Usage
Povidone Iodine is a broad-spectrum antiseptic used for skin disinfection before and after surgery. It is also utilized for minor wound care, and can be applied to disinfect the hands of healthcare providers and the skin of patients. Other approved uses include treatment of minor burns, cuts, abrasions, and infections. It is effective against gram-positive and gram-negative bacteria, fungi, protozoa, tubercle bacilli, viruses, and bacterial spores.
Pharmacological Classification: Antiseptic, disinfectant.
Mechanism of Action: Povidone iodine releases free iodine, which penetrates microbial cell membranes and interacts with proteins, nucleotides, and fatty acids within the cytoplasm and cytoplasmic membrane, ultimately causing cell death.
Alternate Names
- Iodopovidone
- Polyvidone iodine
Brand Names:
- Betadine
- Wokadine
- Pyodine (and others)
How It Works
Pharmacodynamics: Povidone-iodine exerts its antiseptic effect through the release of free iodine. This free iodine rapidly penetrates the cell walls of microorganisms, disrupting protein synthesis and altering cell membranes, leading to cell death. The broad-spectrum activity encompasses bacteria (gram-positive and gram-negative), fungi, viruses, protozoa, and some spores.
Pharmacokinetics: Absorption of iodine from intact skin is minimal. However, absorption can increase significantly with application to large wounds, burned skin, or mucous membranes. Absorbed iodine is converted to iodide and is primarily excreted by the kidneys. Some iodine is also excreted in the feces and through breast milk.
Mode of Action: Free iodine acts directly on microbial cells, causing:
- Oxidation of cellular components: Disrupts essential metabolic processes.
- Protein denaturation: Inactivates crucial enzymes and structural proteins.
- Membrane disruption: Compromises cell integrity.
Elimination Pathways: Primarily renal excretion.
Dosage
Standard Dosage
Adults: Topical application to affected area 1-3 times daily as a solution, ointment, or swab. For surgical skin prep, apply to the area and allow to dry.
Special Cases:
- Elderly Patients: Similar to adult dosing. Monitor for thyroid function.
- Patients with Renal Impairment: Use with caution. Monitor for iodine toxicity.
- Patients with Hepatic Dysfunction: No specific dose adjustments, but monitor renal function due to shared excretory pathways.
- Patients with Comorbid Conditions: Those with thyroid disorders should use with caution and under close monitoring due to potential for iodine-induced hypothyroidism or hyperthyroidism.
Clinical Use Cases
- Intubation: Apply solution to the skin around the insertion site.
- Surgical Procedures: Apply solution or scrub to the surgical site prior to incision.
- Mechanical Ventilation: Apply solution to the skin around tracheostomy sites if present.
- Intensive Care Unit (ICU) Use: Use for skin disinfection and wound care as needed.
- Emergency Situations: Use for wound antisepsis.
Dosage Adjustments:
No specific dose adjustments are based on pharmacogenomic considerations, but monitor patients with thyroid disorders, kidney disease, or patients applying it in large areas.
Side Effects
Common Side Effects:
- Mild skin irritation (redness, itching, burning).
- Temporary stinging at the application site.
Rare but Serious Side Effects:
- Allergic reactions (rash, hives, swelling, difficulty breathing).
- Severe skin reactions (blistering, peeling).
- Thyroid dysfunction (hypothyroidism or hyperthyroidism with prolonged or extensive use).
- Metabolic acidosis (with extensive use on large wounds).
- Hypernatremia (with extensive use on large wounds).
- Acute renal failure (with extensive use on large wounds).
Long-Term Effects:
- Hypothyroidism (with prolonged or extensive use).
- Hyperthyroidism (with prolonged or extensive use).
- Contact dermatitis.
Adverse Drug Reactions (ADR):
- Anaphylaxis (rare but requires immediate medical attention).
- Angioedema.
Contraindications
- Hypersensitivity to iodine or povidone.
- Neonates (for some formulations).
- Use over large areas of the body or for prolonged periods.
- Patients with burns (some formulations).
Drug Interactions
- Lithium: Concurrent use may increase the risk of hypothyroidism.
- Hydrogen peroxide: Concurrent use may reduce the effectiveness of both agents.
- Enzymatic debriding agents: Povidone-iodine can inactivate these agents.
- Silver sulfadiazine: Povidone iodine may inactivate silver sulfadiazine.
- Metallic salts: Povidone-iodine may form insoluble iodides with metals like mercury, silver or lead.
Pregnancy and Breastfeeding
Pregnancy Category: B (animal studies have not demonstrated a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women. or animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester).
Use with caution during pregnancy and lactation. Iodine can cross the placenta and is excreted in breast milk. Monitor infants for thyroid dysfunction. Minimize use to smallest effective area and shortest duration.
Drug Profile Summary
- Mechanism of Action: Releases free iodine, which disrupts microbial cell structure and function.
- Side Effects: Skin irritation, allergic reactions, thyroid dysfunction (with prolonged use).
- Contraindications: Hypersensitivity to iodine, neonates (for some formulations).
- Drug Interactions: Lithium, hydrogen peroxide, enzymatic debriding agents.
- Pregnancy & Breastfeeding: Use with caution; monitor infant thyroid function.
- Dosage: Topical application 1-3 times daily.
- Monitoring Parameters: Thyroid function tests (with prolonged or high-dose use).
Popular Combinations
Povidone-iodine is often used alone.
Precautions
- General Precautions: Screen for iodine sensitivity. Avoid use in patients with thyroid disorders or those receiving lithium therapy, unless under close supervision. Avoid contact with eyes.
- Specific Populations:
- Pregnant Women: Use only if clearly needed.
- Breastfeeding Mothers: Use with caution and monitor infant’s thyroid function.
- Children & Elderly: Use with caution and monitor for thyroid dysfunction.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Povidone Iodine?
A: Topical application 1-3 times daily to the affected area. Dosage may vary with product formulation (solution, ointment, swab).
Q2: How does Povidone Iodine work?
A: It releases free iodine, which disrupts microbial cell structure and function, resulting in cell death.
Q3: Is Povidone Iodine safe during pregnancy?
A: Use with caution during pregnancy and lactation. Iodine can cross the placenta and is excreted in breast milk. Monitor infants for thyroid dysfunction.
Q4: What are the common side effects of Povidone Iodine?
A: Common side effects include mild skin irritation, itching, and burning sensation at the application site.
Q5: Can Povidone Iodine be used on open wounds?
A: Yes, it can be used on minor cuts, abrasions, and burns. For larger or deeper wounds, consult a physician.
Q6: What are the contraindications for Povidone Iodine use?
A: Contraindications include hypersensitivity to iodine, neonates (for some formulations), and use over large areas of the body.
Q7: Does Povidone Iodine interact with other medications?
A: Yes, it can interact with lithium, hydrogen peroxide, and some wound care products. Consult a physician about potential drug interactions.
Q8: How should Povidone Iodine be stored?
A: Store at room temperature away from direct sunlight and excessive heat.
Q9: What should I do if I accidentally ingest Povidone Iodine?
A: Contact a poison control center or seek immediate medical attention.
Q10: Can Povidone Iodine be used for vaginal infections?
A: Yes, povidone-iodine vaginal products are available for the treatment of certain vaginal infections, but consultation with a gynecologist is recommended.
