Version July 2025
Condylomata acuminata: Intralesional: 250,000 units (0.05 mL) per wart twice weekly for a maximum of 8 weeks; maximum dose per treatment session: 2.5 million units (0.5 mL). 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).
There are no dosage adjustments provided in the manufacturer’s labeling.
There are no dosage adjustments provided in the manufacturer’s labeling.
Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Adverse reaction incidence noted below is specific to intralesional administration in patients with condylomata acuminata.
>10%:
Central nervous system: Headache (31%), chills (14%), fatigue (14%)
Hematologic & oncologic: Decreased white blood cell count (11%)
Neuromuscular & skeletal: Myalgia (45%)
Respiratory: Flu-like symptoms (30%; includes headache, fever, and/or myalgia; abated with repeated dosing)
Miscellaneous: Fever (40%)
1% to 10%:
Central nervous system: Malaise (9%), dizziness (9%), depression (2%), insomnia (2%), vasodepressor syncope (2%), hyperesthesia (tongue: 1%), paresthesia (1%)
Dermatologic: Diaphoresis (2%), pruritus (2%)
Endocrine & metabolic: Increased thirst (1%)
Gastrointestinal: Nausea (4%), vomiting (3%), dyspepsia (3%), diarrhea (2%), dysgeusia (1%)
Hematologic & oncologic: Adenopathy (groin: 1%)
Neuromuscular & skeletal: Arthralgia (5%), back pain (4%), muscle cramps (1%)
Ophthalmic: Visual disturbance (1%)
Respiratory: Rhinitis (2%), epistaxis (1%), pharyngitis (1%)
<1%, postmarketing, and/or case reports: Dysuria, hepatotoxicity (idiosyncratic; Chalasani 2014), hot flash, lack of concentration, nervousness, skin photosensitivity
Hypersensitivity to human interferon alpha proteins or any component of the formulation; anaphylactic sensitivity to mouse immunoglobulin (IgG), egg protein, or neomycin.
Concerns related to adverse effects:
• Flu-like symptoms: Flu-like symptoms are common; may aggravate debilitating conditions.
• Hypersensitivity reactions: Discontinue use if signs/symptoms of hypersensitivity reactions occur (eg, urticaria, angioedema, bronchoconstriction, anaphylaxis).
Disease-related concerns:
• Bone marrow suppression: Use with caution in patients with severe myelosuppression.
• Cardiovascular disease: Use with caution in patients with preexisting cardiovascular disease (eg, unstable angina, uncontrolled CHF). In a scientific statement from the American Heart Association, interferon has been determined to be an agent that may either cause reversible direct myocardial toxicity or exacerbate underlying myocardial dysfunction (magnitude: moderate/major) (AHA [Page 2016]).
• Coagulation disorders: Use with caution in patients with coagulation disorders (eg, thrombophlebitis, pulmonary embolism, hemophilia).
• Diabetes: Use with caution in patients with diabetes with ketoacidosis.
• Pulmonary disease: Use with caution in patients with severe pulmonary disease (eg, chronic obstructive pulmonary disease).
• Seizure disorder: Use with caution in patients with seizure disorders.
Dosage form specific issues:
• Albumin: Contains albumin, which may carry a remote risk of transmitting Creutzfeldt-Jakob or other viral diseases.
• Product variability: Due to differences in manufacturing, strength, and type of interferon, do not change from one brand of interferon to another; a change in dosage may be required.
Other warnings/precautions:
• Appropriate use: Patients should be selected for therapy based on a number of factors: the locations and sizes of the lesions, past treatment and response, and the patient's ability to comply with the treatment regimen. Therapy is particularly useful for patients who have not responded satisfactorily to other treatment modalities (eg, podophyllin resin, surgery, laser or cryotherapy).
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Solution, Injection:
Alferon N: 5,000,000 units/mL (1 mL [DSC])
No
Solution (Alferon N Injection)
5000000 units/mL (per mL): $722.89
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Inject into base of wart with a 30-gauge needle. For large warts, dose may be injected at several points around the outside edge of the wart (total dose: 0.05 mL/wart).
An FDA-approved patient medication guide, which is available with the product information and at http://www.fda.gov/downloads/Drugs/DrugSafety/ucm088613.pdf, must be dispensed with this medication.
Condylomata acuminata: Intralesional treatment of refractory or recurring external condylomata acuminata (venereal or genital warts) in patients 18 years of age or older.
Alferon may be confused with Alkeran
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Aldesleukin: Interferons (Alfa) may increase adverse/toxic effects of Aldesleukin. In particular, risks of myocardial and renal toxicity may be increased by this combination. Management: Consider using lower doses to minimize toxicity of this combination. Only coadminister aldesleukin and interferons (alfa) in patients in whom potential benefits outweigh the risk of severe toxicity. Monitor renal and cardiac function closely if combined. Risk D: Consider Therapy Modification
Fluorouracil Products: Interferons (Alfa) may increase serum concentration of Fluorouracil Products. Risk C: Monitor
Methadone: Interferons (Alfa) may increase serum concentration of Methadone. Risk C: Monitor
Ribavirin (Oral Inhalation): Interferons (Alfa) may increase adverse/toxic effects of Ribavirin (Oral Inhalation). Hemolytic anemia has been observed. Risk C: Monitor
Ribavirin (Systemic): Interferons (Alfa) may increase adverse/toxic effects of Ribavirin (Systemic). Hemolytic anemia has been observed. Risk C: Monitor
Telbivudine: Interferons (Alfa) may increase adverse/toxic effects of Telbivudine. Specifically, the risk of peripheral neuropathy may be increased. Risk X: Avoid
Vitamin K Antagonists: Interferons (Alfa) may increase anticoagulant effects of Vitamin K Antagonists. Risk C: Monitor
Zidovudine: Interferons may increase adverse/toxic effects of Zidovudine. Interferons may decrease metabolism of Zidovudine. Risk C: Monitor
Menstrual irregularities have been reported; effective contraception is recommended during treatment.
Animal reproduction studies have not been conducted.
It is not known if interferon alfa-n3 is excreted in breast milk. Due to the potential for serious adverse reactions in the nursing infant, the manufacturer recommends a decision be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of treatment to the mother.
Interferons interact with cells through high affinity cell surface receptors. Following activation, multiple effects can be detected including induction of gene transcription. Inhibits cellular growth, alters the state of cellular differentiation, interferes with oncogene expression, alters cell surface antigen expression, increases phagocytic activity of macrophages, and augments cytotoxicity of lymphocytes for target cells
