Drug Topics - November 19, 2007 - (Page 27)

27 of insulin and the remaining one-third should be administered before dinner. The mixture of insulin NPH to mealtime insulin should be in a 2:1 ratio for the morning dose and in a 1:1 ratio for the evening dose. The main advantage of this regimen is the low number of required injections per day. Disadvantages of this insulin regimen include poor peaking of noon insulin and excess insulin at night. To help minimize these effects, the patient should limit the quantity of carbohydrates ingested at lunch to decrease the risk of daytime hyperglycemia and eat a bedtime snack to reduce the risk of nocturnal hypoglycemia. If the fasting blood glucose goal cannot be achieved without nocturnal hypoglycemia while on a two-injection regimen, the dose of insulin NPH may be moved from before dinner to a separate injection at bedtime. Advantages of this three-injection regimen include less nocturnal hypoglycemia and improved control of fasting blood glucose. A disadvantage of this insulin regimen is poor peaking of noon insulin. Again, this may be controlled with a low-carbohydrate lunch. If the three-injection regimen does not provide adequate control, an additional dose of mealtime insulin should be given before lunch. This four-injection regimen most closely mimics the physiologic pattern of normal insulin secretion. However, this regimen requires that patients have a strong commitment to frequently monitoring their blood glucose. Some clinicians prefer to start patients on an intensive regimen of three or more injections to reinforce the importance of glycemic control from the outset, rather than change strategies over time due to the inability to achieve therapeutic goals with two-injection regimens. However, children and pubescent adolescents are relatively protected from microvascular complications and may be initially managed with the less intense two-injection regimen. Regardless of the injection regimen used, the maintenance insulin dose should be adjusted based on fasting blood glucose levels, and mealtime insulin doses should be adjusted based on postprandial blood glucose (taken two hours after meals). Slidingscale insulin regimens are based on the concept of treating high blood sugars with additional mealtime insulin. Implementing sliding-scale insulin regimens for the hospitalized patient has demonstrated improved outcomes and is therefore recommended. However, sliding-scale insulin treatment of high blood sugars can result in a roller-coaster effect of highs and lows in the outpatient setting. Instead, patients should be counseled to adjust the dose of mealtime insulin based on meal size to prevent hyperglycemia or hypoglycemia. A general guideline for adjusting mealtime insulin is to increase or decrease the dose by 1 to 3 units for every 50 mg/dL increase or decrease from the desired blood glucose target. Patients who count carbohydrates may use 1.0 to 1.5 units of mealtime insulin for every 10 gm of carbohydrate consumed. If a meal is omitted, then patients should skip their mealtime insulin. Remember, these are only guidelines, and after patients obtain experience with self-management of their diabetes, they will learn how to appropriately adjust their insulin. place emphasis on achieving glycemic control as soon as possible. After diagnosis of diabetes, patients should begin lifestyle modifications and metformin 500 mg once or twice daily. If metformin is tolerated well after one week of therapy, the dose is titrated to 850 mg to 1000 mg twice daily. If the hemoglobin A1c (A1c) remains greater than or equal to the goal of 7%, the guidelines recommend adding maintenance insulin, a sulfonylurea, or a glitazone. If the A1c is greater than 8.5%, insulin should be used in addition to metformin. If the A1c is less than or equal to 8.5%, either a glitazone or a sulfonylurea may be added. If glycemic control is not achieved with dual therapy, a third oral agent may be considered if the A1c is close to goal (A1c 250 mg/dL, random glucose levels > 300 mg/dL, A1c > 10% or the presence of ketonuria, or symptomatic diabetes with polyuria, polydipsia, and weight loss. After the symptoms of hyperglycemia are relieved, oral medications may be added, and it may be possible to withdraw insulin. Maintenance insulin should be initiated at a dose of 10 units or 0.2 units/kg and adjusted as described in Table 2 every three to seven days until the fasting blood sugar is between 70 and 130 mg/dL. The dose of insulin should be reduced by greater than or equal to 4 units (or by 10% if the dose is greater than 60 units) if the patient obtains a blood sugar less than 70 mg/dL or experiences symptoms of hypoglycemia at anytime during the previous week. If the A1c remains above goal after two to three months of insulin titration, the patient should use an additional injection of insulin based on results of monitoring pre-lunch, pre-dinner, and pre-bedtime blood sugars. If hyperglycemia is present before lunch, two options are available to the patient. Either a dose of mealtime insulin or a dose of premixed insulin may be used before breakfast. If hyperglycemia is present before dinner, a second dose of maintenance insulin (insulin NPH or insulin detemir) may be given before breakfast. If hyperglycemia is present before dinner for a patient using insulin glargine, a dose of mealtime insulin may be given before lunch. If hyperglycemia is present before bedtime, either a dose of mealtime insulin may be given before dinner or the patient’s bedtime maintenance insulin may be changed to a premixed insulin before dinner. In all of these examples, an appropriate starting dose of mealtime insulin is 4 units. If the A1c continues to remain above goal after two to three months of adjustments, two-hour postprandial blood glucose levels should be monitored and adjustments of mealtime insulin should be made based on patterns revealed from logs of self-monitored blood glucose. According to the American Diabetes Association, the goal two-hour postprandial blood glucose level is less than 180 mg/dL. Appropriate insulin use with Type 2 diabetes In the August 2006 issue of Diabetes Care, the American Diabetes Association and the European Association for the Study of Diabetes published consensus guidelines for the initiation and adjustment of therapy for the management of hyperglycemia in patients with Type 2 diabetes. These guidelines Patient education Patient counseling is an excellent opportunity for pharmacists to help patients optimize the appropriate use of insulin and increase the likelihood of achieving therapeutic goals. Insulin NPH and premixed insulin preparations are suspensions; therefore, patients should suspend the insulin by gently rolling the insulin in their hands or by inverting the vial or pen 10 times. Patients should not shake the insulin. Needles should be used only once with insulin

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Drug Topics - November 19, 2007 Contents Latebreakers Letters Leukemia Patients Now Have More Options First-in-Class HIV Drug Boon to Patients at End of Tether 150 Years of American Pharmacy Pharmacy Schools Confront New Pressures From Pariah to Patient ACCP Releases Position Paper on Ethical Interactions New Injectable Antibiotic Welcomed with Open Arms NCCN Updates Head and Neck Cancer Guide Improved Phosphate Binder Approved for Dialysis Patients Considering Combination Concern Ensuring Seamless Care Bill Would Create Center for Comparative Effectiveness Hospital Improves Patient Safety with Automatic Drug Distribution System Infection Rates, Patient Stays Drop with New Drug Device How R.Ph.s Helped Three Hospitals Win Quality and Safety Awards A Pharmacist and Dog in Tow are Alzheimer’s Patients’ Best Friends More PBMs Agreeing to Pricing Transparency New Insulins in the Management of Diabetes New Products Advertisers Index Classified VIEWPOINT: Reflections on Pharmacy School After 30 Years

Drug Topics - November 19, 2007

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