A nurse is preparing to administer both NPH insulin and regular insulin from separate vials using a single syringe. In what order should the nurse draw up the insulins?
- A.Draw up NPH (cloudy) first, then regular (clear)
- B.Draw up regular (clear) first, then NPH (cloudy)
- C.The order does not matter as long as the doses are correct
- D.Draw up whichever insulin is lower in volume first
Show answer & rationale
Correct answer
B. Draw up regular (clear) first, then NPH (cloudy)
Rationale
B is correct: The mnemonic is 'clear before cloudy.' Regular insulin (clear) is drawn first to avoid contaminating the regular insulin vial with NPH (which contains protamine and could alter the action of future regular insulin doses). NPH (cloudy) is drawn second. A is incorrect: Drawing NPH first risks contaminating the regular insulin vial with protamine from NPH. C is incorrect: Order does matter; drawing cloudy before clear risks contamination and altered pharmacokinetics. D is incorrect: Volume is not the determining factor for draw order.
Key concepts