Felodipine

ADMINISTRATION ROUTES:

PO

ALTERNATIVE NAMES:

Felo ER, Plendil ER

ICU INDICATIONS:

1. Hypertension
2. Afterload reduction
3. Angina (rarely used for this indication in the ICU)

PRESENTATION AND ADMINISTRATION:

PO:

Felo ER 5mg (light pink) and Felo ER 10 mg (reddish-brown)

Plendil ER 2.5mg (yellow), Plendil ER 5mg (pink), Plendil ER 10 mg (red-brown)

DOSAGE:

Hypertension & afterload reduction:

5 mg OD; increase to max 10 mg daily

Note: tablets must not be crushed; use an alternative if NG administration is necessary

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

Dose as in normal renal function

DOSAGE IN PAEDIATRICS:

0.1-0.5 mg/kg OD

CLINICAL PHARMACOLOGY:

Felodipine is a dihydropyridine calcium channel blocker. Felodipine is a peripheral arterial vasodilator that acts directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure. It does not cause significant negative inotropy.

CONTRAINDICATIONS:

1. Known hypersensitivity to felodipine

WARNINGS:

Increased Angina and/or Myocardial Infarction

Rarely, patients, particularly those with severe obstructive coronary artery disease, have developed documented increased frequency, duration and/or severity of angina or acute myocardial infarction on starting calcium channel blocker therapy or at the time of dosage increase. The mechanism of this effect has not been elucidated.

PRECAUTIONS:

General:

Caution should be exercised when administering felodipine as with any other peripheral vasodilator particularly in patients with severe aortic stenosis.

Patients with impaired liver function may have elevated plasma concentrations of felodipine and may respond to lower doses of felodipine; therefore, a starting dose of 2.5 mg once a day is recommended.

Laboratory Tests:

No tests in addition to routine ICU tests are required

Drug/Laboratory Test Interactions:

None known

IMPORTANT DRUG INTERACTIONS IN ICU:

Felodipine is metabolised by CYP3A4. Co-administration of CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, erythromycin, grapefruit juice, cimetidine) with felodipine may lead to several-fold increases in the plasma levels of felodipine, either due to an increase in bioavailability or due to a decrease in metabolism.

ADVERSE REACTIONS:

Cardiovascular System:

Hypotension, syncope, angina pectoris, arrhythmia, tachycardia, premature beats

Digestive System:

Abdominal pain, diarrhoea, vomiting, dry mouth, flatulence, acid regurgitation, increased ALT

Musculoskeletal System:

Arthralgia, back pain, leg pain, foot pain, muscle cramps, myalgia, arm pain, knee pain, hip pain

Respiratory System:

Dyspnoea, pharyngitis, bronchitis, influenza, sinusitis, epistaxis, respiratory infection.

Skin:

Angioedema, contusion, erythema, urticaria, leukocytoclastic vasculitis