• Credits

  • Section Writer: Dr. Om J Lakhani
  • Section Editor: Dr. Om J Lakhani

• Q. What is the structural difference between insulin aspart and regular human insulin?

  • Aspartic acid replaces proline at B28 position in Insulin Aspart

• Q. When is the peak seen in premix insulin?

  • Remember, in premix insulin, when the regular and NPH are combined, both tend to have a single common peak
  • This is less of a problem with insulin analog combined with NPH

• Q. What happens to the peak when the concentration of NPH and Regular insulin are changed?

  • In 50:50 insulin – the peak occurs earlier and higher insulin concentration in the first 6 hours compared to 70:30 insulin

• Q. Can insulin glargine and detemir be combined with other insulins?

  • No
  • This is because they have an acidic pH

• Q. Give the onset, peak, and duration of various insulin?

  • Lispro/Aspart/Glulisine
    - Onset- 5-15 min
    - Peak- 45-75 min
    - Duration - 2-4 hours

    Regular human insulin
    - Onset-30 min
    - Peak- 2-4 hours
    - Duration - 5-8 hours

    NPH
    - Onset- 2 hours
    - Peak- 4-12 hours
    - Duration - 18-28 hours

    Glargine U100
    - Onset- 2 hours
    - Peak- None
    - Duration - 22-24 hours

    Degludec
    - Onset- 2 hours
    - Peak- None
    - Duration -36-40 hours

• Q. Are these timings always the same in all patients?

  • No
  • They are based on small doses given to normal subjects
  • It may vary in the clinical situation

• Q. Is the absorption of insulin consistent?

  • No
  • It may vary by 25-50%  in the same person
  • Variation is most with NPH and least with rapid-acting analogs
  • It is also seen with glargine

• Q. What is the relation between detemir dose and duration?

  • Higher the dose of detemir, longer the duration

• Q. What is the relation between the subcutaneous depot and variability?

  • Larger the subcutaneous depot, the more the variability and lesser the absorption
  • Hence Insulin pumps do very well because they have a tiny depot

• Q. What are jet injectors?

  • They produce a smaller depot and less painful
  • However, they are expensive and difficult to maintain
  • Hence not recommended at present

• Q. What is the most significant advantage of a pen over a syringe and vial?

  • When small doses are used- less than five units, syringe produces more errors than pen

• Q. What is the difference between shallow injections and deep injections?

  • Shallow injections produce intradermal injection – more negligible effect
  • Deep injections produce intramuscular injections – a more rapid effect

• Q. What is the microfine and ultrafine needle?

  • Microfine – 27 G
  • Ultrafine – 29 G

• Q.  What are the sites for injection?

  • Upper arm
  • Upper leg
  • Abdomen
  • Buttocks

• Q. Which site has the fastest and which has the slowest absorption?

  • Abdomen- fastest
  • Slowest –leg and buttocks
  • Arm – intermediate

• Q. What type of insulin is given where?

  • Give premeal bolus insulin at abdomen- faster absorption is more useful
  • Give basal insulin at the buttocks and legs- slower absorption- prolonged duration of action

• Q. How is insulin stored?

  • A strict cold-chain must be maintained when stored and transported from manufacturer to storage facility to Pharmacy

  • Unopened cartridges, Pre-filled pens and vials must be stored at 2-8 °C

  • In-use cartridges, Pre-filled pens and vials must be stored at 15-30°C

  • Typically patients as asked to store it in refrigerators on the side compartment (an not Frozen)

  • Pens are stored WITHOUT the needle-cap on. If stored with the needle-cap air can enter the cartridge causing clogging or the thermo-insulation can leak

  • In areas with inconsistent electricity or no refrigeration, it can be stored in Earthen pots (Matkas) with water.

• Q. What is the shelf-life of insulin?

  • Advised to look at product monograph for exact shelf-life for insulin-in-use.
  • On an Average, it is 28 days.

• Q. Whare care must be taken during the transport of insulin?

  • Exposure to temperatures more than 30 degrees must be avoided
  • Can be kept in handbag, flasks or special pouches for this purpose
  • During air-travel it must be in the hand luggage and not in the check-in luggage

• Q. How much potency is required for the insulin to be adequate?

  • Insulin should retain a potency of at least 95% to be effective

• Q. At an Indian room temperature of 32-37 degrees, how much potency is reduced?

  • According to a study, the potency of insulin reduced by 15% in the Indian climate if insulin is NOT properly stored

• Detailed lecture on Basics of Basal insulin

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