Imiquimod

• Actinic Keratosis (AK): Treatment of multiple non-hyperkeratotic, non-hypertrophic actinic keratoses on the face or scalp in immunocompetent adults.
• Superficial Basal Cell Carcinoma (sBCC): Treatment of biopsy-confirmed primary superficial basal cell carcinoma in adults where surgical methods are not appropriate.
• External Genital and Perianal Warts: Management of external genital and perianal warts (condyloma acuminata) in patients aged 12 years and older.

Off-label Uses:

• Bowen’s disease (squamous cell carcinoma in situ)
• Molluscum contagiosum
• Certain other superficial skin cancers and viral skin infections

• Route: Topical
• Actinic Keratosis: Apply a thin layer to affected area twice weekly (e.g., Monday and Thursday) at bedtime for 16 weeks.
• Superficial Basal Cell Carcinoma: Apply once daily, five times per week (e.g., weekdays) at bedtime for 6 weeks.
• External Genital and Perianal Warts: Apply once daily, three times per week (e.g., Monday, Wednesday, Friday) at bedtime for up to 16 weeks.

Instructions:

• Apply to clean, dry skin.
• Rub gently until cream disappears.
• Leave on skin for 6–10 hours before washing off.
• Avoid occlusive dressings unless directed.

Special Populations:

• Safety in children under 12 not established.
• No dose adjustment necessary for elderly or those with renal/hepatic impairment.

Imiquimod acts as an immune response modifier by binding to Toll-like receptor 7 (TLR7) on antigen-presenting cells, stimulating the release of cytokines including interferon-alpha, tumor necrosis factor-alpha, and various interleukins. This cytokine cascade enhances innate and adaptive immune responses, promoting the clearance of virus-infected and tumor cells at the site of application.

• Absorption: Minimal systemic absorption after topical application; plasma levels typically undetectable.
• Distribution: Localized primarily to application site; systemic distribution negligible.
• Metabolism: Not significantly metabolized systemically due to minimal absorption.
• Excretion: Unknown; presumed local metabolism and elimination via skin turnover.
• Onset: Immunologic effects begin shortly after application; clinical response typically observed over weeks.

• Pregnancy: Category C – Animal studies show adverse fetal effects at high doses; human data insufficient. Use only if benefits outweigh risks.
• Lactation: Unknown if excreted in human milk; due to minimal systemic absorption, risk to infant likely low. Caution advised.
• Recommendation: Use only if clearly necessary; avoid application on breast tissue during breastfeeding.

• Immune response modifier
• Topical antiviral and antitumor agent

• Hypersensitivity to imiquimod or formulation excipients
• Application to mucous membranes, eyes, nostrils, or ears
• History of autoimmune skin disorders at the treatment site

• Monitor for severe local skin reactions (erythema, erosion, ulceration). Interrupt or reduce frequency if necessary.
• Rare systemic flu-like symptoms have been reported.
• Use cautiously in patients with autoimmune diseases.
• Avoid contact with eyes and mucous membranes.
• Safety in immunocompromised patients not established.

• Common: Local erythema, scaling, flaking, pruritus, burning, pain, crusting, and ulceration at application site.
• Less common: Hypo- or hyperpigmentation, secondary infections, rare systemic flu-like symptoms.
• Side effects usually begin within 1–2 weeks and resolve after treatment cessation or dose adjustment.

• No significant systemic drug interactions due to minimal absorption.
• Avoid concurrent use with other topical immunomodulators or irritants at the treatment site.
• No known food or alcohol interactions.

• Confirmed role as a non-invasive alternative to surgery for superficial basal cell carcinoma and actinic keratosis.
• Continued recommendation as first-line topical treatment for external genital warts.
• Emphasis on patient counseling to manage local skin reactions and improve adherence.
• Ongoing studies for expanding indications in dermatologic viral and neoplastic conditions.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep container tightly closed.
• Do not freeze.
• Follow manufacturer instructions for discard after opening.