Interferon Beta-1A Subcutaneous Injection and Zidovudine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Zidovudine
Interferon Beta-1A Subcutaneous Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Zidovudine toxicity (lethargy, fatigue, anemia)
Interaction Deep Dive
Combined therapy with recombinant interferon beta and zidovudine has resulted in a significant decrease in zidovudine clearance in AIDS patients12. A similar interaction would be expected with natural human interferon beta.
Why it happens (mechanism)
Decreased zidovudine glucuronidation
Literature reports
2 reports — tap to read
a) The effect of combination therapy of recombinant interferon beta and zidovudine on the rates of metabolism of zidovudine in AIDS patients was investigated. Zidovudine was given orally (200 mg every four hours) for eight weeks prior to initiation of interferon beta therapy. The half-life of zidovudine was increased approximately 2 fold by day 15. The elimination rate constant for zidovudine was diminished significantly during interferon beta therapy, at days 3 and 15. The volume of distribution of zidovudine was 2 L/kg at day 0 and increased to 3.2 and 3.5 L/kg on days 3 and 15, respectively. The results indicate that interferon beta inhibits the rate of zidovudine metabolism in AIDS patients 1.
b) In AIDS patients treated with zidovudine, the addition of interferon beta resulted in a 67% decrease in zidovudine clearance within three to four days. At two weeks, zidovudine clearance was reduced by 90% 2.
Common questions
Can I take Interferon Beta-1A Subcutaneous Injection and Zidovudine together?
Zidovudine toxicity (lethargy, fatigue, anemia) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Interferon Beta-1A Subcutaneous Injection and Zidovudine interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Interferon Beta-1A Subcutaneous Injection or Zidovudine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (2)
- Nokta M, Loh JP, Douidar SM, et al: Metabolic interaction of recombinant interferon-beta and zidovudine in AIDS patients. J Interferon Res 1991; 11:159-164.
- Ruedy J, Schechter M, & Montaner JS: Zidovudine for early human immunodeficiency virus (HIV) infection: who, when, and how?. Ann Intern Med 1990; 112:721-723. PubMed
Keep reading about Zidovudine
Keep reading about Interferon Beta-1A Subcutaneous Injection
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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