From the Guidelines
Nifedipine should be dosed at night, with extended-release formulations typically ranging from 30-90 mg taken once daily, to help control blood pressure and reduce the risk of cardiovascular events. The evening dosing of nifedipine takes advantage of the medication's pharmacokinetics, allowing peak effects to coincide with the early morning surge in blood pressure that occurs naturally due to circadian rhythms 1. This timing may help reduce the risk of cardiovascular events like heart attacks and strokes that tend to occur more frequently in the morning hours. Patients should take nifedipine consistently at the same time each evening, with or without food, and should swallow extended-release tablets whole without crushing or chewing them. Side effects may include headache, flushing, dizziness, and ankle swelling, which sometimes improve with continued use 1. If experiencing severe side effects, patients should contact their healthcare provider rather than discontinuing the medication abruptly. Some key points to consider when dosing nifedipine include:
- The usual dose for extended-release nifedipine is 30-180 mg orally once daily 1
- Immediate-release nifedipine is not recommended for UA/NSTEMI except with concomitant beta blockade 1
- Nifedipine can cause hypotension, dizziness, flushing, nausea, constipation, and edema as side effects 1
From the Research
Nifedipine Night Time Dosing
- Nifedipine is a calcium channel blocker used to treat hypertension and angina pectoris, and its formulation has undergone modifications to improve its pharmacokinetic profile and administration regimen 2.
- The nifedipine gastrointestinal therapeutic system (GITS) is a controlled-release formulation for once-a-day dosing, and its efficacy and safety have been evaluated in several studies 3, 4, 5.
- A study published in 1994 found that morning and evening administration of nifedipine GITS had a sustained antihypertensive effect throughout the whole day without affecting the circadian rhythm, and there was no significant difference between morning and evening administration 3.
- Another study published in 2007 found that bedtime administration of nifedipine GITS reduced the incidence of edema as an adverse event by 91% and the total number of all adverse events by 74% compared to morning dosing 4.
- A study published in 2008 found that bedtime dosing of nifedipine GITS was associated with a significant reduction in nighttime blood pressure and a reduction in the incidence of edema compared to morning dosing 5.
- A more recent study published in 2021 found that nighttime dosing of nifedipine GITS or amlodipine had similar effects on nocturnal blood pressure reduction, dipping rhythm restoration, and arterial elasticity improvement in non-dipper hypertensive patients, and these effects were comparable with morning dosing 6.
Key Findings
- Nifedipine GITS can be administered at any time of day without affecting its antihypertensive efficacy 3.
- Bedtime administration of nifedipine GITS may have a better safety profile compared to morning dosing, with reduced incidence of edema and other adverse events 4, 5.
- The choice of dosing time may depend on individual patient characteristics and preferences, and further studies are needed to determine the optimal dosing time for nifedipine GITS 6.