McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 3 8 Agents to control blood glucose levels

TABLE 38.2

DRUGS IN FOCUS Insulin

Drug name

Dosage/route

Usual indications

Varies based on response, diet, and activity level

Treatment of type 1 diabetes mellitus; treatment of type 2 diabetes mellitus in people whose diabetes cannot be controlled by diet or other agents; treatment of severe ketoacidosis or diabetic coma; treatment of hyperkalaemia (in conjunction with a glucose infusion to produce a shift of potassium into the cells [polarising solution]); also used for short courses of therapy during periods of stress (e.g. surgery, disease) in people with type 2 diabetes, for newly diagnosed people being stabilised, for people with poor control of glucose levels, and for people with gestational diabetes

insulin (various types)

of insulin delivery that are available or under study for future use. Hyperglycaemic crisis Therapeutic actions and indications Insulin is a hormone that promotes the storage of the body’s fuels, facilitates the transport of various metabo- lites and ions across cell membranes and stimulates the In 2009, lente insulin was removed from the market as name confusion had occurred between Lantus insulin and lente insulin. The pharmacokinetics and dose of insulins vary greatly. Use caution to make sure you know which insulin is intended for the individual person. Lantus and Levemir insulin cannot be mixed in a syringe with any other insulin or any other drug. Use particular caution when working with these two insulins. The DHBNZ Safe and Quality Use of Medicines has released an alert informing healthcare professionals to take extra care when giving insulin Humalog preparation. There are three Humalog preparations available in Australia and New Zealand: Humalog, Humalog Mix25 and Humalog Mix50. Potential harm can result if a person is given Humalog rapid release as opposed to Humalog intermediate release. The Australian Commission on Safety and Quality in Health Care (ACSQHC) has developed 10 National Safety and Quality Health Service Standards. These Standards aim to improve the quality of health service provision across Australia and provide a national statement of the level of care consumers should be able to expect from health services. Awareness and knowledge of Standard 4 on Medication Safety is an important part of the nurse’s and midwife’s clinical repertoire. For more information, see www.safetyandquality.gov.au/our-work/accreditation/nsqhss. Safe medication administration

synthesis of glycogen from glucose, of fats from lipids and of proteins from amino acids. Insulin does these things by reacting with specific receptor sites on the cell. Figure 38.3 shows the sites of action of replacement insulin and other drugs used to treat diabetic conditions. See Table 38.2 for indications. Pharmacokinetics Various preparations of insulin are available to provide short- and long-term coverage. These preparations are processed within the body like endogenous insulin. However, the peak, onset and duration of each vary because of the placement or addition of glycine and/or arginine chains. Maintenance doses are given by the subcutaneous route only, and injection sites need to be rotated regularly to avoid damage to muscles and to prevent subcutaneous atrophy. Regular insulin is given intramuscularly or intravenously in emergency situations. Insulin is available in various preparations with a wide range of peaks and durations of action. A person may receive a combination of regular and isophane insulin in the morning to cover the glucose peak from breakfast (regular onset, 30 to 60 minutes) and the lunch and dinner glucose peaks. The person may then require another injection before bed. The types of insulin used are determined by the anticipated eating and exercise activities of any particular individual. It is very important to make sure that one is using the correct insulin preparation when administering the drug. Insulin glargine ( Lantus ) and insulin detemir ( Levemir ) cannot be mixed in solution with any other drug, including other insulins. Contraindications and cautions Because insulin is used as a replacement hormone, there are no contraindications. Care should be taken during