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Mibefradil

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Mibefradil, T-Type Calcium Channel Blocker

  • See Also
  1. Calcium Channel Blocker
  2. Calcium Channel Blocker Overdose
  3. Dihydropyridine Calcium Channel Blocker (e.g. Amlodipine, Nifedipine)
  4. Diltiazem
  5. Verapamil
  • Indications
  1. Chronic Stable Angina
  2. Hypertension
  • Contraindications
  1. Sick Sinus Syndrome
  2. AV Block without a Pacemaker
  • Mechanism
  1. Blocks Calcium influx at 2 types of Calcium channels
    1. L-type (long-acting) channels
      1. Blocked by standard Calcium Channel Blockers
    2. T-type (transient) channels
      1. Blocked uniquely by Mibefradil
      2. Activated at lower voltages
      3. Present in:
        1. Vascular Smooth Muscle
        2. Myocardial conduction system
      4. Absent in
        1. Ventricular Myocardium
  2. Effect of Mibefradil
    1. Produces coronary and peripheral vasodilatation
    2. Does not result in reflex Tachycardia
  • Dosing
  1. 50 mg orally daily (up to 100 mg orally daily)
  • Efficacy
  1. Antihypertensive
    1. More effective then Diltiazem
    2. As effective as Amlodipine and Nifedipine
    3. Synergistic effect with ACE Inhibitors
  2. Anti-Anginal
    1. Delays onset of ischemia during Exercise
    2. Increases Exercise tolerance
  • Drug Interactions
  1. Fatal Arrhythmia risk with
    1. Terfenadine
    2. Astemizole
    3. Cisapride
  2. Increases levels of
    1. Tricyclic Antidepressant
    2. Cyclosporine
  • Adverse Effects
  1. See Calcium Channel Blocker
  2. Dizziness
  3. Fatigue
  4. Light Headedness
  5. Peripheral Edema LESS common than others in class
  • References
  1. (1997) Med Lett Drugs Ther 39:103-5 [PubMed]