What is the appropriate dosing for Nifedipine (Calcium Channel Blocker)?

From the Guidelines

Nifedipine should be dosed at 30 to 90 mg daily orally for immediate release and 30 to 180 mg orally for slow release, with caution and consideration of concomitant beta blockade due to increased adverse potential without it 1.

Nifedipine Dosing Considerations

When considering nifedipine dosing, it's crucial to differentiate between immediate-release and slow-release formulations.

• Immediate-release nifedipine is typically dosed at 30 to 90 mg daily orally, while slow-release formulations are dosed at 30 to 180 mg orally.
• The choice between these formulations depends on the clinical context, including the presence of unstable angina or non-ST-elevation myocardial infarction (UA/NSTEMI), and the need for concomitant beta blockade.

Clinical Context and Side Effects

In the context of UA/NSTEMI, nifedipine should be used with caution and ideally with concomitant beta blockade to mitigate the risk of adverse events 1.

• Common side effects of nifedipine include hypotension, dizziness, flushing, nausea, constipation, and edema.
• It's essential to monitor patients for these side effects and adjust the dose accordingly to minimize risks while achieving therapeutic benefits.

Special Considerations

For patients with specific conditions, such as hepatic impairment or elderly patients, lower initial doses of nifedipine may be necessary to avoid adverse effects 1.

• Additionally, it's critical to avoid abrupt discontinuation of nifedipine, as this can worsen angina symptoms.
• Extended-release tablets should be taken whole without crushing or chewing to maintain their controlled-release mechanism and ensure consistent therapeutic effects.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Dosage should be adjusted according to each patient's needs. It is recommended that nifedipine extended-release tablets, USP be administered orally once daily on an empty stomach. The nifedipine extended-release tablet, USP is an extended release dosage form and tablets should be swallowed whole, not bitten or divided In general, titration should proceed over a 7-14 day period starting with 30 mg once daily. Upward titration should be based on therapeutic efficacy and safety. The usual maintenance dose is 30 mg to 60 mg once daily. Titration to doses above 90 mg daily is not recommended

• Initial Dose: 30 mg once daily
• Maintenance Dose: 30 mg to 60 mg once daily
• Maximum Dose: Not to exceed 90 mg daily 2

From the Research

Nifedipine Dosing

• Nifedipine is a dihydropyridine calcium channel antagonist with predominantly vasodilatory activity 3.
• The exact mechanism of action of nifedipine in various disorders has not been defined, but its potent peripheral and coronary arterial dilator properties are of particular importance 4.
• Sustained release formulations of nifedipine have been shown to be effective in the treatment of mild to moderate hypertension and both stable and variant angina pectoris 4.
• The extended-release formulation of nifedipine given once daily provides a relatively constant concentration profile and has proved to be effective in reducing blood pressure values 5.

Administration and Dosage

• A major goal of sustained release therapy is to permit reductions in the frequency of nifedipine administration, preferably to once daily, and thus improve patient compliance 4.
• Two new once-daily formulations--the nifedipine gastrointestinal therapeutic system (GITS) and a fixed combination capsule comprising sustained release nifedipine 20 mg and atenolol 50 mg--have exhibited marked antihypertensive efficacy 4.
• Modified-release formulations of nifedipine that produce a gradual increase in plasma nifedipine concentration, which is then sustained over a 24-hour period, are preferred 3.

Adverse Effects and Tolerability

• Adverse effects of nifedipine seem to be dose related, are mainly associated with the drug's potent vasodilatory action, and include headache, flushing, and dizziness 4.
• Generally, these effects are mild to moderate in severity and transient, usually diminishing with continued treatment 4.
• Sustained release nifedipine formulations are generally better tolerated than their conventionally formulated counterparts, particularly with regard to reflex tachycardia 4.