Sick Day Rules for Diabetes meds: How to Prevent DKA & AKI

When you’re under the weather, the last thing you want is a life‑threatening crisis. Sick Day Rules are a set of evidence‑based steps that tell you how to manage diabetes medicines, fluids, and monitoring when illness strikes. By following these rules you dramatically lower the odds of diabetic ketoacidosis (DKA) and acute kidney injury (AKI), two complications that surge three‑fold during a flu or stomach bug.

Why sick‑day planning matters

Illness puts your body under stress: fever, vomiting, or diarrhea dehydrate you, raise hormone levels, and push blood glucose out of its usual range. A 2022 JAMA Internal Medicine analysis of 47,892 hospital admissions showed a 300 % increase in DKA and a 200 % rise in AKI among people with diabetes during acute illness. In the United States alone, 12.7 % of diabetes‑related hospitalizations stem from medication mishandling on sick days (CDC, 2023). That’s why the American Diabetes Association (ADA) has updated its sick‑day guidance every two years, most recently in January 2023.

Core principles that apply to every diabetes type

• Hydration first: aim for at least 1,500 mL of fluid daily; NICE lowers the threshold to 1,200 mL for high‑risk patients.
• Frequent glucose checks: test every 2-4 hours (minimum six times a day) and keep readings between 100‑180 mg/dL (5.6‑10 mmol/L).
• Ketone vigilance: start urine or blood ketone testing once glucose exceeds 240 mg/dL (13.3 mmol/L).
• Medication review: pause or adjust any drug that can worsen dehydration, lactic acidosis, or ketoacidosis.

Medication‑specific sick‑day rules

Not all diabetes meds behave the same when you’re sick. Below is the most current guidance (ADA 2023, IDF 2022, NICE 2023) for each major class.

Metformin must be stopped at the first sign of vomiting, diarrhea, or fever because rising creatinine (>1.5 mg/dL) makes lactic acidosis 8.3‑times more likely (NEJM 2019). Restart only after fluid intake is back to normal and a doctor confirms kidney function is stable.

SGLT2 inhibitors (empagliflozin, dapagliflozin, canagliflozin) need immediate discontinuation when you can’t stay hydrated. The FDA’s 2021 safety alert linked these drugs to a 7.2‑fold rise in euglycemic DKA under dehydration.

ACE inhibitors and ARBs (e.g., lisinopril, losartan) should be paused if fluid intake drops below 1,500 mL/24 h. A 2022 meta‑analysis showed a 40 % increase in AKI risk when these agents are kept during low‑volume states.

Sulfonylureas (glipizide, glyburide) can cause dangerous hypoglycemia when food intake falls. Reduce the dose by half or hold the drug until you’re eating regular meals again.

Guidelines for newer agents such as GLP‑1 receptor agonists remain vague; most experts recommend continuing them unless you experience significant nausea or vomiting that prevents any oral intake.

Insulin adjustments on sick days

Insulin needs the most careful tweaking because you’re already dealing with fluctuating glucose.

• Type 1 diabetes: increase basal rates by 10‑20 % every 4 hours if glucose stays >15 mmol/L (270 mg/dL). Keep rapid‑acting insulin on hand for correction doses.
• Type 2 diabetes on insulin: individualize the increase; a 2023 Diabetes Care trial found 68 % of participants needed a dose boost, often 10‑30 % higher than usual.

Always have a “15‑15 rule” ready: 15 g fast‑acting carbs every 15 minutes for a low <70 mg/dL that doesn’t respond to a single dose.

Monitoring: glucose, ketones, and kidney function

During illness, your testing schedule tightens. Use a reliable meter and keep at least 50 test strips on hand. Record each reading in a log (paper or app) and note fluid intake.

Ketone testing thresholds:

• Urine ketones > 1.5 mmol/L or blood ketones > 0.6 mmol/L → call your provider immediately.
• If ketones stay elevated after two hours despite hydration, seek emergency care (risk of DKA).

Watch for early AKI signs: reduced urine output, swelling in ankles, or a sudden rise in serum creatinine (>0.3 mg/dL in 48 h). If you notice any, pause ACE/ARB drugs and contact your clinician.

Build a sick‑day kit before flu season

Preparation is half the battle. Aim to assemble your kit by early October.

1. Glucose meter plus at least 50 test strips.
2. Ketone testing strips (minimum 10).
3. 7‑day supply of all diabetes meds (including backup pens for insulin).
4. 7 bottles of 12‑oz sugar‑free beverage (sports drinks, electrolyte packets such as Nuun Hydration).
5. Documentation: a printed sick‑day log, emergency phone numbers, and a list of medication adjustments.
6. Rapid‑acting carbohydrate source (glucose tablets, fruit juice).

Set alarms on your phone to remind you of the 2‑4 hour glucose checks. The ADA’s online Sick Day Planner (updated quarterly) can be printed and tucked into your kit.

When to call a doctor or go to the ER

Even with a solid plan, some red flags demand professional care:

• Blood glucose <70 mg/dL that doesn’t improve after two 15‑g carbs.
• Persistent ketones >1.5 mmol/L for more than two hours.
• Vomiting longer than 4 hours or diarrhea longer than 6 hours.
• Fluid intake <1,200 mL/24 h despite attempts to drink.
• Signs of AKI: swelling, dark urine, or a rapid rise in creatinine.

The ADA’s 24/7 helpline (1‑800‑DIABETES) answers 92 % of calls within three minutes - keep that number saved.

Common pitfalls and how to avoid them

Patients often stumble over contradictory advice from different providers. A 2024 Endocrine Practice study found 41 % received mixed instructions. To stay on track:

1. Ask your primary care doctor and endocrinologist to agree on a single sick‑day protocol.
2. Write down which meds to stop, reduce, or keep - don’t rely on memory.
3. Review your kidney function baseline before flu season; share the numbers with your care team.
4. If you’re over 65 or have multiple comorbidities, involve a pharmacist for medication reconciliation.

Remember the “5‑day rule” quoted by Dr. Robert Gabbay (ADA): restarting a paused medication after more than five days without medical clearance spikes AKI risk by 18 %.