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Interferon alfa-n3

Generic name: interferon alfa-n3 [ IN-ter-FEER-on-AL-fa ]
Brand name: Alferon N
Dosage form: injectable solution (5000000 intl units/mL)
Drug class: Interferons

Medically reviewed by on May 23, 2023. Written by Cerner Multum.

What is interferon alfa-n3?

Interferon alfa-n3 is used to treat genital warts in adults. interferon alfa-n3 is for use only on the outside of the body.

Interferon alfa-n3 is usually given after other treatments have failed.

Interferon alfa-n3 may also be used for purposes not listed in this medication guide.

Interferon alfa-n3 side effects

Get emergency medical help if you have signs of an allergic reaction (hives, chest tightness, wheezing, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Interferon alfa-n3 may cause serious side effects. Call your doctor at once if you have:

Common side effects of interferon alfa-n3 may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Call your doctor if your genital warts do not completely clear up within 3 months after your last injection of interferon alfa-n3.

Before taking this medicine

Tell your doctor if you have ever had:

Tell your doctor if you are pregnant or breastfeeding.

How is interferon alfa-n3 given?

Interferon alfa-n3 is injected directly into each genital wart lesion, usually given 2 times per week for up to 8 weeks.

A healthcare provider will give you this injection.

Your lesions may only partially clear up after 8 weeks, but you may notice improvement even after your treatment ends.

Tell your doctor if your warts do not completely clear up within 3 months after your last injection.

Interferon alfa-n3 dosing information

Usual Adult Dose for Condylomata Acuminata:

Refractory or recurring external condylomata acuminata:
0.05 mL (250,000 international units) per wart, injected intralesionally 2 times a week for up to 8 weeks
-The maximum recommended dose per treatment session is 0.5 mL (2.5 million international units).
-Therapy should not be repeated for at least 3 months after the initial 8-week course of therapy (unless existing warts grow or new warts appear).

Use: For the intralesional treatment of refractory or recurring external condylomata acuminata

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your interferon alfa-n3 injection.

What happens if I overdose?

In a medical setting an overdose would be treated quickly.

What should I avoid while receiving interferon alfa-n3?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect interferon alfa-n3?

Other drugs may affect interferon alfa-n3, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.