Felodipine
Mechanism :
Inhibits calcium ions from entering the “slow channels” or select voltage-sensitive areas of vascular smooth muscle and myocardium during depolarization, producing a relaxation of coronary vascular smooth muscle and coronary vasodilation.
Indication :
- Management of hypertension (off-label in children)
Contraindications :
Hypersensitivity to felodipine or other dihydropyridines; women of childbearing potential, in pregnancy, and during lactation.
Dosing :
Children ≥6 years and Adolescents (off-label use):
Oral:
Initial: 2.5 mg once daily; may increase as needed at no less than 2-week intervals to a maximum of 10 mg once daily
Adverse Effect :
Peripheral edema, headache, flushing, tachycardia.
Interaction :
Alpha1-Blockers: May enhance the hypotensive effect of Calcium Channel Blockers.
Calcium Channel Blockers (Nondihydropyridine): Calcium Channel Blockers (Dihydropyridine) may enhance the hypotensive effect of Calcium Channel Blockers (Nondihydropyridine).
CYP3A4 Inducers: May increase the metabolism of CYP3A4 Substrates.
CYP3A4 Inhibitors: May decrease the metabolism of CYP3A4 Substrates.
Fosphenytoin: Calcium Channel Blockers may increase the serum concentration of Fosphenytoin.
Hypotension-Associated Agents: Blood Pressure Lowering Agents may enhance the hypotensive effect of Hypotension-Associated Agents.
Ketoconazole (Systemic): May increase the serum concentration of Felodipine.
Phenytoin: Calcium Channel Blockers may increase the serum concentration of Phenytoin.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in normal renal function |
| HD | Not dialysed. Dose as in normal renal function |
| HDF/High flux | Not dialysed. Dose as in normal renal function |
| CAV/VVHD | Not dialysed. Dose as in normal renal function |
Hepatic Dose :
Patients with impaired hepatic function may have elevated plasma concentrations of felodipine and may respond to lower doses.
For adults: Reduce initial dosage to 2.5 mg PO once daily in hepatic impairment. Dosage may be increased cautiously based on clinical response. Maintenance dose can be adjusted to 2.5 to 10 mg orally once a day depending upon clinical benefits and drug toxicity.
For Pediatrics: No specific guidelines for dosing in pediatric population with hepatic impairment are given, however on the basis of adult drug studies with hepatic impairment and pharmacokinetics of the drug, dose adjustments in pediatric population with hepatic impairment is recommended