Pharm

Interferon Beta-1A

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Interferon Beta-1A, Peginterferon Beta-1A, Avonex, Rebif, Plegridy, Interferon Beta, Interferon Beta-1

  • Indications
  1. Multiple Sclerosis - Relapsing Forms
    1. Interferon has the longest use in MS than any of the other immunomodulators
  • Mechanism
  1. Interferon is an endogenous Cytokine (integral to inflammatory and immune responses)
    1. Released from Lymphocytes, Dendritic Cells, Macrophages, fibroblasts, Natural Killer Cells and T Cells
  2. Interferon is subdivided into three main types (alpha, beta, gamma)
    1. Alpha and beta Interferon both have Antiviral activity
    2. Synthesized alpha Interferon has primarily been used for Viral Hepatitis B and C infection, as well as cancer
    3. Synthesized beta Interferon has primarily been used to treat Multiple Sclerosis
  3. Interferon Beta is a type 1 Interferon, a Cytokine produced by fibroblasts
    1. Released in response to viral contact or DS-DNA
    2. Has Antiviral, antiproliferative and immunomodulator activity
  • Medications
  1. Interferon Beta-1A
    1. Avonex 30 mcg vials or prefilled syringes
    2. Rebif Titration Kits, and 22 and 44 mcg prefilled syringes and autoinjectors
  2. Peginterferon Beta-1A
    1. Plegridy Starter Pack and 125 mcg pens and prefilled syringes
  • Dosing
  1. Avonex
    1. Target Dose: 30 mcg IM once weekly
    2. Start: 7.5 mcg IM weekly and increase dose by 7.5 mcg each week until at 30 mcg dose
      1. Titration allows for lower risk of flu-like symptoms
  2. Rebif
    1. Choose between 2 target doses
    2. Target 22 mcg SC three times weekly (same days each week, each dose 48 hours apart)
      1. Start 4.4 mcg SQ three times weekly for 2 weeks
      2. Next 11 mcg SQ three times weekly for 2 weeks,
      3. Next 22 mcg SQ three times weekly
    3. Target 44 mcg SC three times weekly (same days each week, each dose 48 hours apart)
      1. Start 8.8 mcg SQ three times weekly for 2 weeks
      2. Next 22 mcg SQ three times weekly for 2 weeks,
      3. Next 44 mcg SQ three times weekly
  3. Plegridy (Peginterferon Beta-1A)
    1. Day1: Start 63 mcg SQ
    2. Day 15: Increase to 94 mcg SQ
    3. Day 29: Increase to 125 mcg SQ
    4. Next: Continue 125 mcg SQ every 14 days
    5. Pretreat with Analgesics and Antihistamines to reduce flu-like reactions
    6. Increased drug levels and adverse reactions with renal Impairment
  • Adverse Effects
  1. Allergic Reactions (including Anaphylaxis)
  2. Local injection site inflammation
  3. Influenza-like symptoms (decreases after first 3 months)
  4. Mental health adverse effects
    1. Exacerbation of depressed mood (including increased Suicidality)
    2. Psychosis
  5. Hematologic Effects
    1. Leukopenia
    2. Thrombotic Microangiopathy
  6. Hepatotoxicity
    1. Increased liver transaminases
    2. Risk of liver failure
    3. Avoid with other Hepatotoxins
    4. Monitor Liver Function Tests
  7. Pulmonary Arterial Hypertension
  8. Congestive Heart Failure
  9. Autoimmune disorders
  10. Seizures
  • Safety
  1. Pregnancy Category C
  2. Unknown Safety in Lactation
  • Efficacy
  1. Decreases Multiple Sclerosis exacerbation frequency
  2. Decreased risk of Disability progression
  3. Decreased MS related CNS Lesions