Information Regarding Insulin Storage and Switching Between Products in an Emergency
Insulin from various manufacturers is often made available to patients in an emergency and may be different from a patient's usual insulin. After a disaster, patients in the affected area may not have access to refrigeration. According to the product labels from all three U.S. insulin manufacturers, it is recommended that insulin be stored in a refrigerator at approximately 36°F to 46°F. Unopened and stored in this manner, these products maintain potency until the expiration date on the package.
Insulin products contained in vials or cartridges supplied by the manufacturers (opened or unopened) may be left unrefrigerated at a temperature between 59°F and 86°F for up to 28 days and continue to work. However, an insulin product that has been altered for the purpose of dilution or by removal from the manufacturer’s original vial should be discarded within two weeks.
Note: Insulin loses some effectiveness when exposed to extreme temperatures. The longer the exposure to extreme temperatures, the less effective the insulin becomes. This can result in loss of blood glucose control over time. Under emergency conditions, you might still need to use insulin that has been stored above 86°F.
You should try to keep insulin as cool as possible. If you are using ice, avoid freezing the insulin. Do not use insulin that has been frozen. Keep insulin away from direct heat and out of direct sunlight.
When properly stored insulin becomes available again, the insulin vials that have been exposed to these extreme conditions should be discarded and replaced as soon as possible. If patients or healthcare providers have specific questions about the suitability of their insulin, they may call the respective manufacturer at the following numbers:
Lilly: 1-800-545-5979
Sanofi-Aventis: 1-800-633-1610
Novo Nordisk: 1-800-727-6500
Additional Storage Information for Insulin Pumps
Insulin contained in the infusion set of a pump device (e.g., reservoir, tubing, catheters) should be discarded after 48 hours. Insulin contained in the infusion set of a pump device and exposed to temperature exceeding 98.6°F should be discarded.
Insulin Switching
Switching insulin should always be done in consultation with a physician and requires close medical supervision, and if possible, close monitoring of blood glucose. If medical supervision is not possible under emergency conditions, the following recommendations may be considered. Make sure to closely monitor your blood glucose and seek medical attention as soon as possible.
Short-acting (regular insulin) and Rapid-acting Insulins
One brand of regular insulin (e.g., Humulin R, Novolin R) may be substituted for another brand of regular insulin and for rapid-acting insulins (e.g., Humalog, NovoLog, Apidra), and vice versa, on a unit-per-unit basis in emergency conditions.
Regular insulins are to be injected approximately 30 minutes before the start of each meal. Rapid-acting insulins begin working more rapidly than regular insulin and are to be injected no more than 15 minutes before the start of each meal to avoid dangerously low blood glucose levels.
Intermediate and Long-acting Insulins
One intermediate-acting insulin product (e.g., Humulin N, Novolin N) may be substituted for another intermediate-acting insulin product on a unit-per-unit basis in emergency conditions. Likewise, these intermediate insulins may also be substituted for long-acting insulins (e.g., Lantus, Levemir) on a total unit-per-day basis, or vice versa in emergency conditions.
- Importantly,when switching from a once a day long-acting insulin (e.g., Lantus, Levemir) to an intermediate-acting insulin the dose of the once a day long-acting insulin should be cut in half and given as two injections of intermediate acting insulin, one in the morning with breakfast and one in the evening with dinner to avoid dangerously low blood glucose levels.
- When switching from an intermediate-acting to a once a day long-acting insulin, add up the total amount of intermediate-acting insulin units for one day, and give it as a single long-acting insulin dose once a day.
Close monitoring of blood glucose and adjustment in insulin dose may be needed in the transition period.
Insulin Mixes
Switching between types of insulin should be done in consultation with a physician and requires medical supervision, and if possible, close monitoring of blood glucose.
What is an Insulin Mix
Insulin mixes contain a ratio of intermediate- and short/rapid-acting insulin. The first number denotes the quantity of intermediate insulin and the second number denotes the quantity of short/rapid-acting insulin delivered with each dose administered. For example, each dose of a 70/30 mix contains 70% intermediate-acting insulin and 30% short/rapid-acting insulin.
Switching from Your Insulin Mix: Substitution or Replacement
Patients using pre-mixed insulin products (e.g., Humulin 70/30, Humalog Mix 75/25, Novolin 70/30, NovoLog Mix 70/30) have the following options to consider:
- In emergency conditions, one insulin mix product may be substituted for another on a unit-per-unit basis.
- Insulin mixes containing a rapid-acting insulin analog (e.g., Humalog Mix, Novolog Mix) should be injected closer (within 15 minutes) to the start of the meal compared to mixes containing regular insulin (e.g., Humulin 70/30).
- First, substitute an intermediate-acting component of the mix (e.g., for most of the examples listed above this will be approximately 70% of the total units for each dose) with an intermediate-acting or a long-acting insulin on a unit-per-unit basis.
