Inrebic
Inrebic
Generic Name
Inrebic
Mechanism
- TLR7 Agonist: Activation of Toll‑like receptor 7 on keratinocytes and Langerhans cells.
- Cytokine Induction: Drives production of interferon‑α, tumor necrosis factor‑α, and interleukin‑12.
- Innate Immunity Activation: Enhances natural killer cell activity and promotes CD8⁺ cytotoxic T‑cell expansion.
- Antiviral & Antitumor Response: Resultant cytokine milieu causes apoptosis of HPV‑infected cells and limits viral replication.
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Pharmacokinetics
| Parameter | Details |
| Absorption | Limited local dermal uptake; less than 0.3 % systemic absorption when applied to genital skin. |
| Distribution | Primarily retained in epidermis; minimal systemic distribution. |
| Metabolism | Not extensively metabolized; retains active form. |
| Excretion | Eliminated unchanged via feces; negligible renal excretion. |
| Half‑life | Local action sustained by cytokine induction rather than drug presence; systemic half‑life > 60 h. |
| Drug Interactions | No clinically relevant interactions due to minimal systemic exposure. |
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Indications
- External genital and anal warts (condyloma acuminata) caused by HPV 6 and 11.
- Must be used in immunocompetent adults; not approved for vulval, perineal, or other mucosal surfaces.
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Contraindications
- Hypersensitivity to imiquimod or any cream component.
- Pregnancy: Avoid use; insufficient safety data; potential local absorption.
- Immunocompromised patients: risky due to exaggerated systemic immune activation.
- Pregnancy‑loss: Avoid or monitor closely.
- Contact with eyes/mucosa: Prevent exposure.
Dosing
- Adult regimen:
1. Apply 1–2 layers of cream to all lesions and surrounding skin.
2. Frequency: 3–4 times per week (e.g., Monday, Wednesday, Friday, Sunday).
3. Duration: Continue until the last *new* lesion ceases to appear and the patient has completed at least 4 weeks of therapy; can extend to 16 weeks if resolution is slow.
• Treatment pause: 1–2 weeks after every 4–6 weeks of continuous use to prevent skin burnout.
• Application: Use a smooth, gentle technique; avoid tearing the skin.
• Dryness: Allow the area to dry fully before sexual activity or covering; wore breathable underwear.
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Adverse Effects
| Adverse Effect | Frequency | Notes |
| Local inflammatory reaction (redness, itching, burning, swelling) | 80–90 % | May mimic active wet wart; usually peaks within 7–10 days. |
| Eczema‑like dermatitis | < 10 % | Discontinue if severe. |
| Burning sensation | 20–30 % | Often resolves with continued use. |
| Pruritus | 20–25 % | Antihistamines may help. |
| Flu‑like symptoms | < 5 % | Transient headache, fever. |
| Hypersensitivity rash | < 2 % | Treat with antihistamines; consider stopping. |
| Transient liver enzyme elevation | Rare | Monitor in patients with pre‑existing liver disease. |
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Monitoring
- Lesion Response: Weekly visual inspection for size reduction and new lesions.
- Local Skin Reaction: Grade inflammation to 0‑4 scale; modify frequency if ≥ grade 3.
- Pregnancy Test: If female of reproductive age, screening before initiation.
- Liver Function Tests (LFTs): Monthly in patients with hepatic disease or if systemic symptoms arise.
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Clinical Pearls
- Maximum Layer Limit: Never exceed 2 layers; excess cream increases systemic absorption without added benefit.
- Flare‑Back Strategy: For recalcitrant warts, extend intervals between application cycles (e.g., 2 weeks on, 1 week off).
- Patient Education: Emphasize that initial intense skin irritation may indicate efficacious immune activation—do not stop prematurely.
- Co‑therapy: Use with topical steroid only for severe inflammatory reaction; avoid during active wart removal.
- Efficacy in HIV‑negative patients: > 80 % clearance at 12 weeks; may need > 12 weeks in HIV‑positive individuals.
- Pregnancy Precautions: Use barrier contraception during treatment and for 6 weeks after last dose to avoid inadvertent exposure.
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• Key take‑away: *Inrebic* works by turning the skin into a localized immune factory, harnessing innate cytokine pathways to eradicate HPV. Proper dosing, patient education, and monitoring of local inflammation are critical to maximize benefits while minimizing unnecessary side‑effects.