Nifedipine
General
- Type: Calcium Channel Blocker, Dihydropyridine
- Dosage Forms: 10,20; 30,60,90 ER PO
- Common Trade Names: Procardia, Nifediac, Nifedical, Adalat, Afeditab
Adult Dosing
Preterm labor/Tocolysis
- 20mg x1, additional 20mg dose in 90min if ctx persist, followed by 20mg q3-8 hrs PRN ctx
Hypertension, Angina, Pulmonary hypertension
- 30-60mg ER PO daily
Pediatric Dosing
Hypertensive emergency
- 0.25-0.5mg/kg PO q4-6h
- Max: 10mg/dose up to 1-2mg/kg/day
Hypertrophic cardiomyopathy
- 0.6-0.9mg/kg/day PO divided tid-QID
Special Populations
- Pregnancy Rating: C
- Lactation: Probably safe
- Renal Dosing
- Adult: no adjustment
- Pediatric: no adjustment
- Hepatic Dosing
- Adult: not defined
- Pediatric: not defined
Contraindications
- Allergy to class/drug
- galactose intolerance (lactose-containing forms)
- hypertensive crisis (IR form)
- hypertension (IR form)
- caution if CHF
- caution if aortic stenosis
- caution if hypotension
- caution if renal impairment
- caution if hepatic impairment
- caution if anesthesia or surgery
- caution if concurrent or recent β-blocker use
- caution if GI stricture, severe (XL form)
- caution if GI hypomotility disorder (XL form)
- caution in elderly patients
Adverse Reactions
Serious
- CHF
- pulmonary edema
- MI
- arrhythmias
- hypotension, severe
- cholestasis
- allergic hepatitis
- angioedema
- anaphylaxis
- Stevens-Johnson syndrome
- exfoliative dermatitis
- toxic epidermal necrolysis
- exanthematous pustulosis, acute generalized
- GI obstruction (XL form)
- GI ulcer (XL form)
Common
- peripheral edema
- headache
- dizziness
- flushing
- fatigue/weakness
- nausea
- constipation
- muscle cramps
- nervousness
- palpitations
- dyspnea
- nasal congestion
- hypotension, transient
- eczematous eruptions (chronic use, elderly patients)
Pharmacology
- Half-life: 2h, 7h (ER)
- Metabolism: liver, CYP450: 3A4 substrate
- Excretion: urine 60-80% (<0.1% unchanged), bile/feces 20%
- Mechanism of Action: inhibits calcium ion influx into vascular smooth muscle and myocardium