2020A02 Compare and contrast povidone iodine and alcoholic chlorhexidine as skin antiseptic agents.

 

 

Povidone iodine

Alcoholic chlorhexidine

General:

 

 

   Ingredients

Polyvinylpyrrolidone (polymer)

Diatomic iodine

10% w/v

Chlorhexidine gluconate (0.5%)

Isopropanol 70%

   Mechanism

Oxides proteins, nucleotides

Both disrupt the cell membrane

Antimicrobial effect:

 

 

   Bacteria

Yes (G+ > G-)

Yes

   Viruses

Yes (less so)

Yes

   Fungi

Yes

Yes

   Spores

Yes

No

   Resistance

No

Yes

Time course:

 

 

   Onset

Slower

Faster (alcohol kills quickly)

   Duration

Long (releases iodine slowly)

Long (chlorhex binds epidermis, prevents regrowth)

   Inactivation by body fluids

Yes (apply to clean skin only)

No

Efficacy:

 

 

   Surgical site

Less effective

More effective (risk ↓~40%)

   Vascular access site

Less effective

More effective (risk ↓~50%)

Toxicity:

 

 

   Brain & neuraxis

Less (but max 0.5% skin prep)

More

   Middle ear

Less

More

   Cornea

Less

More

   Mucous membrane

Less

More

   Abdominal viscera

Less

More

Other AEs:

 

 

   Flammability

No

Yes (alcohol). Must allow to dry.

   Allergy/anaphylaxis

Less common

(to povidone, not iodine)

More common

 

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