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

Acarbose works here

Glucose Amino acids

glycogen

proteins

Sulfonylureas and repaglinide work here

Stomach

Diazoxide, glucagon and metformin work here

Glucose absorbed

alpha cells

beta cells

Exenatide works here

delta cells

Pancreas

GLP-1 release

Insulin released

Replacement insulin works

Broken down by DPP-4

Decreased glucose level

Cells

Insulin receptor sites

Sitagliptin works here

Insulin, pioglitazone and rosiglitazone work here

FIGURE 38.3  Sites of action of drugs used to treat diabetic conditions.

Safe medication administration

pregnancy and breastfeeding to monitor glucose levels closely and adjust the insulin dose accordingly. Insulin does not cross the placenta; therefore, it is the drug of choice for managing diabetes during pregnancy. Insulin does enter breast milk, but it is destroyed in the GI tract and does not affect the breastfeeding infant. However, insulin-dependent mothers may have inhibited milk production because of insulin’s effects on fat and protein metabolism. The effectiveness of breastfeed- ing the infant should be evaluated periodically. People with allergies to beef or pork products should use only human insulins. Insulin is usually given by subcutaneous injection. Using an insulin syringe with a 25-gauge, 1.3-centimetre needle, inject the insulin into the loose connective tissue underneath the skin (Figure 38.4). The areas of the body that are best able to be pinched up to access this tissue are the abdomen, the upper thigh and the upper arm. Inject the needle quickly at an angle of 45° to 90°, depending on the amount and turgor of the tissue. Inject the insulin. Remove the needle and syringe and apply gentle pressure at the injection site. Rotate sites regularly to prevent tissue damage. Insulins should only be drawn up into insulin-specific syringes due to potential for drug errors with regular syringes.

Adverse effects The most common adverse effects related to insulin use are hypoglycaemia and ketoacidosis, which can be con- trolled with proper dose adjustments. Local reactions at injection sites, including lipodystrophy, can also occur. Clinically important drug–drug interactions Caution should be used when giving a person stabil­ ised on insulin any drug that decreases glucose levels FIGURE 38.4  Inject the needle quickly at an angle of 45° to 90°, depending on the amount and turgor of the tissue. [Photo by Rick Brady. With permission from Taylor, C., Lillis, C. & LeMone, P. (2005). Fundamentals of Nursing: The Art and Science of Nursing Care (5th edn). Philadelphia: Lippincott Williams & Wilkins.]