A patient who was taking insulin glargine (Lantus) 22 units daily stopped for three months and now has fasting glucose around 200 mg/dL; should the full dose be resumed at once or restarted at a lower dose and titrated?

Resuming Insulin Glargine After a 3-Month Gap

Resume the full 22-unit dose immediately—do not titrate gradually—because basal insulin requirements do not change simply from stopping insulin, and the patient's current hyperglycemia (glucose in the 200s mg/dL) demands immediate adequate basal coverage. 1

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Why the Full Dose Should Be Resumed

• The patient's basal insulin requirement is determined by their underlying insulin resistance and beta-cell function, not by whether they have been taking insulin recently 1
• A 3-month gap without insulin does not reduce the physiological need for basal insulin; it only allows hyperglycemia to worsen 1
• Fasting glucose in the 200s mg/dL indicates complete inadequacy of endogenous basal insulin production and requires immediate restoration of the previous effective dose 1
• The American Diabetes Association guidelines recommend starting basal insulin at 0.1–0.2 units/kg/day for insulin-naive patients, but this patient is not insulin-naive—they were previously controlled on 22 units, which represents their established requirement 1

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The Danger of Gradual Titration in This Context

• Starting at a lower dose (e.g., 10 units) and titrating upward by 2–4 units every 3 days would require 3–4 weeks to return to 22 units, prolonging exposure to severe hyperglycemia 1
• Prolonged hyperglycemia (glucose >200 mg/dL for weeks) increases the risk of long-term microvascular and macrovascular complications 1
• Gradual titration is designed for insulin-naive patients to minimize hypoglycemia risk, but this patient has a known tolerance for 22 units without hypoglycemia 1

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Monitoring and Safety Considerations

• Check fasting glucose daily for the first week after resuming insulin to confirm the dose is appropriate 1
• If fasting glucose remains ≥180 mg/dL after 3 days on 22 units, increase by 4 units every 3 days until fasting glucose reaches 80–130 mg/dL 1
• If fasting glucose falls <70 mg/dL, reduce the dose by 10–20% immediately and reassess 1
• Target fasting glucose: 80–130 mg/dL 1

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When Gradual Titration Would Be Appropriate

Gradual titration is only indicated in the following scenarios, none of which apply here:

• Insulin-naive patients starting basal insulin for the first time (start at 10 units or 0.1–0.2 units/kg/day) 1
• High-risk patients (age >65 years, renal impairment, poor oral intake) who require lower starting doses (0.1–0.25 units/kg/day) 1
• Patients transitioning from IV insulin or recovering from diabetic ketoacidosis, where insulin sensitivity may be temporarily altered 1

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Common Pitfall to Avoid

• Do not treat this patient as insulin-naive simply because they stopped taking insulin for 3 months 1
• The 22-unit dose was previously effective, and there is no physiological reason to expect increased insulin sensitivity after a period of uncontrolled hyperglycemia 1
• Delaying adequate insulin dosing by starting low and titrating gradually is a form of therapeutic inertia that prolongs hyperglycemia and increases complication risk 1

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Adjunctive Therapy Considerations

• Continue or restart metformin at maximum tolerated dose (up to 2,000–2,550 mg/day) unless contraindicated, as this combination reduces total insulin requirements by 20–30% 1
• If the patient was on other oral agents (e.g., sulfonylureas), discontinue sulfonylureas when resuming basal insulin to prevent additive hypoglycemia risk 1

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Expected Outcome

• With immediate resumption of 22 units, fasting glucose should fall to 80–130 mg/dL within 3–7 days 1
• If fasting glucose does not improve within 1 week, the dose was likely insufficient even before the 3-month gap, and further titration upward is warranted 1