Insulin injections are often included in the daily functioning of people with type 2 diabetes. They work really well but have to be taken once or twice a day. If you lead a busy life, you might just forget to take a dose at the regular time. Alternatively, you might even forget to restock cartridges for your insulin pen. About 1/3rd of people with diabetes skip at least 1 dose of insulin per month. (1) Some of them genuinely forget it, while others deliberately skip a dose. However, in both scenarios, it is a bad idea to miss your insulin doses. So, what should you do if you skip a dose?
Know your insulin type
The consequences of skipping a dose and the action you should take vary a lot. One of the factors is the type of insulin that you have been prescribed. Most common is a dose of mixed or long-acting insulin that needs to be taken once daily. However, you might also be taking one of the following:
- A rapid- or short-acting insulin-like regular, lispro, aspart, etc.,
- Pre-Mixed insulin, or
- Ultra-Long acting insulin, e.g., insulin degludec (Tresiba).
What can happen if you miss a dose
With any of the aforementioned insulin types, but more commonly the comparatively shorter-acting ones, missing an insulin dose can lead to a rise in blood sugar and/or ketone levels. These are known as hyperglycemia and ketoacidosis, respectively. If you missed a dose, check if you have any of the following symptoms:
- Increased thirst
- Frequent urination
- Confusion or drowsiness (feeling sleepy, tired, or lethargic; ‘brain fog’)
- Fruity smell in your breath
- Feeling nauseous or vomiting sensation
- Loss of appetite
- Dry and/or flushed (reddened) skin
- Increase in heart rate
In addition, you should also check the glucose and ketone values in your blood or urine using your glucometer and dipsticks.
What should you do
1. Be sure
You have to be very sure that you missed a dose. This is because taking an extra dose can lower your blood sugar levels dangerously.
Rapid- or short-acting insulin insulin
These insulin types (e.g., lispro) are generally taken 30-60 minutes before or after a meal. If you remember that you have skipped it just a little later, take a dose. If some time has passed (more than an hour), you need to check your glucose levels and/or follow the instructions provided by your doctor or you should call your doctor. (2)
Intermediate-acting or mixed insulin
Isolated intermediate-acting insulin is rare and is often combined with rapid- or short-acting insulin. Therefore, it depends on which insulins are used and in what combination (30-70 or 50-50). The following is a general rule, but be sure to check with your doctor beforehand for such insulins. (3)
Within 1.5-2 hours: If you remember to take your dose within 1.5-2 hours, you can just take your regular dose normally.
After 1.5-2 hours: Remembering the missed dose too late affects the next dose as well; if you take insulin much later than usual, then your insulin levels will be higher than usual during your next dose. This can increase the risk of hypoglycemia. Typically, you should monitor your symptoms as well as your glucose and ketone levels (blood and/or urine, as you normally do). If the levels are high, then call your doctor or follow the instructions provided, if any. Wait till the time of the next dose and take that dose normally.
Long- and ultra-long-acting insulin
Here, you have a comparatively wider window. This insulin is generally taken in the morning, and if you miss it, you can take it during your waking hours. (4,5) Ensure that your next dose is at least 8–10 hours away. If it is close to or less than that, skip the dose and take the next one as usual.
At any point
If you have any of the symptoms we mentioned earlier or if your glucose or ketone values are high (even in the absence of any symptom), call your doctor.
If your doctor has already given you something for this (e.g., rapid-acting insulin), remember to take it.
2. Avoid skipping
While missing one dose may give you stress, missing doses more frequently can lower your glucose control in the long run. (1) This opens wider doors to various complications of diabetes. Avoid skipping the dose in the first place, and ensure that you take your insulin on time every day.
- Josse RG, Woo V. Flexibly timed once‐daily dosing with degludec: a new ultra‐long‐acting basal insulin. Diabetes, Obesity and Metabolism. 2013;15(12):1077-84.
- Insulin Lispro (Humalog®): Important Patient Information [Internet]. University of Rochester Medical Center. 2019 [cited 26 April 2019]. Available from: https://www.urmc.rochester.edu/medialibraries/urmcmedia/medicine/general-medicine/patientcare/documents/humalog_brochure_urmc.pdf
- Insulin Aspart Protamine and Insulin Aspart (Novolog Mix 70/30®): Important Patient Information [Internet]. University of Rochester Medical Center. 2019 [cited 26 April 2019]. Available from: https://www.urmc.rochester.edu/medialibraries/urmcmedia/medicine/general-medicine/patientcare/documents/novologmix_brochure_urmc.pdf
- Insulin Detemir (Levemir®): Important Patient Information [Internet]. University of Rochester Medical Center. 2019 [cited 26 April 2019]. Available from: https://www.urmc.rochester.edu/medialibraries/urmcmedia/medicine/general-medicine/patientcare/documents/levemir_brochure_urmc.pdf
- What To Do If Your Patient Missed An Insulin Dose [Internet]. Tresibapro.com. 2019 [cited 26 April 2019]. Available from: https://www.tresibapro.com/peer-perspectives/hear-from-your-peers/missed-insulin-dose.html