Insulin. The word is like an eye, nose, or ear to me, but how much do I know about taking care of my liquid lifeline? Those precious vials and pens that keep us happy and healthy? This question occurred to me when I visiting with family and my brother in law took out the bottle insulin they use for their dog and slowly turned the bottle from end to end. I commented he should roll it, because insulin doesn't like to be shaken. I asked how long he used his bottle of novolog and he said, "until it runs out". As we talked about the do and don'ts, it was a quick trip to grab my ipad and check my facts! For example, I always stored my insulin in the compartments on the refrigerator door. Found out that's a no-no! So what else do we need to know about insulin care?
A couple of key things to know about insulin, U-100 means 100 units in every cc of fluid. The alternative is diluted insulin, where you might see as low as U-10, or super concentrated insulin, which could read U-400, but the standard for most is U-100.
Next are the types of insulin on the market. Analog insulin are similar to human insulin, but with small changes to control their onset, peak and duration. The current analogs available are humalog, novolog, detemir, lantus and apidra.
Rotating the injection sites is ultra important, especially for a type 1 who will be injecting for the rest of life! Repeated injections in the same area for a prolonged period of time causes the fat below the skin to harden and swell, this called lipodystrophy, or it can wear away the tissue which is called lipoatrophy. The effect of these two conditions causes problems absorbing the insulin, so to avoid this problem rotating the injection site is key!
There is great debate about why insulin cannot be shaken. Many think it has to do with bubbles in the syringe or pen and then air getting into the body. But the truth about not shaking insulin is the protein chain that makes up the insulin! By shaking insulin you could slightly alter the protein chain and decrease it's effectiveness. I confirmed this with Dr. Cogan. Insulin is made up of amino acids chains that are held together by disulfide bonds, when shaken the disulfide bonds break apart altering the insulin formula.
The biggest eye opener for me was learning about storage! Like I said, the fridge door is a no no! Unopened vials and pens should be stored in the fridge, but on a shelf, not the door! This will keep the insulin fresh until the expiration date. Once you have opened the insulin, it no longer needs to be refrigerated, but it should be kept out of direct sunlight and away from direct heat. So don't leave insulin in your car! (ADA tip) If you are hiking or traveling, where insulin will be vulnerable, try a FRIO cooling case.
Once insulin is in use, the pens and vials last less than a month. Tiny contaminants get into the vials and pens causing the insulin to loose it's potency, so if you are seeing spikes in blood sugars at the end of the month, start a new pen or vial! And if you see any insulin discoloration, toss it and start a new bottle.
In some cases, a new vial or pen may not be potent, sometimes this happens from having been shipped in heat, or something that was not packaged correctly. If you have this problem or question it's effectiveness, take it back to the pharmacy and have them replace it!
If you have more insulin tips, please chime in!