.Therapeutic Class: Drug for hypertension and angina
Pharmacologic Class: Calcium channel blocker.
ACTIONS AND USESNifedipine is CCB generally prescribed for HTN and variant or vasospastic angina. It is occasionally used to treat Raynaud's phenomenon and hypertrophic cardiomyopathy. Nifedipine acts by selectively bloking calcium channels in myocardial and vascular smooth muscle, including those in the coronary arteries. This results in less oxygen utilization by the heart, an increase in cardiac output, and a fall in blood pressure. It is available as extended-release tablets (XL).ADMINISTRATION ALERTSDo not administer immediate-release formulations of nifedipine if an impending MI is suspected, or within 2 weeks following a confirmed MI.Administer nifedipine capsules or tablets whole . If capsules or extended-release tablets are chewed, divided, or crushed, the entire dose will be delivered at once.Pregnancy category C .PHARMACOKINETICS Onset:10-30 min PO
Duration:4-8 h(24 h extended release)
* ADVERSE EFFECTSAdverse effects of nifedipiine are generally minor and are related to vasodilation such as headache, dizziness, peripheral edema, and flushing. Immediate-acting forms of nifedipine can cause reflex tachycardia. To avoid rebound hypotension, the drug should be discontinued gradually. In rare cases, nifedipine may cause a paradoxical increase in anginal pain, possibly related to hypotension or heart failure.Contraindications: the only contraindication is prior hypersensitivity to nifedipine.INTERACTIONSDrug- Drug: when given concurrently, other antihypertensives have additive effects with nifedipine on blood pressure. Concurrent use of nifedipine with a beta blocker increases the risk of congestive heart failure. Nifedipine may increase serum levels of digoxin, leading to bradycardia and digoxin toxicity. Alcohol potentiates the vasodilating action of nifedipine, and could lead to syncope caused by a severe drop in blood pressure.Lab Tests: May increase values for the following lab tests:alkaline phosphatase, LDH, ALT, CPK, and AST.Herbal/Food: Grapefruit juice may enhance the absorption of nifedipine. Melatonin may increase blood pressure and heart reat.Teratment of Overdose: The most likely sign of overdosage is hypotension, which is treated with vasopressors. Calcium infusions may be indicated.NURSING PROCESS FOCUSAssessmentBaseline assessment prior to administration:Understand the reason the drug has been pres cribbed in order to assess for therapeutic effects.Obtain acomplete health history including cardiovascular (including Ml,heart failure), musculoskeletal (pre- existing conditions that might result in fatigue, weakness, muscle or joint pain), and the possibility of pregnancy . Obatain adrug history including allergirs, current prescriptionand OTC drugs, herbal preparations, and alcohol use. Be aler to possible drug interactions.Evaluate appropriate laboratory findings,electrolytes, especially potassium level , liver function studies, and lipid profiles. Obtain baseline weight, vital signs (especially BPand pulse ) breath sounds, and cardiac monitoring (e.g., ECG,cardiac output) if appropriate. Assass for location and character/amount of edema, if present .Assessment throughout administration:Assess for desired therapeutic effects(e.g, lowered blood pressure within established limits; also lessened or absent angina and dysrhythmias if present).Continue periodic monitoring of electrolytes, especially potassium.Assess for weakness, flushing, dizziness, or sexual dysfunction. Myalgia, arthralgia, peripheral or facial edema, significant constipation, inability to maintain ADLs due to musculoskeletal weakness or pain, and unexplained numbness or tingling of extremities should be reported immediately to the health care provider.Potential Nursing DiagnosesDecreased Cardiac Output (disease...