PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
Drug Affecting the Cardiovascular System
DRUGS USED TO TREAT DYSLIPIDEMIAS
ATHEROSCLEROSIS:
Atherosclerosis is one of the major treatable causes of CAD (Coronary artery
disease) characterized by the accumulation of fatty deposits on the inner walls of
the arteries and arterioles throughout the body that reduces the blood supply to
vital organs, resulting in strokes, angina pectoris, myocardial infarction, and
peripheral vascular disease.
A primary cause of atherosclerosis is the abnormal elevation of cholesterol and
triglyceride levels in the blood as part of a disease known as hyperlipidemia.
Dyslipidemias are defined as abnormalities that involve one or more of the blood
fats (lipids).
Dyslipidemias can be the result of genetic abnormalities, secondary causes (e.g.,
lifestyle, drugs, underlying diseases), or both. A diet that is high in saturated
fats, cholesterol, carbohydrates, total calories, and alcohol as well as a sedentary
lifestyle contribute significantly to dyslipidemias.
TREATMENT OF HYPERLIPIDEMIAS
Some of the most common hyperlipidemias of genetic origin are treatable with
medicines (Table 22-2).
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
The primary treatment of hyperlipidemia is with what are called therapeutic
lifestyle changes (TLCs), which include weight reduction, exercise, and a diet
that is low in cholesterol and fat.
If a good trial of changes in diet and exercise habits does not produce an
acceptable decrease in blood lipid levels, antilipemic agents may be added to the
patient’s regimen.
In general, for every 1% reduction in the LDL level, there is a 1% reduction in
the rate of coronary artery disease events.
DRUG THERAPY FOR HYPERLIPIDEMIAS
Selection of initial antilipemic therapy depends on the type of dyslipidemia
present.
Pharmacologic antilipemic therapy is often started with a statin because of their
safety record and success in lowering cholesterol levels. The statins are the most
potent and highly effective drugs for lowering LDL-C levels, and they appear to
be relatively safe. However, they are substantially more expensive than other
treatments.
Prescription-strength niacin is effective for lowering total cholesterol and
triglyceride levels and for raising HDL-C levels.
After starting drug therapy, the LDL-C level should be measured at 4 to 6 weeks
and again at 3 months.
If the response to initial drug therapy is inadequate, the dosage of the statin
should be increased or another drug should be added to the treatment regimen.
The combination of a bile-acid–binding resin with either niacin or a statin can
potentially lower LDL-C levels by 40% to 50%.
In rare cases of particularly high cholesterol levels, triple therapy with a bile-
acid–binding resin, niacin, and a statin may be required. Drug therapy is likely to
continue for many years or the patient’s lifetime; plasma lipid levels return to
pretreatment levels after 2 to 3 weeks if therapy is discontinued.
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
DRUG CLASS: BILE-ACID–BINDING RESINS
ACTIONS:
Cholestyramine and colestipol are resins that bind bile acids in the intestine,
after oral administration, they forms a non-absorbable complex with bile acids,
preventing the enterohepatic recirculation of the bile acids.
Removal of bile acids causes liver cells to compensate, by increasing the
metabolism of cholesterol to produce more bile acids, which results in a net
reduction in the total cholesterol level.
USES
To decrease elevated cholesterol concentrations.
To reduce the risks of atherosclerosis leading to CAD.
For the treatment of pruritus secondary to partial biliary stasis.
Diarrhea secondary to excess fecal bile acids or pseudomembranous
colitis.
Digitalis glycoside toxicity.
THERAPEUTIC OUTCOMES
The primary therapeutic outcomes expected from bile acid–binding resin therapy
are the reduction of the LDL and total cholesterol levels.
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
Nursing Implications for Bile-Acid–Binding Resins
Premedication Assessment
1. Serum triglyceride and cholesterol levels should be determined before the
initiation of therapy and periodically thereafter.
2. Obtain patient data related to any GI alterations before the initiation of
therapy (e.g., the presence of abdominal pain, nausea, flatus).
Monitoring:
Common Adverse Effects:
Gastrointestinal: Constipation, Bloating, Fullness, Nausea, Flatulence.
These adverse effects can be minimized by:
starting with a low dose.
mixing the drug with noncarbonated juices or sauces.
swallowing the drug without gulping air.
Maintain adequate fiber in the diet, and drink sufficient water.
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
DRUG CLASS: NIACIN
ACTIONS:
Niacin, also known as nicotinic acid, is a water-soluble B vitamin (also known
as vitamin B3).
Its mechanisms of action as an antilipemic agent are not completely known, but
they are not related to its effects as a vitamin. Niacin inhibits VLDL synthesis by
liver cells, which causes a decrease in LDL and triglyceride production. Niacin
may also reduce the metabolism of HDL, thereby causing increase in HDL
levels.
NURSING IMPLICATIONS FOR NIACIN
Premedication Assessment
1. Serum triglyceride and cholesterol levels should be determined before
initiation of therapy and periodically thereafter.
