Page 860 - Cardiac Nursing

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836 PA R T V / Health Promotion and Disease Prevention
found to increase the risk of stroke and did not affect CVD inci- (statins), fibric acid derivatives, and the intestinal absorption
dence. As a result, conjugated equine estrogen is not recommended blockers. Individual response to each of these agents is variable,
for prevention of chronic disease in postmenopausal women. 123 and each of the agents has potential side effects. Nursing can
The 2007 AHA guidelines for the primary and secondary preven- play a major role in the management of patients by assisting the
tion of heart disease in women support these conclusions. 124 patient to minimize side effects while promoting adherence to
the regimen that achieves the desired lipid profile. In this sec-
tion, the action, indications for use, and specific adherence
PHARMACOLOGIC strategies for each of the classes of hypolipidemic drugs are re-
MANAGEMENT OF viewed (Table 36-10).
HYPERLIPIDEMIA Bile Acid-Binding Resins
Actions and Indications for Use. Bile acid-binding resins
The primary rationale for the treatment of hyperlipidemia is the are insoluble in water and are not absorbed from the intestine.
reduction of CVD morbidity and mortality. Studies using hy- These agents bind with bile acids in the intestine, forming an in-
polipidemic drug therapy to achieve LDL reductions have soluble complex. The enterohepatic circulation of bile acids is in-
demonstrated lower CVD morbidity and mortality and lower terrupted and fecal excretion of bile acids is increased. This results
overall mortality rates. 8,10 Angiographic studies using lipid-lower- in increased synthesis of bile acids from hepatic cholesterol stores.
ing drugs have demonstrated less progression of angiographically Reduced hepatic cholesterol stimulates LDL receptor formation
determined CVD with reduction of LDL. 125–128 The rate of pro- and increases HMG-CoA reductase activity, resulting in increased
gression of CVD appears to be a dose-related response, with extraction of LDL from the bloodstream and a lower plasma con-
slower rates of progression associated with greater LDL lowering. centration of LDL. Hepatic production of VLDL is also en-
Meta-analytic techniques have been used to analyze lipid-low- hanced, resulting in increased triglyceride levels. The expected re-
ering studies and suggest that the decrease in CVD mortality is sponse to resin therapy is seen in 2 to 4 weeks and may result in a
offset by increased death rates from other causes, particularly can- 20% to 25% reduction in LDL. 20
cer deaths and non-illness-related deaths such as injury deaths and
suicides. 129–131 These meta-analyses did not include data from the Strategies for Increased Efficacy and Adherence. The ma-
more recent very large clinical trials investigating lipid-lowering jor side effect of the bile acid-binding resins is constipation; the
drugs. 7,8,10 These studies did not observe any increase in cancer or resins can be unpalatable, which may affect compliance. Resins
non-illness-related deaths. Although the explanations for these come in both powder and tablet formulations. In powder form,
findings remain controversial, the consensus of experts is that hy- the resins must be mixed with water. Because they are insoluble,
polipidemic drug therapy should always be instituted with non- they form a gritty solution. It is helpful to demonstrate the mix-
pharmacologic interventions (TLC), including a low-fat, low- ing process and allow the patient to taste the drug as part of the
cholesterol diet, regular exercise, weight control, smoking prescription process. If constipation develops, instruct the pa-
cessation, control of hypertension, and control of blood glucose tient in the use of fiber, stool softeners, and other hygienic meas-
(in patients with diabetes). Hypolipidemic drug therapy requires ures, such as increased fluid intake. Bile acid-binding resins
careful consideration of individual risks as well as the benefits of should be taken with meals, particularly with the largest meal of
such drug therapy. There is sufficient evidence that lowering LDL the day, because intestinal bile acids are greatest during that time.
cholesterol, particularly with the use of HMG-CoA reductase in- Because these drugs are binding agents, they have the potential to
hibitors, in persons with known CAD and with CAD equivalents bind and interfere with the absorption of other medications.
provides substantial benefit to reduced morbidity and mortality. Consequently, the patient should be instructed to take other
medications 1 hour before or 4 hours after taking the resin. Re-
viewing the mechanism of action with the patient promotes ad-
Lipid Criteria and Goals for herence and a better understanding of the rationale for these in-
Drug Therapy structions.
Consideration of hypolipidemic drug therapy for primary preven- Nicotinic Acid (Niacin)
tion (i.e., in people without existing CVD) is indicated in those
without CVD risk factors but with LDL levels of 190 mg/dL or Actions and Indications for Use. Nicotinic acid, or niacin,
more, or in people with 0 to 1 CVD risk factors and LDL levels is a vitamin B 3 derivative that in large doses blocks the release of
of 160 mg/dL or more. The target goals of treatment should be to free fatty acids from adipose tissues, resulting in less hepatic con-
132
achieve LDL levels of less than 160 or 130 mg/dL, respectively. In version of free fatty acids into triglycerides.
secondary prevention (i.e., in patients with established CVD, with The hepatic production of VLDL is also decreased. Because
CVD equivalents, and/or a CVD risk of 20% in 10 years), drug VLDL is converted to IDL and LDL, decreased VLDL levels lead
therapy can be considered if LDL levels are more than 100 mg/dL to favorable reductions in these lipoproteins as well. Contraindi-
and should be initiated if LDL levels are more than 130 mg/dL. cations to use include active liver disease and peptic ulcer disease,
The optimal LDL goal for all adults, in particular for those with and caution should be exercised when it is used in patients with
3
established CVD , less than 100 mg/dL (see Table 36-10). diabetes and atrial arrhythmias.
Strategies for Increased Efficacy and Adherence. The
Classes of Hypolipidemic Drugs most common side effect of nicotinic acid use is cutaneous
flushing caused by a prostaglandin-mediated vasodilation effect
The major classes of hypolipidemic drugs include the bile acid- on vascular smooth muscle. This effect can be minimized with
binding resins, nicotinic acid, HMG-CoA reductase inhibitors the use of aspirin taken 30 minutes before the nicotinic acid