Recommended Dosage of Nifedipine for Hypertension and Angina
For hypertension and angina management, the recommended dosage of nifedipine is 30-90 mg daily of extended-release formulation, with extended-release formulations strongly preferred over immediate-release due to better safety profile. 1
Formulation Options and Dosing
Extended-Release Nifedipine (Preferred)
- For hypertension: 30-180 mg once daily of extended-release formulation 1
- For angina: 30-180 mg once daily of extended-release formulation 1
- Extended-release formulations maintain therapeutic blood levels for approximately 24 hours, providing more consistent plasma concentrations 1, 2
Immediate-Release Nifedipine (Use with Caution)
- For angina: 30-90 mg daily divided into multiple doses 1
- Immediate-release nifedipine should not be used without concomitant beta-blockade due to risk of adverse cardiovascular events 1, 3
- Avoid use in acute coronary syndromes due to risk of reflex sympathetic activation 3
Dosing Considerations for Special Populations
- In elderly patients (>60 years), plasma concentration may be 70% greater than in younger patients, suggesting lower initial dosing may be appropriate 2
- For patients with hepatic impairment, nifedipine has a longer elimination half-life and higher bioavailability, requiring dose adjustment 2
- For pediatric pulmonary hypertension, starting dose is 0.1-0.2 mg/kg orally 3 times daily, with a dose range of 2-3 mg/kg/day (maximum 180 mg/day) 1
Clinical Efficacy
- Nifedipine produces dose-related decreases in systolic and diastolic blood pressure 2
- For resistant hypertension, dihydropyridine calcium channel blockers like nifedipine extended-release are among the most studied agents 1
- When combined with beta-blockers like atenolol, nifedipine can achieve anti-hypertensive effects at lower doses than when used as monotherapy 4
Monitoring and Adverse Effects
- Common side effects include hypotension, dizziness, flushing, headache, nausea, constipation, and peripheral edema 1, 2
- Side effects are generally dose-related and associated with vasodilatory action 5
- Monitor for reflex tachycardia, particularly with immediate-release formulations 5
Important Considerations and Cautions
- Avoid grapefruit juice while taking nifedipine as it can increase AUC and Cmax up to 2-fold 2
- Nifedipine is metabolized via cytochrome P450 3A4 system; drugs that inhibit or induce this enzyme may alter nifedipine clearance 2
- For patients unable to swallow tablets, consider alternative calcium channel blockers in liquid formulations rather than immediate-release nifedipine liquid 1
- In a study of patients with controlled hypertension on nifedipine GITS 30 mg, 95.7% maintained blood pressure control when switched to 20 mg daily, suggesting that lower doses may be effective for maintenance therapy 6
Comparative Efficacy
- Long-acting formulations of nifedipine may have slightly greater antihypertensive actions than amlodipine but are associated with more edema 1
- For patients with vasospastic angina, amlodipine's once-daily dosing may offer better compliance compared to multiple daily dosing of immediate-release nifedipine 3