Source: Υπουργείο Υγείας (CY) Revision Year: 2021 Publisher: MUNDIPHARMA PHARMACEUTICALS LTD., 13, Othellos str., Dhali Industrial Zone, P.O. Box 23661, 1685 Nicosia, Cyprus Tel: +357 22815656 Fax: +357 22487833 e-mail: info@mundipharma.com.cy
Pharmacotherapeutic group: Antiseptics
ATC code: D08AG02
Povidone-Iodine is a complex of the polymer polyvinylpyrrolidone with iodine (Povidone-Iodine) which, after application, continues to deliver iodine over a period of time. Elemental iodine (I2) has long been known as a highly effective microbicidal agent that rapidly kills bacteria, viruses, fungi and some protozoa in vitro. Two mechanisms are involved: free iodine rapidly causes microbial killing, whereas iodine bound to the polymer serves as a reservoir. As the preparation comes in contact with the skin and mucous membranes, more and more iodine dissociates from the polymer. The free iodine reacts with oxidizable –SH or –OH groups of the amino acids in the enzymes and structural proteins of microorganisms thereby inactivating and killing these enzymes and proteins. Most vegetative microorganisms are killed in less than a minute in vitro, with many destroyed within 15 to 30 seconds. During this process, iodine is decolorized; thus the intensity of brown coloration serves as indicator of its effectiveness. Repeated dosing may be required upon discoloration. Resistance has not been reported.
In normal individuals, topical application results in very little systemic iodine absorption; with vaginal administration, however, iodine absorption is rapid and serum concentrations of total iodine and inorganic iodide are increased significantly. This product is intended for topical application to the skin and wounds.
Absorption and, in particular, renal elimination of povidone depend on the (mean) molecular weight (of the mixture). For molecular weights of more than 35,000 to 50,000, retention must be expected.
The behavior of absorbed iodine or iodide in the organisms is largely similar to that of iodine taken up by other routes. The volume of distribution corresponds to approximately 38% of body weight in kg.
Elimination is almost exclusively by renal route with a clearance of 15 to 60 ml plasma/min depending on serum iodine level and creatinine clearance.
In experimental animal investigations (mouse, rat rabbit, dog), acutely toxic effects were found after systemic administration (oral, i.p., i.v.) only with excessively high doses that are of no significance for the local use of povidone-iodine.
Subchronic and chronic tests for toxicity were carried out on rats, among other animals, in the form of the admixture of Povidone-Iodine (10% available iodine) into the feed in dosages of between 75 and 750 mg Povidone-Iodine per day and kg body weight for up to 12 weeks. After the Povidone-Iodine addition was stopped, only the practically completely reversible and
dose-dependent rises in PBI (protein-bound iodine) in the serum and non-specific histopathologic changes in the thyroid gland were observed. Similar changes also occurred in the control group, which received potassium iodide in iodine-equivalent amounts instead of Povidone-Iodine.
A mutagenic action for Povidone-Iodine can be ruled out. No carcinogenicity studies have been conducted; no information is, therefore, available.
Because of the ability of iodine to pass through the placenta and the sensitivity of the foetus to pharmacologic doses of iodine, no larger amounts of iodine should be absorbed during pregnancy. The use of Povidone-Iodine in obstetrics may lead to a significant rise in serum iodine concentration in the mother and to transient hypofunction of the thyroid gland with elevation of TSH (thyroid-stimulating hormone) concentration in the neonate. Moreover, iodide is concentrated in the milk, as compared with the serum.
© All content on this website, including data entry, data processing, decision support tools, "RxReasoner" logo and graphics, is the intellectual property of RxReasoner and is protected by copyright laws. Unauthorized reproduction or distribution of any part of this content without explicit written permission from RxReasoner is strictly prohibited. Any third-party content used on this site is acknowledged and utilized under fair use principles.
