In a patient admitted with an acute illness, should linagliptin be continued, and what criteria (e.g., ability to eat, hemodynamic stability, renal function) determine whether to hold or resume the medication?

Linagliptin During Acute Illness Admission

In patients admitted with acute illness, linagliptin should generally be discontinued and replaced with insulin-based regimens, as current guidelines recommend insulin as the standard of care for hospitalized patients with diabetes, with oral agents reserved only for highly selected stable patients. 1, 2

Primary Recommendation

The most recent systematic review of clinical practice guidelines (2025) establishes that basal-bolus insulin regimens are the routine treatment for non-critically ill hospitalized patients 2. While certain guidelines permit continuation of oral antihyperglycemic agents including DPP-4 inhibitors like linagliptin, this is explicitly limited to patients who are:

• Stable and eating regularly
• Well-controlled (recent HbA1c <7.5%, blood glucose <180 mg/dL on admission)
• On low insulin doses (<0.6 units/kg/day if previously on insulin)
• Without renal, hepatic, or hemodynamic instability 2

When to Hold Linagliptin

Absolute Indications to Discontinue:

• NPO status or poor oral intake - The medication requires regular food intake for optimal effect
• Hemodynamic instability - Hypotension, sepsis, or shock states
• Acute kidney injury - Despite linagliptin's primarily non-renal excretion (only 5% renal), case reports document AKI associated with linagliptin, particularly when combined with ACE inhibitors in patients with pre-existing CKD 3
• Severe hyperglycemia (blood glucose >300 mg/dL) - Requires insulin therapy 1
• Critical illness - All critically ill patients require continuous insulin infusion 1
• Moderate-to-severe hyperglycemia (blood glucose 201-300 mg/dL) - Basal insulin with correction doses is indicated 1

Relative Indications to Discontinue:

• Concurrent use of medications that impair autoregulation (ACE inhibitors, ARBs) in the setting of volume depletion 3, 4
• Unpredictable oral intake during acute illness
• Need for tight glycemic control - Insulin provides more predictable and titratable control

When Continuation May Be Considered

Linagliptin may be continued only if ALL of the following criteria are met:

1. Mild hyperglycemia only (blood glucose <200 mg/dL) 1
2. Hemodynamically stable with normal vital signs
3. Eating regularly with predictable oral intake
4. Normal or stable renal function (though no dose adjustment is required even in severe renal impairment per FDA labeling 5)
5. No concurrent volume depletion or hypotension
6. Well-controlled diabetes (HbA1c <7.5%) 2
7. Not on high-dose insulin at home (<0.6 units/kg/day) 2

Even when these criteria are met, add correctional rapid-acting insulin before meals or every 6 hours 1.

Pharmacokinetic Considerations

The FDA labeling provides important context 5:

• Primarily non-renal elimination (85% enterohepatic, only 5% renal)
• No dose adjustment needed in any degree of renal or hepatic impairment
• Long half-life (>100 hours terminal, 12 hours effective accumulation)
• Steady-state reached by third dose

However, this favorable renal profile does not override the clinical reality that insulin provides superior glycemic control and flexibility in the acute care setting.

Critical Pitfalls to Avoid

1. Do not rely on sliding-scale insulin alone - This is explicitly discouraged by all major guidelines 2
2. Do not continue oral agents in patients with unpredictable intake - Risk of both hyperglycemia and hypoglycemia
3. Monitor for volume depletion - Linagliptin may cause natriuresis leading to intravascular volume contraction, particularly dangerous with concurrent ACE inhibitors 3
4. Do not use in critically ill patients - Continuous insulin infusion is mandatory 1

Practical Algorithm

Step 1: Assess blood glucose on admission

• >300 mg/dL → Stop linagliptin, start basal-bolus insulin 1
• 201-300 mg/dL → Stop linagliptin, start basal insulin with correction 1
• <200 mg/dL → Proceed to Step 2

Step 2: Assess clinical stability

• Unstable (NPO, hemodynamically unstable, AKI, critical illness) → Stop linagliptin, start insulin
• Stable → Proceed to Step 3

Step 3: Assess diabetes control

• HbA1c >7.5% or on high-dose insulin at home → Stop linagliptin, start insulin
• Well-controlled → May continue linagliptin with correctional insulin coverage 1, 2

Resumption at Discharge

When transitioning back to outpatient care, linagliptin can be resumed if:

• Patient is eating regularly
• Hemodynamically stable
• Renal function has returned to baseline
• Blood glucose control adequate on oral agents alone or with basal insulin

The default approach for hospitalized patients should be insulin-based therapy, with oral agents like linagliptin reserved as the exception rather than the rule.