Povidone

B. V. Robinson and co-workers, PUP, M Critical Keview of the Kinetics and Toxicology of Polyvinylpyrrolidone (Povidone), Lewis, Chelsea, Mich., 1990. 

Disinfectants. Several disinfecting agents can be used in hatcheries and two are of particular interest. Because they are not considered dmg or food additive uses by FDA, povidone—iodine compounds can be used to disinfect the surface of eggs (9). Benzalkonium chloride [68424-85-1] and benzethonium chloride (quaternary ammonium compounds), are allowed at 2 mg/L by FDA to disinfect water containing fish. These compounds are also known to have therapeutic properties, especially against external bacteria (9). 

Povidone—iodine is a brown, water-soluble powder containing approximately 10% iodine. However, the amount of free iodine, which is responsible for the antimicrobial activity, is low in a concentrated solution, but is released as the solution is diluted (41). Concentrated solutions have actually been contaminated with bacteria (42). For use as an antiseptic, povidine—iodine is diluted with water or alcohol to a concentration of 1% iodine. Detergents are added if it is used as a surgical scmb. lodophors are important as broad-spectmm antiseptics for the skin, although they do not have the persistent action of some other antiseptics. They are also used as disinfectants for clinical thermometers that have been used by tuberculous patients, for surface disinfection of tables, etc, and for clean equipment in hospitals, food plants, and dairies, much as chlorine disinfectants are used. 

Of the four halogens, iodine is the weakest oxidizing agent. Tincture of iodine, a 10% solution of I2 in alcohol, is sometimes used as an antiseptic. Hospitals most often use a product called povidone-iodine, a quite powerful iodine-containing antiseptic and disinfectant, which can be diluted with water to the desired strength. These applications of molecular iodine should not delude you into thinking that the solid is harmless. On the contrary, if I2(s) is allowed to remain in contact with your skin, it can cause painful bums that are slow to heal. 

Iodine has anti-infective action against many bacteria, fungi, viruses, yeasts, and protozoa. Fbvidone-iodine (Betadine) is a combination of iodine and povidone, which liberates free iodine. Fbvidone-iodine is often preferred over iodine solution or tincture because it is less irritating to the skin. Unlike with the use of iodine, treated areas may be bandaged or taped. 

Other Agents. Allergic reactions to chlorhexidine have been observed after insertion of central catheters impregnated with this antiseptic, or after intraurethral use or topical application [26]. Only rare cases of anaphylaxis following topical use of povidone-iodine have been reported. 

Iodine compounds, e.g. free iodine, povidone-iodine... 

When iodine and povidone are combined, a chemical reaction takes place forming a complex between the two entities. Some of the iodine becomes organically linked to povidone though the major portion of the complexed iodine is in the form of tri-iodide. Dilution of this iodophor results in a weakening of the iodine linkage to the carrier polymer with concomitant increases in elemental iodine in solution and antimicrobial activity. 

Cadexomer-H is an iodophor similar to povidone-iodine. It is a 2-hydroxymethylene crosslinked (1-4) a-D-glucan carboxymethyl ether containing iodine. The compound is used especially for its absorbent and antiseptic properties in the management of leg ulcers and pressure sores where it is applied in the form of microbeads containing 0.9% iodine. 

Pharmacologic management of infections should cover the gram-positive organisms that most frequently cause access-related infections. Patients who have positive blood cultures should receive treatment tailored to the organism isolated. Preventive measures for access-related infections include mupirocin at the exit site and povidone-iodine ointment. The recommendations of the NKF for treatment of infections associated with hemodialysis are listed in Table 23-9. 

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