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Sedating Antihistamine

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Sedating Antihistamine, First Generation Antihistamine, Antihistamine, Chlorpheniramine, Bromopheniramine, Cyproheptadine, Hydroxyzine, Periactin, Atarax, Vistaril

  • Mechanism
  1. First Generation Antihistamine
  • Adverse Effects
  1. See Anticholinergic Toxicity
  2. Sedation or Paradoxic excitability
  3. Worsens Benign Prostatic Hyperplasia
  4. Worsens Glaucoma
  5. Dizziness
  6. Respiratory depression
  7. Tachycardia
  8. Seizures
  9. QT Prolongation (and Torsades de Pointes)
    1. Especially with Hydroxyzine
  10. Anticholinergic Symptoms
    1. Hallucinations
    2. Blurred Vision
    3. Agitation
  • Indications
  1. Allergic Rhinitis
  2. Antiemetic
  3. Anaphylaxis
  4. Acute Urticaria
  5. Chronic Urticaria
  6. Anti-pruritic
    1. Suppresses itching, and reduces lesions
    2. Does not completely eradicate
    3. Hydroxyzine (Atarax) is most potent Antihistamine for Pruritus
  • Preparations
  • Antihistamine
  1. See Diphenhydramine (Benadryl)
  2. Chlorpheniramine (Chlor-Trimeton)
    1. Dose: 4 mg orally every 4 to 6 hours as needed
  3. Clemastine (Tavist)
    1. Dose: 1.34 mg orally twice daily as needed
  4. Cyproheptadine (Periactin)
    1. Dose: 4 mg orally three times daily as needed
  5. Hydroxyzine (Atarax, Vistaril)
    1. Dose: 0.5 mg/kg up to 25-50 mg orally or intramuscular every 4-6 hours as needed