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  • Dr Simon Moore MD CCFP

DIABETES DRIVING DON’TS and the 2-4-6 Rule

NEW CHAPTER in the 2018 Canadian Diabetes Association guidelines: Diabetes and Driving


A 62-year-old female with Type 2 diabetes presents to your clinic. She has had hypoglycemia in the past but did not feel any symptoms of low blood glucose.

  1. What strategies can reduce her risk of hypoglycemia? List SIX.

  2. She reports she is leaving on a lengthy road trip to Las Vegas tomorrow. What recommendations do you make for self-monitoring of blood glucose if she is driving?

Answers are in the blog post below.


"Can I keep my job as a truck driver now that I have diabetes?"

If your patient on an exam or in clinic asks you about driving with diabetes, think about The Review Course 2-4-6 Rule for driving & diabetes.

This rule was created by The Review Course, and is consistent with Canadian Diabetes Association 2018 recommendations. See our blog post on what's new in the 2018 Canadian Diabetes Association recommendations.

Here's the 2-4-6 Rule for Driving & Diabetes:

2 - For long road trips, consider checking your sugar every TWO hours (or real-time monitoring) IF you have hypoglycemia unawareness...

4 - For most patients with diabetes (i.e. without hypoglycemia unawareness) check your sugar every FOUR hours on a long road trip. If you develop a low sugar reading, DON'T start driving for at least FOURty minutes and your sugar has returned to normal.

6 - Keep an emergency supply of sugar (dextrose tablets, juice box) in the car. SIX lifesavers does the trick as that contains the recommended 15 mg dose of dextrose.


DON'T start driving if your glucose is low (< 4 mmol/L). Pull over if you get a low while driving.

DON'T start driving until at least 40 minutes after you have treated a low sugar episode AND your sugar has returned to > 5 mmol/L.

DON'T allow a patient to continue driving if they have any episode of severe hypoglycemia while driving in the past 12 months.

DON'T allow a patient to continue driving if they have more than 1 episode of severe hypoglycemia while awake but not driving in the past 6 months for private drivers, and in the past 12 months for commercial drivers.

DON'T allow the past two situations to go unreported. . . inform the local driver licencing body.

Finally, for an exam, be able to counsel on how any condition can affect driving. (If you attended The Review Course, remember you learned The Review Course 4-6-8 Rule for counseling patients who are using marijuana, based on the CFPC's position statement on marijuana - see page 190 of your 2018 The Review Course manual if you need a reminder).


Answer to question #1:

a. Ask about hypoglycemia at every clinic visit

2b. Avoid medications associated with recurrent or severe hypoglycemia. High risk: insulin, secretagogues (meglitinides, sulfonylureas)

Low risk: Metformin, SGLT2 inhibitors, DPP-4 inhibitors, GLP-1 agonists

c. Standardized hypoglycemia education program

d. Structured diabetes education and folow-up

e. Increased frequency of self-monitoring of blood glucose (SMBG)*

f. Less stringent glycemic targets

g. Psycho-behavioural intervention program (to help her become aware of her blood glucose symptoms)


Islet cell transplantation, pancreas transplantation, insulin pump, continuous glucose monitoring, or sensor-augmented pump - these ARE recommended for severe recurrent hypoglycemia, or hypoglycemia unawareness, but only in patients with Type 1 diabetes (the patient in this question has Type 2 diabetes).

*This should only be done for patients at highest risk - see the Choosing Wisely recommendation to avoid using SMBG if not using insulin.

Answer to question #2:

For long road trips, consider checking blood glucose every TWO hours (or real-time monitoring) if you have hypoglycemia unawareness.

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