Nifedipine

From WikEM
Jump to: navigation, search

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

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

See Also

References