Pharm

Nifedipine

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Nifedipine, Procardia, Adalat, Afeditab

  • See Also
  1. Dihydropyridine Calcium Channel Blocker
  2. Calcium Channel Blocker
  3. Calcium Channel Blocker Overdose
  4. Diltiazem
  5. Verapamil
  6. Mibefradil
  • Indications
  1. Hypertension
    1. Not recommended as first-line Hypertension Management or for monotherapy
  2. Preterm Labor
  • Contraindications
  1. Congestive Heart Failure
  2. Aortic Stenosis
  3. Avoid in Diabetes Mellitus (may increase Proteinuria)
  4. Concomitant use of Magnesium Sulfate
    1. Theoretically deactivates Calcium Gluconate antidote
  • Precautions
  1. General
    1. Take on an empty Stomach
  2. Extended Release Tablets
    1. Write for generic Nifedipine ER to allow pharmacist to substitute between multiple similar ER preparations
    2. (2016) Presc Lett 23(7): 39-40
  3. Immediate release tablets
    1. Do not use for Hypertension, Hypertensive Emergency or STEMI (risk of worsening coronary ischemia)
    2. Do not chew, swallow or take sublingually
  • Mechanism
  1. See Dihydropyridine Calcium Channel Blocker
  2. Prototypes for Dihydropyridine Calcium Channel Blockers: Amlodipine, Nimodipine
  3. Potent peripheral vasodilation
  4. Minimal SA Node or AV Node depression
  5. No Coronary Artery dilation
  1. Nifedipine Extended Release or ER (Procardia XL)
    1. Start Nifedipine ER 30 to 60 mg orally daily
    2. Maximum 120 mg/day
  2. Nifedipine Immediate Release (rare use)
    1. Do not use for Hypertension, Hypertensive Emergency or STEMI (risk of worsening coronary ischemia)
    2. Start 10 mg orally three times daily
    3. Target: 10 to 20 mg orally three times daily
    4. Maximum 120 mg/day
  1. See Tocolytic
  2. Load: Nifedipine 10 mg sublingual every 20 minutes for 3 doses as needed (up to a cummulative 40 mg in first hour)
  3. Maintenance: Nifedipine Immediate Release 10 to 20 mg orally every 4 to 8 hours
    1. Alternative: Nifedipine ER 60 to 160 mg once daily
  4. Monitoring: When used in Preterm Labor
    1. Blood Pressure
    2. Edema
    3. Serial Fetal Ultrasounds
  1. See Medical Expulsive Therapy
  2. Nifedipine ER 30 mg orally daily until stone passage (up to 30 days)
  1. Start 0.25 to 0.5 mg/kg/dose every 4 to 6 hours as needed
  2. Maximum: 3 mg/kg/day or 10 mg/dose
  • Adverse Effects
  1. See Calcium Channel Blockers
  2. Angina
    1. Avoid short acting agents for Hypertension or STEMI (increased coronary risk)
  3. Gastrointestinal obstruction (extended release tablet)
  4. Reflex Tachycardia
  5. Transient Hypotension
  6. Peripheral Edema
  7. Pulmonary Edema
  8. Dizziness
  9. Nausea
  • Safety
  1. Pregnancy Category C
    1. Risk of Intrauterine Growth Retardation
  2. Avoid in Lactation
  • Metabolism
  1. Rapid and near complete absorption of sublingual (SL) route
  2. Highly Protein bound (98%)
  3. CYP3A4 metabolism to inactive metabolites
  4. Immediate Release Half Life: 3 hours
  5. Reduce dosing in hepatic dysfunction
  • Drug Interactions
  1. Agents that lower Nifedipine levels
    1. Carbamazepine
    2. Phenobarbital
    3. Phenytoin
    4. Rifampin
    5. St John's Wort
  2. Agents that increase Nifedipine levels
    1. Clarithromycin
    2. Erythromycin
    3. Fluconazole
    4. Fluoxetine
    5. Protease Inhibitors
    6. Ketoconazole
    7. Itraconazole
    8. Grapefruit Juice
  3. Agents whose levels are increased by Nifedipine
    1. Tacrolimus
    2. Anticoagulants
  4. Perioperative Beta Blocker and Fentanyl
    1. Severe Hypotension risk
    2. Discontinue Nifedipine 36 hours before surgery
  • Resources
  1. Nifedipine ER (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d1a78ff2-7672-3e69-00ef-63d203c80484
  • References
  1. (2022) Presc Lett, Resource #381108, Comparison of Calcium Channel Blockers
  2. (2020) Med Lett Drugs Ther 62(1598): 73-80
  3. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 70-1
  4. Hamilton (2020) Tarascon Pocket Pharmacopoeia