2. Liver function tests (bilirubin, aspartate aminotransferase [AST], alanine
aminotransferase [ALT], gamma-glutamyl transferase [GGT], alkaline
phosphatase levels, and prothrombin time) should be determined before
initiating therapy and every 6 to 8 weeks during the first year of therapy.
3. Baseline uric acid and blood glucose levels should be determined before
initiating therapy.
[Niacin therapy may induce hyperuricemia, gout, and hyperglycemia in
susceptible patients].
4. Baseline blood pressure and heart rate should be determined before initiating
therapy.
5. Obtain patient data related to any GI alterations before initiating therapy (e.g.,
the presence of abdominal pain, nausea, or flatus).
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
Monitoring
1-Common Adverse Effects
Flushing, itching, and rash.
Neurologic: Tingling and headache.
Gastrointestinal: Nausea, Gas, and Abdominal Discomfort and Pain.
Cardiovascular: Dizziness, Faintness, Hypotension.
These adverse effects can be minimized by:
Taking aspirin (325 mg) or ibuprofen (200 mg) 30 minutes before each
dose of niacin.
Starting with low doses and administering all doses with food
Teach the patient to rise slowly from a supine or sitting position.
Monitor blood pressure.
2-Serious Adverse Effects:
Hepatobiliary: Hepatotoxicity.
Gastrointestinal: Anorexia, Nausea, Malaise, Jaundice.
[These are the early symptoms that are associated with hepatotoxicity.
Musculoskeletal: Myopathy.
Report these to the health care provider for further evaluation.
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
DRUG CLASS: HMG-CoA REDUCTASE INHIBITORS
ACTIONS:
HMG-CoA reductase enzyme inhibitors (atorvastatin, fluvastatin, rosuvastatin..)
are the most potent antilipemic agents available; they are also known as statins.
The statins competitively inhibit the enzyme that is responsible for converting
HMG-CoA to mevalonate in the biosynthetic pathway to cholesterol in the liver.
The reduction in liver cholesterol increases the removal of LDLs from the
circulating blood.
These agents are more effective if administered at night because peak production
of cholesterol occurs at this time.
Statins also have other beneficial effects unrelated to their lipid-lowering
capacity: they reduce inflammation, platelet aggregation, thrombin formation,
and plasma viscosity, thereby reducing the factors that contribute to heart attacks
and strokes.
NURSING IMPLICATIONS FOR HMG-COA REDUCTASE INHIBITORS
Premedication Assessment
1. Serum triglyceride and cholesterol levels should be determined before
initiating therapy and periodically thereafter.
2. Liver function tests (AST, ALT) should be obtained before initiating therapy,
every 4 to 6 weeks during the first 3 months of therapy, every 6 to 12 months
during the next 12 months or after dose elevation, and every 6 months thereafter.
3. Obtain data related to any GI alterations before initiating therapy (e.g.,
presence of abdominal pain, nausea, or flatus).
4. Confirm that the patient is not pregnant before initiating a statin.
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
Monitoring
1-Common Adverse Effects:
Neurologic: Headaches.
Gastrointestinal: Nausea, Abdominal Bloating, Gas.
These symptoms are usually mild and they disappear with continued therapy.
2-Serious Adverse Effects:
Gastrointestinal: Liver Dysfunction.
Musculoskeletal: Myopathy, Rhabdomyolysis.
[Rhabdomyolysis is a very serious condition in which kidney damage results
from progressing myopathy. An early indication of rhabdomyolysis is pinkish or
red-tinged urine secondary to myoglobin (muscle protein) passing through
damaged glomeruli into the urine (myoglobinuria).]
Report these symptoms to the health care provider for further evaluation.
PHARMACOLOGY DILVEEN MOSSA
16/2/2017 M.Sc. PHARMACOLOGY
DRUG CLASS: FIBRIC ACIDS
ACTIONS
The mechanism of action of the fibric acids (e.g., gemfibrozil, fenofibrate) is
unknown; however, they do lower triglyceride levels in patients with
hypertriglyceridemia and raise HDL levels. They also reduce LDL-C by in
patients with elevated cholesterol.
[Fenofibrate may lower LDL-C levels more effectively than gemfibrozil].
NURSING IMPLICATIONS FOR FIBRIC ACIDS
Premedication Assessment
1.Serum triglyceride and cholesterol levels should be measured before initiating
therapy and periodically thereafter
2.Liver function tests should be run before initiating therapy and then every 6
months thereafter.
3. Baseline blood glucose levels should be determined before gemfibrozil
therapy.
[Gemfibrozil may cause moderate hyperglycemia.]
4. Obtain patient data related to any GI alterations before initiating therapy (e.g.,
presence of abdominal pain, nausea, flatus).
Monitoring
1-Common Adverse Effects:
Gastrointestinal: Nausea, Diarrhea, Flatulence, Bloating, Abdominal Distress.
Starting with a lower dosage taken between meals can help to minimize these
effects
2-Serious Adverse Effects
Gastrointestinal: Anorexia, Nausea, Malaise, Jaundice.
Musculoskeletal: Myopathy.
Report these symptoms to the health care provider for further evaluation
GOOD LUCK