Humalog is a brand name for a type of insulin known as insulin lispro. It is an analog of human insulin; that is, it has similar properties to normal human insulin and a similar, though slightly modified, chemical structure. Humalog is used to treat patients with type 1 diabetes, whose insulin-producing cells are destroyed and thus cannot produce the insulin that helps the body process sugar correctly. Humalog contains several ingredients as part of the solution that is injected under the skin or used in external insulin pumps.
Insulin Lispro
Insulin lispro is the active ingredient of Humalog. Specifically, when a person with type 1 diabetes injects Humalog, her blood sugar will decrease. This means that the cells within her body are able to make use of the sugar instead of the sugar remaining in the bloodstream and causing symptoms of diabetes. The product information for Humalog indicates that one unit of Humalog insulin is as effective as one unit of regular, human insulin at decreasing the level of blood sugar. However, it acts more rapidly, and has a shorter duration of action, than normal insulin would, so the recommendation is that a person with type 1 diabetes injects herself 15 minutes before eating a meal. This reduces the risk for a dangerous rise in blood sugar levels after a meal.
Hydrochloric Acid 10 Percent
Hydrochloric acid, at a concentration of 10 percent, may be added with or without sodium hydroxide of the same concentration. These compounds are added to ensure that the pH, or acid-base balance, of the insulin solution is correct; it generally has a pH of 7.0 to 7.8; in comparison, the pH of blood is 7.4.
Other Ingredients in a Humalog Injection
Glycerin, sodium phosphate, zinc oxide, and phenol are also part of an injection of Humalog, though these are not considered active ingredients. Water is another important component. Though water would not be considered an "active" ingredient, it is a critical component of the insulin injection because this is what allows the insulin to be injected, and thus be absorbed and used by the person with type 1 diabetes.
References
- Eli Lilly and Company: Humalog 2004
- "UpToDate"; Insulin Therapy in Type 1 Diabetes"; David McCullogh; May 2010
