McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 4 7 Lipid-lowering agents

■ ■ Monitor the results of laboratory tests, including serum cholesterol and lipid levels, to evaluate the effectiveness of drug therapy.

Prototype summary: Cholestyramine Indications: Reduction of elevated serum cholesterol in people with primary hypercholesterolaemia; pruritus associated with partial biliary obstruction. Actions: Binds with bile acids in the intestine, allowing excretion in faeces instead of reabsorption, causing cholesterol to be oxidised in the liver and serum cholesterol levels to fall. Pharmacokinetics: Not absorbed systemically. T 1/2 : Not absorbed systemically, excreted in faeces. Adverse effects: Rash, headache, anxiety, vertigo, dizziness, constipation due to faecal impaction, exacerbation of haemorrhoids, cramps, flatulence, nausea, increased bleeding tendencies, vitamin A and D deficiencies, muscle and joint pain. ■ ■ Assess for contraindications or cautions: known allergies to these drugs to avoid hypersensitivity reactions ; impaired intestinal function, which could be exacerbated by these drugs ; biliary obstruction, which could block the effectiveness of these drugs ; and current status related to pregnancy and breastfeeding because of the potential for adverse effects on the fetus or breastfeeding baby . ■ ■ Perform a physical assessment to establish a baseline before beginning therapy and during therapy to determine the effectiveness of therapy and evaluate for any potential adverse effects. ■ ■ Weigh the person to establish a baseline and evaluate for changes reflecting lifestyle changes that accompany drug therapy . ■ ■ Inspect the person’s skin for colour, bruising and rash to evaluate for possible adverse effects. ■ ■ Assess neurological status, including level of orientation and alertness, to determine any central nervous system effects. ■ ■ Monitor pulse and blood pressure for changes related to changes in CAD risk factors. ■ ■ Inspect the abdomen for distension and auscultate bowel sounds for changes in gastrointestinal motility. ■ ■ Assess bowel elimination patterns, including frequency of stool passage and stool characteristics, to identify possible constipation and faecal impaction. Care considerations for people receiving bile acid sequestrants Assessment: History and examination

Implementation with rationale

■ ■ Do not administer powdered agents in dry form; these drugs must be mixed in fluids to be effective. Mix with fruit juices, soups, liquids, cereals or pulpy fruits. Mix colestipol, but not cholestyramine, with carbonated beverages. Stir, and encourage the person to swallow all of the dose. ■ ■ If the person is taking tablets, ensure that tablets are not cut, chewed or crushed because they are designed to be broken down in the GI tract; if they are crushed, the active ingredients will not be effective. Urge the person to swallow tablets whole with plenty of fluid. ■ ■ Give the drug before meals to ensure that the drug is in the GI tract with food. ■ ■ Administer other oral medications 1 hour before or 4 to 6 hours after the bile sequestrant to avoid drug–drug interactions. ■ ■ Arrange for a bowel program as appropriate to effectively deal with constipation if it occurs. ■ ■ Provide comfort measures to help the person tolerate the drug effects. These include small, frequent meals to reduce the risk of nausea; ready access to bathroom facilities to prevent constipation; safety precautions to prevent injury if dizziness, central nervous system (CNS) changes or bleeding is a problem; replacement of fat-soluble vitamins; skin care as needed; and analgesics for headache. ■ ■ Offer support and encouragement to help the person deal with the diagnosis and the drug regimen and lifestyle changes that may be necessary; refer to services that might help with the high cost of these drugs. ■ ■ Provide thorough teaching, including the name of the drug, dosage prescribed and schedule for administration; method to administer the drug, such as mixing the powder form in fluids or taking tablets whole (without crushing, chewing or cutting); appropriate fluids for mixing drug; measures to avoid adverse effects, warning signs of problems, and the need for follow-up laboratory testing to monitor cholesterol and lipid levels; dietary and lifestyle changes for risk reduction ; and monitoring and evaluation to enhance knowledge about drug therapy and to promote compliance.