DISCUSSION
Patients have many obstacles to managing their diseases. This is especially prevalent in patients with diabetes. These patients both experience the emotional stress of being diagnosed with diabetes and are given a wealth of information on diabetes, nutrition, therapy, and insulin-dosing technique at the same time. The information can be overwhelming for patients to hear and for the educator to present. Sometimes health care professionals (HCPs) overlook a patient’s hindrances due to the amount of information they have to give to the patient. For example, in this case, the patient was mixing insulin inappropriately, and it was overlooked by the HCP.
Insulin therapy has been used for several decades. It is obtained from either a pork pancreas or is chemically manufactured to be identical to human insulin. This can be achieved by recombinant DNA technology or chemical modification of pork insulin.4 Insulin is available as short-, intermediate-, or long-acting duration. The pharmacokinetics of available insulins is listed in Table 2.6
Some insulin can be mixed in the same syringe, but these mainly consist of the short- and intermediate-acting insulin. Insulin glargine, a long-acting formulation, should not be mixed with any other insulin due to its pharmacokinetic properties.7 Insulin glargine has been designed to have a low solubility at a neutral pH. After injection, the pH rises and leads to the formation of microprecipitates, causing a slow release of the insulin over 24 hours with no peak. If insulin glargine is mixed, it is likely the pH would be altered before entering the body. In addition, mixing insulin in the same syringe could likely contaminate the dose.
The maker of insulin glargine advises against mixing it with any other insulin.7 Several different studies have been done with admixtures of insulin glargine with short- or rapid-acting insulin. The studies revealed no differences in glycemic control, blunted and delayed rapid-acting insulin peak, the need for larger doses, or worsened glycemic control.8-12
Other education points about insulin administration that are often overlooked or sometimes ignored by patients and that require follow-up for compliance include the following:
• Manufacturers recommend discarding an open bottle of insulin at room temperature after 28 days.7
• Insulin should be kept in a temperature-controlled environment between 36°F and 86°F.4,7
• Rotation of injection sites is necessary to prevent lipodystrophy.4,7
• It is recommended that patients stick with 1 approved anatomical site for all insulin injections, such as the abdomen or leg, to maintain consistent pharmacokinetics.4,13,14
It is also important to know the constitution of the different insulins and whether they have been compromised. For example, if a clear solution insulin turns cloudy, it is considered compromised and should be thrown away.
CONCLUSION
Patients are diagnosed every day with diabetes, and many treatment regimens include insulin therapy. With the diagnosis of diabetes, patients are given extensive information on therapy, nutrition, preventative measures, and technique. Since controlling diabetes can call for intensive insulin therapy, medication administration instruction by HCPs is important. It is important to discuss in detail how the patient manages their insulin therapy at each visit so that issues will not be overlooked. Long-term, inappropriate use of insulin may lead to uncontrolled diabetes.
Diabetes is a complex disease to manage and takes a joint effort by both the HCP and patient to control. Patients need to understand the importance of compliance in all aspects of the disease, and the HCP needs to understand the importance of extensive counseling, including diet, exercise, and medication therapy.
Author disclosures
The authors report no actual or potential conflicts of interest with regard to this article.
Disclaimer
The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the U.S. Government, or any of its agencies. This article may discuss unlabeled or investigational use of certain drugs. Please review the complete prescribing information for specific drugs or drug combinations—including indications, contraindications, warnings, and adverse effects—before administering pharmacologic therapy to patients.