Prevalence of insulin glargine vial use beyond 28 days in a Medicaid population.

OBJECTIVES: Insulin glargine, one of the most commonly prescribed drugs for diabetes, has a 28-day limit on the use of a 10-mL (1000 units) multiple-dose vial once the bottle is punctured. If patients who are using smaller doses or are not adherent continue to use insulin glargine beyond the 28-day window, it can result in questionable stability and sterility of the product. The aim of this study was to determine the proportion of patients who used each insulin glargine vial for more than 28 days, the mean number of days the vial was used after 28 days, the reason for the extended use, and whether that use had any association with diabetes control and injection site infection. METHODS: The study was conducted in 2 phases. Phase I was a retrospective database analysis of insulin glargine 10-mL vial use by the adult Medicaid population with type 2 diabetes served by Molina Healthcare to determine the proportion of patients who used each vial beyond 28 days. Phase II was a cross-sectional telephone interview to identify the reasons for the extended use. RESULTS: Of the 269 patients identified, 81% used it for more than 28 days, with a mean of 43 days. Of the interviewed patients, 60% did not discard the vials after 28 days because of a lack of awareness. Patients who were aware of the 28-day limit were informed by a pharmacist or diabetes educator. CONCLUSION: A large proportion of Medicaid patients were found to use insulin glargine past the recommended 28-day limit. More work is needed with a larger sample size to determine whether reasons besides lack of awareness affect the use of insulin glargine beyond its expiration and the role of pharmacists and diabetes educators in improving adherence to disposing of the drug after 28 days.

Warfarin knowledge in patients with atrial fibrillation: implications for safety, efficacy, and education strategies.

BACKGROUND: Multiple factors influence warfarin metabolism and can significantly affect the risk of adverse events. The extent to which patients understand the modifiable factors that impact on warfarin safety and efficacy is unclear. METHODS: A 52-item questionnaire related to knowledge of warfarin was administered to patients with atrial fibrillation in a face-to-face interview with a dietitian. Results were compiled based on five categories: general warfarin knowledge, compliance, drug interactions, herbal or vitamin interactions, and diet. RESULTS: 100 patients were surveyed. Stroke risk factors included hypertension (57%), heart failure (36%), age >75 years (33%), diabetes (22%), and prior stroke/transient ischemic attack (29%). The majority were either high-school (49%) or college graduates (27%). Ten (10%) had a stroke while on warfarin, 11 (11%) had a blood transfusion, and 26 (26%) had at least one fall. The percentages correct for questionnaire items in the five categories were as follows: general knowledge (62%), compliance (71%), drug interactions (17%), herbal or vitamin interactions (7%), and diet (23%). Neither education level nor duration of therapy correlated with warfarin knowledge. Patients at highest risk of stroke had very low knowledge scores in general. DISCUSSION: Patients on warfarin have a poor general understanding of the medication, particularly those at highest risk of stroke.