Insulin Needles, Syringes, Pens and Injections

How can optimizing insulin injection technique and its effect on blood glucose control?

Mean reductions of:

• A1C → 0.58%

• FBS

• decreased TDD

Why is the approach to teaching insulin injections so critical?

• the more you can listen to a patient the better the odds the patient will carry through

• may only be the HCP who takes time to adjust daily insulin

• may need to help them more than once

• should be routinely checking on injection technique

What are some common concerns about initiation of insulin?

• fear of injections and needle phobia

• fear of pain

• anxiety to perform injection prep

• fear of giving wrong dose

• feeling like need of insulin is a personal failure

• anticipation of weight gain on insulin

• fear of increased risk of hypoglycemia

• misconceptions

• stigma

How often does a patient need to be testing blood sugars before initiating insulin?

A minimum of one more to know they are committed and will continue to do so when start insulin.

What is the true needle phobia called?

Trypanophobia - extreme fear of needles/pointed objects, or fear of any type of injection.

What kind of response dose a patient have, if they have trypanophobia?

Result in a vasovagal response → increase in heart rate and BP, then followed by a rapid drop (can lead to fainting).

What are some other types of phobias?

• associative phobia

  • e.x. worried because grandmother lost leg after starting insulin

• resistant phobia

  • e.x. history of being held down or forced to get injections

• hyperalgesia

  • extreme pain with injection

• vicarious phobia

  • just the site of needle causes anxiety

What is the gauge of a needle?

Diameter or thickness of the needle.

What does it mean f the gauge of the needle in larger?

The larger the gauge the thinner the needle.

Comes from passing a wire through a drawing die - the more times it is passed you shave a bit off the smaller you get. The number comes from the number of times it is passed through.

When would you want to use a smaller gauge needle?

Use a smaller gauge needle for larger insulin doses, this allows for a larger volume to flow through the needle with faster and greater ease.

What size needle can be used in most body types; children, slim adults and obese patients?

4-5 mm; the thickness of skin doesn’t change (approx. 2mm thick at the 4 most common injection sites)

When might you want a longer needle?

When you are injecting large volumes of insulin.

What can happen if a needle is re-used?

• needle can become bent, blunted, broken or blocked

• this can compromise insulin delivery, irritation, pain and increase risk of lipohypertrophy

What can happen if a needle is left attached to a pen?

You may get leaking of insulin at the needle, and allow air into the cartridge which may affect the concentration of insulin. Is also more prone to contamination or infection.

What is the benefit of the silicone lubricant on a needle?

• allows for smoother insertion

• one-time use only

  • will not be available for subsequent injections

If for financial reasons a patient needs to reuse a needle, what can you recommend to a patient?

Can recommend to use no more than 3x with the same needle.

What is an auto-shield needle?

• helps hide the needle

  • helpful for patients who are elderly, pediatric, dexterity issues or are anxious at the sight of needles

• only for 5mm

• Auto-cover for 8mm

What is thin-walled technology in needles?

• increases interior diameter

  • allows for 31% higher insulin flow

• less thumb force required

• less painful injections

• easier to insert

What is a bevel in regards to needles?

• angled edges at the needle tip

• creates the sharp point and facilitates injection into skin

What is the purpose of increasing the number or bevels?

• easier to enter the skin

• increase comfort/reduce pain

What is common number of bevels in insulin needle?

• standard = 3 bevels

• BD pen needles = 5 bevels

  • preferred by patients and less penetration force in clinical trial

What is a flat injection base needle?

• allows for more comfortable injection

• don’t get pushing of the top “hub” into injection site

• can minimize bruising

What are the needles made of (worried for allergies)?

• Nickel

• Silicone

What does an allergy for nickel look like?

• redness, irritation, rash that spreads a bit

• can confirm with allergy/patch test for Ni or stainless-steel

What about insulin allergies?

• Very rare

• most likely allergy to a preservative

  • cresol or metacresol (not present in GLP-1)

What size insulin syringes are there?

• come in the size 30,50 and 100 units

  • related to barrel size

How do you choose a syringe?

Based of the number of units you use per injection (e.x. if dose is 45U choose a U-50 unit size syringe). Usually have ½ and whole unit marking to help with dose accuracy, especially pediatric dosing.

What are the two types of insulin pens?

