Povidone-iodine (PVP-I), also known as iodopovidone, is an antiseptic used to disinfect the skin before and after surgery. It can be used to disinfect the hands of healthcare providers and the skin of those they care for. It can also be used on minor wounds. It can be applied to the skin in liquid or powder form.
Povidone iodine is a chemical complex of povidone, hydrogen iodide and elemental iodine. It contains 10% povidone with a total iodine content equal to 10,000 ppm or 1% total titratable iodine. It works by releasing iodine, which causes the death of a range of microorganisms.
Povidone-iodine was used commercially in 1955. It is included in the World Health Organization’s list of essential medicines. Povidone-iodine is available over the counter. It is sold under several brand names including Betadine.
Povidone-iodine is a broad spectrum antiseptic for topical application in the treatment and prevention of wound infection. It may be used in first aid for minor cuts, burns, abrasions and blisters. Povidone-iodine exhibits longer lasting antiseptic effects than tincture of iodine, due to its slow absorption via soft tissue, making it the choice for longer surgeries. Chlorhexidine is almost twice as effective in preventing infection after surgery with a similar to lower risk of adverse events,and the combination of sodium hypochlorite and hypochlorous acid in very low concentration is significantly superior for wound healing.
Consequently, PVP-I has found broad application in medicine as a surgical scrub; for pre- and post-operative skin cleansing; for the treatment and prevention of infections in wounds, ulcers, cuts and burns; for the treatment of infections in decubitus ulcers and stasis ulcers; in gynecology for vaginitis associated with candidal, trichomonal or mixed infections. For these purposes PVP-I has been formulated at concentrations of 7.5–10.0% in solution, spray, surgical scrub, ointment, and swab dosage forms; however, use of 10% povidone-iodine though recommended, is infrequently used, as it is poorly accepted by health care workers and is excessively slow to dry.
Because of these critical indications, only sterile povidone-iodine should be used in most cases. Non-sterile product can be appropriate in limited circumstances in which people have intact, healthy skin that will not be compromised or cut. The non-sterile form of Povidone iodine has a long history of intrinsic contamination with Burkholderia cepacia (a.k.a. Pseudomonas cepacia), and other opportunistic pathogens. Its ability to harbor such microbes further underscores the importance of using sterile products in any clinical setting. Since these bacteria are resistant to povidone iodine, statements that bacteria do not develop resistance to PVP-I,should be regarded with great caution: some bacteria are intrinsically resistant to a range of biocides including povidone-iodine.
Antiseptic activity of PVP-I is because of free iodine (I2) and PVP-I only acts as carrier of I2 to the target cells. Most commonly used 10% PVP-I delivers about 1–3 ppm of I2 in a compound of more than 31,600 ppm of total iodine atoms. All the toxic and staining effects of PVP-I is due to the inactive iodine only.
2.5% concentration of PVP-I buffer solution can be used to prevent neonatal conjunctivitis, especially conjunctivitis caused by Neisseria gonorrhoeae or Chlamydia trachomatis. It is unclear whether PVP-I is more effective than other methods in reducing the number of neonatal conjunctivitis cases. PVP-I appears to be well suited for this purpose because, unlike other substances, it is also effective against fungi and viruses (including HIV and herpes simplex).
It is used in pleurodesis (fusion of the pleura because of incessant pleural effusions). For this purpose, povidone-iodine is equally effective and safe as talc, and may be preferred because of easy availability and low cost.
PVP-I is contraindicated in people with hyperthyroidism (overactive thyroid gland) and other diseases of the thyroid, after treatment with radioiodine, and in people with dermatitis herpetiformis(Duhring’s disease)
The sensitization rate to this product is 0.7%.
The iodine in PVP-I reacts with hydrogen peroxide, silver, taurolidine and proteins such as enzymes, rendering them (and itself) ineffective. It also reacts with many mercury compounds, giving the corrosive compound mercury iodide, as well as with many metals, making it unsuitable for disinfecting metal piercings.
Iodine is absorbed into the body to various degrees, depending on application area and condition of the skin. As such, it interacts with diagnostic tests of the thyroid gland such as radioiodine diagnostics, as well as with various diagnostic agents used on the urine and stool, for example Guaiacum resin.