Insulin on the NCLEX: Everything You Need
Insulin types by onset/peak/duration, sliding scale, hypoglycemia management, NCLEX traps.
Insulin is high-alert. The NCLEX tests onset/peak/duration by type, mixing rules, sliding scale, and hypoglycemia.
Rapid-acting
Lispro (Humalog), aspart (NovoLog), glulisine. Onset 5-15 min, peak 1-2h, duration 3-5h. Give with meal.
Short-acting (regular)
Regular (Humulin R, Novolin R). Onset 30 min, peak 2-4h, duration 5-8h. Give 30 min before meal. Only insulin given IV.
Intermediate-acting
NPH (Humulin N, Novolin N). Onset 1-2h, peak 4-12h, duration 12-18h. Cloudy, roll, don't shake.
Long-acting
Glargine (Lantus), detemir (Levemir), degludec (Tresiba). Onset 1-2h, no significant peak, duration 20-24h. Don't mix with other insulins.
Mixing
When mixing regular + NPH: clear before cloudy (regular first into syringe). Long-acting (glargine, detemir) never mixed.
Hypoglycemia
Signs: shaky, diaphoretic, confused, tachy. Tx: 15 g fast carb (4 oz juice, 3 glucose tabs). Recheck in 15 min. If unconscious: D50 IV or glucagon IM.
Frequently asked
Peak time for regular insulin?
2-4 hours after administration. This is when hypoglycemia is most likely.
Sliding scale only?
Generally inadequate as sole therapy in T1DM. Used as adjunct in T2DM or in inpatient setting.
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