felodipine

felodipine

(fell oh' di peen)

Plendil, Renedil (CAN)

Pregnancy Category C

Drug classes

Calcium channel-blocker

Antihypertensive

Therapeutic actions

Inhibits the movement of calcium ions across the membranes of cardiac and vascular smooth muscle cells; greater selectivity for vascular smooth muscle as compared to cardiac muscle; leads to arterial and coronary artery vasodilation and decreased peripheral vascular resistance.

Indications

·        Essential hypertension, alone or in combination with other antihypertensives

Contraindications and cautions

·        Contraindicated with allergy to felodipine or other calcium channel-blockers, sick sinus syndrome, heart block (second or third degree), lactation.

·        Use cautiously with pregnancy, impaired hepatic function.

Available forms

ER tablets—2.5, 5, 10 mg

Dosages

ADULTS

Initially, 5 mg PO daily; dosage may be gradually increased over 10–14 days. Usual dose is 2.5–10 mg PO daily. Doses greater than 10 mg PO daily are associated with an increased risk of peripheral edema.

PEDIATRIC PATIENTS

Safety and efficacy not established.

GERIATRIC PATIENTS OR PATIENTS WITH HEPATIC IMPAIRMENT

Monitor carefully; begin with 2.5 mg daily, and do not exceed 10 mg daily PO.

Pharmacokinetics

Route	Onset	Peak
Oral	2–5 hr	2.5–5 hr

Metabolism: Hepatic; T_1/2: 11–16 hr

Distribution: Crosses placenta; may enter breast milk

Excretion: Urine

Adverse effects

·        CNS: Dizziness, light-headedness, headache, asthenia, fatigue, lethargy

·        CV: Peripheral edema, arrhythmias

·        Dermatologic: Flushing, rash

·        GI: Nausea, abdominal discomfort, reflux, constipation

Interactions

Drug-drug

·        Decreased serum levels with barbiturates, hydantoins, carbamazepine

·        Increased serum levels and toxicity with erythromycin, cimetidine, ranitidine, antifungals

Drug-food

·        Decreased metabolism and increased risk of toxic effects if taken with grapefruit juice; avoid this combination

Nursing considerations

CLINICAL ALERT!

Name confusion has occurred between Plendil (felodipine) and Isordil (isosorbide); use caution.

Assessment

·        History: Allergy to felodipine, impaired hepatic function, sick sinus syndrome, heart block, lactation, pregnancy

·        Physical: Skin lesions, color, edema; P, BP, baseline ECG, peripheral perfusion, auscultation, R, adventitious sounds; liver evaluation, GI normal output; LFTs, urinalysis

Interventions

·        Have patient swallow tablet whole; do not chew or crush.

·        Monitor patient carefully (BP, cardiac rhythm and output) while drug is being adjusted to therapeutic dose.

·        Monitor cardiac rhythm regularly during stabilization of dosage and periodically during long-term therapy.

·        Administer drug without regard to meals.

Teaching points

·        Take this drug with meals if upset stomach occurs; swallow tablet whole, do not cut, crush, or chew. Do not drink grapefruit juice while using this drug.

·        You may experience these side effects: Nausea, vomiting (eat frequent small meals); headache (adjust lighting, noise, and temperature; medication may be ordered if severe).

·        Report irregular heart beat, shortness of breath, swelling of the hands or feet, pronounced dizziness, constipation.

Adverse effects in Italic are most common; those in Bold are life-threatening.