated they'd be satisfied by a clean behavioral-health assessment and several weeks of unremarkable CGM data; the endocrinologist wanted a longer observation window given the trial safety signal, a difference not resolved at this visit.

Educational content only — a composite teaching case, not a real patient encounter or a substitute for clinical guidance. About These Cases →