Maximum Dose of Nifedipine
The maximum dose of nifedipine is 180 mg daily for the extended-release (slow-release) formulation, while the immediate-release formulation has a maximum daily dose of 90 mg. 1
Dosing Guidelines for Nifedipine
Extended-Release Nifedipine
- Initial dose typically starts at 30 mg once daily 2
- Can be titrated up to 180 mg daily based on blood pressure response and tolerability 1
- In pediatric patients, the maximum dose is 3 mg/kg per day up to 120 mg/day 1
- Usually administered once or twice daily (QD-BID) 1
Immediate-Release Nifedipine
- Typically dosed at 30-90 mg daily in divided doses 1
- Should not be used for hypertension or angina without concomitant beta-blockade due to risk of adverse cardiovascular events 1
- Immediate-release formulation is associated with rapid drops in blood pressure and reflex tachycardia 1
Clinical Considerations
Formulation Differences
- Sustained-release (GITS - Gastrointestinal Therapeutic System) formulations provide more stable plasma concentrations over 24 hours 3, 4
- Extended-release tablets must be swallowed whole and not crushed or chewed 1
- Sustained-release formulations allow for less frequent administration and better tolerability 4
Efficacy and Dose Response
- More than 50% of hypertensive patients can be controlled on doses of 30-60 mg/day of the extended-release formulation 2
- Higher doses (60 mg/day) show greater efficacy when administered at bedtime compared to morning dosing 3
- Even low-dose nifedipine GITS (20 mg) has demonstrated efficacy in mild to moderate hypertension 5
Safety Considerations
Common Side Effects
- Hypotension, dizziness, flushing, nausea, constipation, and edema 1
- May cause tachycardia, particularly with immediate-release formulations 1
- Peripheral edema incidence increases at higher doses 3
Important Precautions
- Bedtime administration of nifedipine GITS reduces the incidence of edema by 91% compared to morning dosing 3
- Immediate-release nifedipine should be avoided in unstable angina/NSTEMI except with concomitant beta blockade 1
- Contraindicated in children under 1 year of age 1
- Use with caution in pregnancy; calcium channel blockers may cause rapid and excessive blood pressure reduction if given sublingually or intravenously 1
Special Populations
Pediatric Dosing
- Initial dose: 0.25-0.5 mg/kg per day 1
- Maximum dose: 3 mg/kg per day up to 120 mg/day 1
- Used for hypertension management in children, but requires careful monitoring 1
Cardiovascular Disease
- In patients with unstable angina/NSTEMI, nifedipine should only be used when patients are already receiving adequate doses of nitrates and beta blockers 1
- For pulmonary hypertension, high doses (120-240 mg daily) may be required in patients who demonstrate vasoreactivity 1
By understanding the maximum dosing limits and clinical considerations for nifedipine administration, clinicians can optimize therapy while minimizing adverse effects in patients requiring calcium channel blocker treatment.