From the Guidelines
Nifedipine 30 mg can be given twice daily, but only with the extended-release formulation and with caution, as immediate-release nifedipine is not recommended for UA/NSTEMI except with concomitant beta blockade 1. The standard dosing for nifedipine extended-release for conditions like hypertension or angina is typically 30-60 mg once daily, but divided twice-daily dosing of 30 mg is sometimes prescribed to improve blood pressure control throughout the day or to reduce side effects. It's essential to note that only extended-release formulations should be used twice daily; immediate-release nifedipine requires more frequent dosing (usually three times daily) 1. Patients should swallow the extended-release tablets whole without crushing or chewing them, as this would disrupt the controlled-release mechanism and potentially cause dangerous blood pressure fluctuations. Common side effects include headache, flushing, dizziness, and ankle swelling. Nifedipine works by blocking calcium channels in blood vessels, causing them to relax and widen, which reduces blood pressure and improves blood flow to the heart. Some key points to consider when prescribing nifedipine include:
- The choice of formulation (extended-release vs. immediate-release) and dosing frequency
- The potential for side effects, such as hypotension, dizziness, and edema
- The importance of concomitant beta blockade when using immediate-release nifedipine in UA/NSTEMI patients
- The need for careful monitoring of patients with certain comorbidities, such as severe LV dysfunction or pulmonary edema. In general, the use of nifedipine should be individualized and guided by the specific clinical context and patient characteristics, with careful consideration of the potential benefits and risks 1.
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 usual maintenance dose is 30 mg to 60 mg once daily.
The FDA recommends administering nifedipine extended-release tablets once daily. Giving nifedipine 30 mg twice a day is not recommended as it exceeds the recommended daily dose frequency and may increase the risk of adverse effects. 2
From the Research
Nifedipine Dosage
- The dosage of nifedipine can vary depending on the specific formulation and the condition being treated 3, 4.
- For the treatment of hypertension, a common dosage is 30 mg once daily, with the option to increase to 60 mg once daily if necessary 3.
- However, the question asks about taking 30 mg twice a day, which is not a standard dosage regimen mentioned in the provided studies.
- It is essential to note that nifedipine should be taken as directed by a healthcare professional, and any changes to the dosage should be made under their guidance.
Efficacy and Safety
- Nifedipine has been shown to be effective in reducing blood pressure and preventing cardiovascular events 5, 3, 4.
- The drug is generally well-tolerated, with common side effects including edema, headache, and flushing 6, 7.
- However, high doses of nifedipine can cause more severe side effects, and caution is required when using the drug in certain patient populations, such as those with cardiac dysrhythmias or myocardial failure 6, 7.
Formulations
- Nifedipine is available in various formulations, including immediate-release and extended-release tablets 5, 3.
- The extended-release formulation is designed to provide a relatively constant concentration profile and can be taken once daily 4.
- The choice of formulation and dosage regimen should be based on individual patient needs and medical history.