What to do first
1. Check blood glucose before insulin administration.
2. Match insulin type with meal timing, peak, and ordered route.
3. Identify the peak window because that is the highest hypoglycemia risk period.
Can Lantus Be Mixed With Regular Insulin?
Insulin comparison questions test peak timing, hypoglycemia risk, IV regular insulin, cloudy NPH, glargine no-mix rules, and NPO basal insulin traps.
Study aid - not medical advice. Not a clinical decision tool. For NCLEX pharmacology review only.
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Hold If
Follow protocol and notify the provider for severe hypoglycemia, unclear insulin order, mismatch with meal/NPO status, or symptoms of DKA/HHS.
Do not mix glargine with other insulin. Do not give IV insulin unless specifically ordered and protocol-supported.
Labs to Watch
Blood glucose is the main check. Watch potassium when insulin is used in high-risk contexts because insulin shifts K+ intracellularly.
For DKA or severe hyperglycemia, labs may include ketones, anion gap, electrolytes, renal function, and osmolality as ordered.
Mini Quiz: Test Your Recall
Think through the answer before you reveal the rationale.
Question: Which insulin should never be mixed in the same syringe with other insulin?
Answer: insulin glargine (Lantus).
Review Details
NCLEX Review Notes
Timing Table
Regular: short-acting; onset about 30 min; peak about 2-3 hr; commonly remembered as the insulin that can be given IV when ordered.
NPH: intermediate; cloudy; peak often 4-12 hr in NCLEX resources.
Lantus/glargine: long-acting basal; no pronounced peak; do not mix.
NPH: intermediate; cloudy; peak often 4-12 hr in NCLEX resources.
Lantus/glargine: long-acting basal; no pronounced peak; do not mix.
NCLEX Trap
Trap: draw up glargine with regular insulin to reduce injections.
Answer: do not mix glargine. Regular and NPH mixing rules do not apply to glargine.
Answer: do not mix glargine. Regular and NPH mixing rules do not apply to glargine.
Related Pattern
Clear to cloudy: when regular and NPH are mixed under an order, draw clear regular insulin before cloudy NPH.
NPO: mealtime insulin may be held as ordered, while basal insulin is often continued as ordered, especially for type 1 diabetes.
Review when insulin is held while NPO →
NPO: mealtime insulin may be held as ordered, while basal insulin is often continued as ordered, especially for type 1 diabetes.
Review when insulin is held while NPO →
References
Primary labeling: Lantus (insulin glargine) prescribing information; Humulin R prescribing information; Humulin N prescribing information (DailyMed).
Study-only boundary: This NCLEX summary is not an administration instruction. For patient care, use the current product label, the active order, and local protocol.
Study-only boundary: This NCLEX summary is not an administration instruction. For patient care, use the current product label, the active order, and local protocol.