Which insulin preparation offers a flat peakless profile due to the formation of micro-precipitates at the injection site, providing basal insulin coverage for >24 hours?
- A Insulin glargine (acidic solution that precipitates at physiological pH in subcutaneous tissue)
- B Insulin detemir (bound to albumin via fatty acid chain, prolonging action)
- C All three have identical prolonged peakless profiles by the same mechanism
- D Insulin degludec (forms multi-hexamer depot at injection site with slow dissociation) ✓
Explanation
Insulin degludec forms large soluble multi-hexamer chains upon subcutaneous injection. These slowly dissociate into di-hexamers and then monomers for absorption — creating a depot effect lasting >42 hours with an extremely flat (essentially peakless) profile and lowest within-day variability (coefficient of variation ~20% vs 43% for glargine). Insulin glargine precipitates at physiological pH (from acidic solution) creating a microcrystalline depot lasting ~24 hours. Insulin detemir binds albumin via a fatty acid chain, extending action to 18–24 hours. Each has a distinct prolongation mechanism.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.