nifedipine
Brand: Procardia, Adalat CC
Beers Criteria Prototype: amlodipine
Drug Class: calcium channel blocker
Drug Family: antihypertensive
Subclass: dihydropyridine CCB (short-acting IR / extended-release)
Organ Systems: cardiovascularreproductive
Mechanism of Action
Dihydropyridine CCB; IR form causes rapid vasodilation with reflex sympathetic activation; XL form provides smoother profile.
L-type voltage-gated calcium channel
Indications
- hypertension (XL)
- angina (XL/IR)
- vasospastic angina
- preterm labor (tocolysis, off-label)
- hypertensive emergency (IR sublingual — no longer recommended due to unpredictable hypotension)
- Raynaud's phenomenon
Contraindications
- cardiogenic shock
- significant aortic stenosis
- concurrent use of strong CYP3A4 inhibitors (relative)
Adverse Effects
Common
- peripheral edema
- flushing
- headache
- reflex tachycardia (IR)
Serious
- severe hypotension (IR)
- myocardial infarction risk with short-acting form
Pharmacokinetics (ADME)
| Absorption | 45-75% bioavailability; affected by grapefruit |
| Distribution | high protein binding |
| Metabolism | extensive hepatic CYP3A4 |
| Excretion | renal |
| Half-life | 2-5 hours (IR), 7-12 hours (XL) |
| Onset | 20 min (IR/sublingual), hours (XL) |
| Peak | 0.5-2 hours (IR) |
| Duration | 6-8 hours (IR), 24 hours (XL) |
| Protein Binding | 92-98% |
| Vd | 0.77 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| grapefruit juice | inhibits CYP3A4 in GI wall, increases nifedipine levels | major |
| CYP3A4 inhibitors | increased nifedipine levels | major |
Nursing Considerations
- AVOID sublingual IR for hypertensive emergency (unpredictable BP drop; increased MI risk)
- Instruct patients to avoid grapefruit juice
- XL formulation preferred for hypertension
- Monitor for reflex tachycardia with IR form
- Tocolysis in preterm labor: monitor maternal and fetal HR
Clinical Pearls
- IR sublingual use for hypertensive urgency is CONTRAINDICATED — caused fatal MIs in trials
- Grapefruit interaction: classic CYP3A4 inhibition in GI wall
- XL formulation created to overcome reflex tachycardia of IR form
Safety Profile
Pregnancy avoid
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.