Effectiveness: INTRON A (Interferon alfa-2b) - treated lesions showed improvement within 2 to 4 weeks after the start of treatment in a major study; maximal response to INTRON A therapy was noted 4 to 8 weeks after initiation of treatment. The response to INTRON A therapy was better in patients who had condylomata for shorter durations than in patients with lesions for a longer duration.
Basic laboratory tests, including CBC with differential, electrolytes, TSH, and LDH, and liver funtion tests should be monitored prior to treatment, and at 2, 8, and 12 weeks after the initiation of Intron A therapy.
Dose: The recommended dose is 1.0 million IU per lesion in a maximum of 5 lesions in a single course. The lesions should be injected three times weekly on alternate days for 3 weeks. An additional course may be administered at 12 to 16 weeks.
Dosage Forms for This Indication Concentration Route
Powder 10 MIU (single dose) 10 MIU/mL IL = Intralesional
Solution 25 MIU (multidose) 10 MIU/mL IL = Intralesional
-(discard multidose vial after 30 days)
Patients need a prescription for Intron-A
Patients should sign an informed consent acknowledging all risks. The specialist's office should generate a prior authorization request form for Intron A, and submit that request to the appropriate pharmacy and insurance company for the dispensing of the medication directly to the physicians office or to the patient.
Technique for Injection: The injection should be administered intralesionally using a Tuberculin or similar syringe and a 25- to 30-gauge needle. The needle should be directed at the center of the base of the wart and at an angle almost parallel to the plane of the skin (approximately that in the commonly used PPD test).
This will deliver the interferon to the dermal core of the lesion, infiltrating the lesion and causing a small wheal. Care should be taken not to go beneath the lesion too deeply; subcutaneous injection should be avoided, since this area is below the base of the lesion. Do not inject too superficially since this will result in possible leakage, infiltrating only the keratinized layer and not the dermal core.