• disposable, pre-filled pens

• refillable, cartridge-filled, durable pens

What is a prefilled insulin pen?

• cartridge already loaded

• can dose in 1 unit insulin amount

• less steps = easier for elderly, cognitively or physically impaired patients

  • “clicking” to help vision-impaired patients

What is the difference/special about Novo Nordisk FlexTouch?

• different tactile design on push button

  • less force required

  • easier to push the button for patients with arthritis

What are some characteristics of refillable, cartridge-filled, durable pens?

• can last several years - but does have a shelf-life

• available in 0.5-1units

• more issues with piston, or pen can stop working or get blocked

• if use 2 different insulin, choose different coloured pens

• have “clicking” sound to help vision impaired

What is special about the Eli Lilly HumaPen Memoir?

Records the date, time and amount of last 16 doses (including priming doses)

What is special about the Novo Nordisk Echo?

Half-unit dosing and memory function recording last insulin dose and how much time passed since last injection.

Device options for basal insulin

• Levemir and Tresiba

  • FlexTouch

  • Novo Pen 4 or Echo

• Lantus

  • SoloStar

  • ClikStar

• Toujeo

  • SoloStar

Device options for rapid insulin

• NovoRapid

  • FlexTouch

  • NovoPen 4 or Echo

• Apidra

  • SoloStar

  • ClikStar

• Humalog

  • KiwkPen

  • HumaPen Luxura, Memoir or Savvio

Daily GLP-1 agonist injectable pens

• Victoza (liraglutide)

Weekly GLP-1 agonist injectable pens

• Trulicity (dulaglutide) - single dose

• Mounjaro (tirzepatide) - single dose

• Ozempic (semaglutide) - multi-dose

Combo pens

• Xultophy

  • degludec +liraglutide in FlexTouch

• Soliqua

  • glargine + lixisenatide in Solestar

Injectable compounds for obesity

• Saxenda

• Wegovy

What type of system does a pen use to deliver the insulin?

Hydraulic delivery system

• uses a plunger pushing on a column of fluid to deliver the insulin

• when depress the plunger of a pen to its base, the delivery has only just begun

Why is it important to keep the pen in place for at least 6-10 seconds?

Injection process with pen is slower than expected. If don’t hold long enough are going to under-dose.

What is the difference between priming an insulin pen and a GLP-1 agonist pen?

• insulin

  • need to prime prior to each insulin dose

• GLP-1 agonist

  • need to prime with first dose

What do you need to know about doses of 50 units and above?

• for injections 50+ divide into 2 injections

  • improves absorption of insulin

  • better blood glucose control

  • easier use of pen

  • less irritation

  • less force required to depress plunger

• can use the same needle

• doses >50U may delay absorption of fast, rapid insulins

What are the main injection sites abdomen, outer thigh and top of buttocks?

• Have a layer of fat below the skin, that helps absorb the insulin

• Do not have many nerves, so minimal discomfort

What do we need to be concerned about with the outer thigh and exercise?

If warmer/increased blood flow, can take up too quickly

Why is the abdomen the preferred site?

• lots of “real estate”

• easy to reach

• insulin absorbed quickly, consistently/predictably

• easy to give at table under a shirt

Why do you avoid near the belly button?

Tissue is tougher, so insulin absorption will not be as consistent.

What can you tell a patient about bruising?

Local bruising and/or bleeding may occur at injection site; is more common in patients taking antiplatelet therapy. Do not appear to be associated with needle length or injection site, but sue to injection technique.

Where are the injection site in pregnancy?

• abdomen is preferred

• shorter needles needed (4 or 5mm)

• during 3rd trimester, when taught skin use the lateral sides

When do lipo’s happen?

Repeated tissue trauma, localized to same area, in the presence of insulin (growth hormone).

What happens if insulin is injected into a lipo?

Decreased absorption, can be reduced by ~40%

How does glucagon injection work?

Comes with syringe containing the dilutant and the bottle of un-reconstituted glucagon powder (contents of the syringe are inactive). Mix the contents of the syringe with the glucagon in the bottle before giving.

How does intranasal glucagon work?

Dry powder nasal spray, each spray contains 1 dose. Given in one side of the nose, and is absorbed without inhaling.

What is the difference of intranasal and IM glucagon?

Intranasal takes about 4 minutes longer to raise blood glucose than IM, but IM takes time to reconstitute and can lead to admin errors.