Tips for prescribing insulin therapy and diabetes supplies

There are many different insulin preparations and supplies available in order to create individualized regimens for patients.  Here are some tips and a checklist to help avoid getting future calls from pharmacies.

Insulin availability:

·         Standard concentration is 100 units/mL (there’s also a 500 units/mL but rarely used)

o   Expiration

§  Before a pen or vial is opened, it won’t expire until the labeled expiration (could be a year)

§  After a pen or vial is opened, it expires in 28 days

·         Insulin vials

o   Dispensed as a 10mL vial (1000 units/vial)

·         Box of pens

o   Dispensed as 5 pens (3mL or 300 units each so 1500 units per box).  The pharmacy won’t split a box so you can’t prescribe <5 pens.  If you do, the pharmacist will round up to one box anyway.

Insulin syringe prescribing:

• The appropriate needle size is that which minimizes discomfort for the patient but ensures that the insulin will penetrate the skin and deposit in the subcutaneous fat. 
• When prescribing syringes, make sure to write “Insulin syringes” as there are many syringes available of varying sizes.
• The chart below shows the available sizes of insulin syringes:

Insulin syringes availability:

• Available in multiples of 10

Capacity	For doses up to:	Gauge	Needle length
3/10 mL	30 units	28	1/2"
		29	1/2"
		31	5/16”
1/2 mL	50 units	28	1/2"
		29	1/2"
		31	5/16”
1 mL	100 units	27	5/8”
		28	1/2"
		29	1/2"
		31	5/16”

Example: You want to prescribe 14 units three times a day.  Select 3/10 mL because it holds up to 30 units.  If you select a larger than necessary size, accuracy decreases and it becomes harder to read the markings on the barrel. Select the 31 gauge as this is generally more comfortable than thicker gauges.

*Note:  If someone’s insulin is around 30 units and they’ll be adjusting their dose in the future, give them the 1/2 mL (50 units maximum) since they won’t be able to use the 3/10 mL once they get to 31 units per injection.

Pen needle prescribing:

• All you have to write is “Pen needles” and one size of the left column from the chart below.  You don’t need to write “Nano 5/32” 32 gauge” because if you make a mistake (writing something that doesn’t exist like “Mini 32 gauge”) the pharmacy will have to call you.
• For pen needles, patients with little fat should be given the ‘Nano’ or ‘Mini’ whereas patients with more fat should get the ‘Short’ size.  The ‘Original’ is generally not used and may not even be stocked at the pharmacy.
• The chart below shows the available sizes of pen needles: 

Insulin pen needles availability

• Only available in boxes of 100

	Needle Length	Gauge
Nano	4 mm (5/32”)	32
Mini	5 mm (3/16”)	31
Short	8 mm (5/16”)	31
Original	12.7 mm (1/2”)	29

Glucometer prescribing:

• If you don’t have a preference, you can write “Glucometer – Use as directed – Dispense #1”
• If you do prescribe a specific brand and it’s different from what the insurance covers, the pharmacist will call you
• If the insurance company has a preference, the pharmacist will pick that one
• If the insurance company doesn’t have a preference, the pharmacist and patient can then pick any glucometer

Glucose test strip prescribing:

• Available in boxes of 25, 50, and 100
• You should calculate how many days supply you want the patient to receive and then prescribe the corresponding number of strips rounded to an available size.  Writing “Dispense 1 box” will cause the pharmacist to dispense the smallest size (25 strips) so your patient could run out before their follow up appointment.
• You don’t need to write the brand of test strips, the pharmacist will match the strips to whatever glucometer the patient is getting or has at home.  If you know what brand the patient is using, write it on the prescription – sometimes the patient doesn’t personally fill their medications at the pharmacy and their family member may not know what device they have.

Lancet prescribing:

• Only available in boxes of 100
• You don’t need to write the brand of lancets, the pharmacist will match the lancets to whatever glucometer the patient is getting or has at home.  Again, if you know the glucometer brand, write it on the prescription.
• The brands need to match because lancets are used with the lancing device which comes with the glucometer.

Common Prescribing Errors:

·         Don’t write “Use as directed” on any diabetes supply prescriptions (except glucometer)

o   Write out the whole directions on each of the prescriptions.  Sometimes people go to different pharmacies so if the frequency, for example, is only on the insulin pens and not the pen needles, lancets, or strips, the pharmacist may call you to clarify.

·         Don’t mismatch your long and short acting formulations

o   Eg. Lantus 15 units TID is incorrect

·         Don’t give the wrong administration supplies with your choice of insulin

o   Give syringes with insulin vials and give pen needles with pens

o   If you give someone an insulin pen and a syringe, they’re not going to be able to use the insulin

·         Don’t give someone pens for basal and vials for bolus insulin or vice versa

o   This forces them to buy excess supplies and unnecessarily makes the regimen more complex

·         Don’t forget to write the diagnosis code

o   Some insurance companies will require this to adjudicate the claim

·         Don’t forget to make sure that every patient on insulin has the following supplies on the checklist below:

Prescribing Checklist (Recommended by ADA Guidelines):          1.  Insulin (vial or pen)          2.  Corresponding syringes or needles          3.  Glucometer          4.  Test strips          5.  Lancets          6.  Alcohol Swabs (Medicaid and some insurance covers these)          7.  Glucagon emergency kit & medical alert charm

References:

1.  BD Website.  Available at: http://www.bd.com/hypodermic/products/BDInsulinSyringewithPermanentNeedle.asp

photo by heather aitken