Insulin therapy for Type 1 and 2 DM Flashcards
How much insulin is secreted in pancreas/day?
30 units from the beta cells
What closes the ATP-sensitive K+ channel?
Increased ATP/ADP ratio
When did recombinant human insulin become available for general use? When were analogs introduced?
1982 and 1996
Who needs insulin therapy?
- Anyone with Type 1 DM
2. Some patients with Type 2 DM - those who can’t achieve glucose control
How many units of insulin within each 10mL vial?
1000 units; with pens don’t need to store in fridge
How are the A and B chains connected? and where do the insulin analogs act?
A and B are attached by disulfide bonds.
- Lispro - proline and lysine reversed
- Lysine at B3 and glutamate at B29 substituted
- Aspartae substitued instead of Proline
Activity of rapid-acting insulins
- onset 5-15 mins
- peak 1-1.5 hrs
- duration 3-5 hrs
can do as injection or insulin pump that you can bolus right before meals; dissociates into monomers after injection
Inhaled insulin
Afrezza - came out last year
- very very quick 5 min onset
- done by 2 hrs
- set-dose cartridges for inhalation device (risk of under or over dosing because just available in 4 unit increments)
- administered just prior to meal
Short-actin insulin
Regular human insulin
- Onset: 30-60 min
- peak: 2 hr
- duration: 6-8 hr
- inject 30 mins before food
- knowing when to inject was hard because who knows when food is early
- risk for stacking and hypoclycemia
Intermediate-acting
NPH
- onset 1-3 hrs
- peak 6-8 hr
- duration 12-16 hr
- injection only (BID for basal coverage - issue for ppl who play sports etc. because it won’t be enough)
- CLOUDY solution
Long-actin
About 24 hrs
- onset 1-1.5 hrs
- no pronounced peak
- duration is 24 hrs (glargine) or 12-20 hrs (detemir)
- SQ injection only
- CANNOT be mixed in same syringe with any other insulins… this is frustrating for people
Premixed insuins
Biphasic, usually 70/30 of NPH/regular
- Used twice a day before AM and PM meals
- Not a lot of control, you better have a set schedule
- SQ injection only
- Mixture of intermediate and short or rapid acting (rapid start working faster)
Caveats to insulin pharmacokinetics
- Volume
- Concentration (U500 - 5x more concentrated)
- Body site of injection - how much body fat
- How much fat… presence of lipodystrophy (scarring at injection site)
- Intradermal vs. subcutaneous vs. intramuscular
Explain bolus therapy
- Use long-acting
2. Bolus with rapid or short so that you can adjust for carb content in meals
Correction-dose insulin
- Insulin taken to correct pre-meal hyperglycemia
- often added to meal/prandial dose
- can be taken between meals alone
- CAUTION: do not stack corrections
Pros and cons of insulin pump therapy
Pros:
- eliminates multiple injections
- different basal rate settings (great for week vs. weekend)
- Small increment boluses possible
- Different bolus types (square vs. dual wave)
Cons:
- Upfront cost
- Significant training
- Motivation
- Ability to troubleshoot
- Interruption of infusion or “bad site” can lead to DKA within hours
What affects patient regimen?
- Age
- Duration of diabetes
- Complications? Retinopathy?
- Motivation
- Self-management skills
- Daily schedule - skipped meals? activity?
Insulin with T2DM
ALWAYS IF:
- Insulin deficiency on presentation (weight loss, fasting >250, random >300, A1c >10)
- Hospital admission for diabetic emergency
How to start insulin in T2DM
Most flexibility = most complicated, most injections
Regimented = least injections, better have a good set schedule
- Start with NPH glarginine/detemir 10 units and check A1c in 3 months…
- If not at target, add more dosage or rapid-acting injections
- If too low, reduce dose
Odd inpatient hyperglycemia risks
- Glucocorticoid meds
- Enteral or parenteral nutrition therapy
- Renal disease
- CF related diabetes
