Generic Name

Betadine®

Mechanism

• Disruption of microbial cell membranes through I₂ released from PVP‑I, forming iodo‑species that oxidize and iodinate cellular components (proteins, nucleic acids) → microbial death.
• Inhibition of enzyme systems critical to bacterial and fungal metabolism.
• The complex protects iodine from rapid volatilization, allowing sustained release and activity over a broad pH range (2–7).
• Activity remains high against Gram‑positive and Gram‑negative bacteria, fungi, spores, and enveloped viruses (e.g., HSV, HIV, influenza).

Pharmacokinetics

Indications

• Pre‑operative skin preparation for general, cardiac, and ophthalmic surgery.
• Wound irrigation and disinfection of superficial wounds, lacerations, and abrasions.
• Burn care (especially superficial burns) to reduce infection risk.
• Oral and nasal mucosa rinsing for pre‑operative de‑colonization.
• Ophthalmic use (concentration 0.5–1.25%) for infections such as blepharitis and conjunctivitis.
• Infection prevention in invasive device insertion (e.g., catheter line sites, surgical drains).
• Field medicine for quick disinfection in austere environments.

Contraindications

• Contraindicated in patients with *iodine allergy* or *thyroid disorders* (hyperthyroidism, Hashimoto's thyroiditis) due to potential iodine overload.
• Caution in *pregnant* or *lactating* patients; topical use is generally safe but avoid intra‑ocular application.
• Avoid on *extensive burns*, *corrosive injuries*, or *ulcerative lesions* where systemic absorption risks increase.
• Do not use simultaneously with other iodine products or topical antibiotics that release iodine.
• Risk of systemic hypothyroidism if used >1 % with large surface area or prolonged periods.

Dosing

• Preparation: Use sterile containers; avoid contact with glass (iodine can leach).
• Contact time: Minimum 30 s for optimal activity; longer contact improves efficacy (>5 min).
• Adjuncts: Use in combination with sterile gauze or antiseptic‑adherent dressings for prolonged contact.

Adverse Effects

• Local: Skin irritation, erythema, dryness, desquamation, hyperpigmentation, or contact dermatitis.
• Systemic:
• Allergic reaction: rash, urticaria, anaphylaxis in iodine‑allergic patients.
• Thyroid dysfunction: transient hypothyroidism, hyperthyroidism, or thyrotoxicosis after extensive use or in susceptible individuals.
• Methemoglobinemia: rare with topical use, but possible with high concentrations or intravenous preparations.
• Ophthalmic: Iodine irritation, blurred vision, corneal epithelium damage if used at >1.25 %.

Monitoring

• Thyroid function tests (TSH, free T₄, total T₃) if prolonged or extensive topical use is anticipated.
• Serum iodine levels in high‑risk patients (e.g., pregnant women, patients with renal impairment).
• Skin assessment: Look for signs of contact dermatitis or delayed wound healing.
• Visual acuity and slit‑lamp exam if used intra‑ocular or peri‑ocular.

Clinical Pearls

• “PVP‑I is not an antibiotic”: It prevents infection but does not treat bacterial superinfection. Reserve antibiotics for clinically infected wounds.
• Use a “pre‑operative chlorhexidine‑plus‑povidone‑iodine” strategy: For heavily contaminated skin, a double‑step prep (chlorhexidine first, rinse, then PVP‑I) can reduce bacterial load more than either agent alone.
• Avoid PVP‑I on eschar: Because iodine penetrates poorly through non‑breathing tissue, eschar debridement or alternative antiseptics (e.g., chlorhexidine) are preferred.
• Burns: For first‑degree or superficial partial‑thickness burns, 1 % PVP‑I rinses can decrease infection; for deeper burns, use sterile gauze soaked in saline or specialized burn wound solutions.
• Ophthalmology: A 0.25–0.5 % solution is safe for short‑term pre‑operative ocular prep; avoid for long‑term therapy due to corneal toxicity.
• In pregnancy: Topical povidone‑iodine is classified as “Category C” but is frequently used because systemic absorption is minimal; still, apply only on the surgical site and avoid eye exposure.
• Thyro‑toxic patients: If using Betadine post‑operatively, consider oral levothyroxine or T₄ supplements; routine monitoring is essential.
• Product storage: Keep in opaque containers at 2–8 °C; avoid sunlight to prevent iodine degradation.

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• *All information is intended for educational purposes and should be cross‑verified with the latest clinical guidelines and the product’s labeling.*