PROCARDIA
Clinical safety rating
cautionComprehensive clinical and safety monograph for PROCARDIA (PROCARDIA).
Dihydropyridine calcium channel blocker that inhibits the influx of calcium ions through L-type calcium channels in vascular smooth muscle and cardiac muscle, leading to vasodilation and reduced myocardial contractility.
| Metabolism | Primarily metabolized by cytochrome P450 3A4 (CYP3A4) to inactive metabolites. |
| Excretion | Renal (70-80% as metabolites, <1% unchanged); fecal (15-20% via bile); 0% unchanged in urine. |
| Half-life | 2-5 hours in healthy adults; up to 6-10 hours in cirrhotic patients or elderly; clinical context: requires extended-release formulations for once-daily dosing. |
| Protein binding | 92-98% bound to serum albumin. |
| Volume of Distribution | 1.0-1.5 L/kg; large distribution suggests extensive tissue penetration. |
| Bioavailability | Immediate-release: 40-60% (extensive first-pass metabolism); sustained-release: 80-90% relative to immediate-release formulation. |
| Onset of Action | Immediate-release capsule: 20 min orally; sublingual: 2-3 min; sustained-release: 30-60 min. |
| Duration of Action | Immediate-release: 4-6 hours; sustained-release: 12-24 hours; clinical note: reflex tachycardia may persist beyond antihypertensive effect. |
| Molecular Weight | 346.34 |
Initial dose: 10 mg orally 3 times daily; maintenance: 10-30 mg 3-4 times daily; maximum 180 mg/day. Extended-release (XL): 30-60 mg once daily; titrate up to 120 mg/day.
| Dosage form | CAPSULE |
| Renal impairment | No specific dose adjustment required; use caution in severe renal impairment (GFR <30 mL/min). |
| Liver impairment | Child-Pugh Class A: reduce dose by 50%; Class B or C: contraindicated or use with extreme caution, reduce dose by 60-75%. |
| Pediatric use | Not FDA-approved for pediatric use; off-label: 0.25-0.5 mg/kg/dose orally every 6-8 hours, maximum 3 mg/kg/day. |
| Geriatric use | Initiate at lower doses (e.g., 10 mg immediate-release 3 times daily or 30 mg XL once daily); titrate slowly; monitor for hypotension and edema. |
| 1st trimester | Category C: Animal studies show fetal abnormalities; no adequate human studies. Use only if potential benefit justifies risk. |
| 2nd trimester | Category C: May cause fetal hypoxia due to maternal hypotension; avoid chronic use. Short-term use with caution. |
| 3rd trimester | Category C: Risk of fetal distress, premature labor, and maternal hypotension. Avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for PROCARDIA (PROCARDIA).
| Placental transfer | Crosses placenta; umbilical cord plasma concentrations are 70-90% of maternal levels. |
| Breastfeeding | Nifedipine is excreted into breast milk in low concentrations (milk:plasma ratio ~0.3-0.8). No adverse effects reported in infants. Use with caution in preterm or low-birth-weight infants due to immature hepatic metabolism. |
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | First trimester: No increased risk of major malformations in human studies; however, in animal studies, nifedipine caused embryotoxicity and teratogenicity at high doses. Second and third trimesters: Associated with reduced uteroplacental blood flow, fetal hypoxia, and low birth weight. Tocolysis use may cause maternal hypotension and fetal distress. Overall, FDA Category C. |
| Fetal Monitoring | Maternal: blood pressure, heart rate, signs of hypotension. Fetal: ultrasound for growth and amniotic fluid volume during chronic use; fetal heart rate monitoring during tocolysis. Monitor for maternal pulmonary edema if used as tocolytic. |
| Fertility Effects | No significant effects on fertility reported in human studies. Animal studies showed no impairment of fertility at therapeutic doses. |
■ FDA Black Box Warning
No FDA-issued black box warning.
| Serious Effects |
Hypersensitivity to nifedipine or any dihydropyridineCardiogenic shockUnstable angina (except Prinzmetal's variant)Within 4 weeks of myocardial infarctionConcurrent use with rifampin
| Precautions | May cause severe hypotension especially with concomitant beta-blockers, Peripheral edema, Gingival hyperplasia, Hepatic impairment may require dose adjustment, Avoid abrupt discontinuation (may worsen angina), Increased risk of myocardial infarction in patients with coronary artery disease |
| Food/Dietary | Grapefruit juice and grapefruit increase the AUC and Cmax of nifedipine by approximately 2-fold due to CYP3A4 inhibition; avoid concurrent consumption. Alcohol may exacerbate hypotension and vasodilatory effects. High-fat meals can delay absorption of extended-release tablets but do not significantly alter overall bioavailability. |
| Clinical Pearls | Nifedipine (Procardia) is a dihydropyridine calcium channel blocker with potent vasodilatory effects. Avoid sublingual administration of short-acting capsules due to risk of profound hypotension, myocardial ischemia, and stroke. Use only extended-release formulations for chronic hypertension or stable angina. May cause peripheral edema; differentiate from heart failure. Gingival hyperplasia can occur with chronic use. Contraindicated in patients with a history of hypersensitivity to dihydropyridines, cardiogenic shock, significant aortic stenosis, or within 4 weeks of myocardial infarction. |
| Patient Advice | Swallow extended-release tablets whole; do not crush, chew, or split. · Avoid grapefruit juice and grapefruit products as they increase nifedipine levels and risk of toxicity. · Report persistent swelling of ankles/feet, severe headaches, dizziness, or palpitations to your healthcare provider. · Rise slowly from sitting or lying positions to minimize orthostatic hypotension. · Practice good oral hygiene and regular dental check-ups to reduce risk of gum overgrowth. · Do not stop taking this medication abruptly; taper under medical supervision to avoid rebound angina. |
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