Nifedipine Extended Release Equivalent Dosing
For a patient taking immediate-release nifedipine 10mg three times daily (30mg total daily dose), the equivalent extended-release dosage is 30mg once daily. 1, 2
Conversion Rationale
When converting from immediate-release nifedipine to extended-release formulations, the following factors should be considered:
- The total daily dose of immediate-release nifedipine (10mg × 3 = 30mg daily) directly corresponds to the starting dose of extended-release nifedipine 1, 2
- According to the FDA-approved labeling, nifedipine extended-release tablets should be administered once daily on an empty stomach 2
- Extended-release tablets must be swallowed whole, not bitten or divided 2
Administration Guidelines
- Starting dose: 30mg once daily
- Titration: If needed, dose can be increased after 7-14 days based on blood pressure response and tolerability 2
- Maintenance dose: 30-60mg once daily is the usual maintenance dose
- Maximum dose: Doses above 90mg daily are not recommended 2
Important Clinical Considerations
- Extended-release formulations provide more consistent plasma levels throughout the 24-hour period, reducing the risk of adverse effects associated with peak concentrations 3
- Bedtime administration of nifedipine extended-release has been shown to reduce the incidence of edema by 91% compared to morning dosing 3
- Nifedipine extended-release should be taken on an empty stomach to ensure proper absorption 2
Potential Adverse Effects
- Common side effects include hypotension, dizziness, flushing, nausea, constipation, and peripheral edema 1
- Immediate-release nifedipine should be avoided in patients with unstable angina/NSTEMI except with concomitant beta blockade due to increased adverse potential 1
Cautions and Contraindications
- Avoid rapid-release, short-acting dihydropyridines (like immediate-release nifedipine) without concomitant beta blockade due to increased risk of adverse events 1
- Use with caution in patients with heart failure or severe left ventricular dysfunction 1
- Co-administration with grapefruit juice should be avoided 2
Monitoring Recommendations
- Monitor blood pressure and heart rate 2-4 weeks after switching between different extended-release formulations of nifedipine 4
- Assess for peripheral edema, especially with higher doses
- Monitor for symptomatic hypotension, particularly when initiating therapy
By maintaining the same total daily dose when converting from immediate-release to extended-release formulations, you can provide similar efficacy with improved adherence and potentially fewer adverse effects due to the more stable plasma concentration profile.