Povidone-iodine (PVP-I) is a brown-coloured antiseptic used to disinfect skin before injections and surgery and to treat wounds. It also comes as mouthwash solutions and gynaecological washes.
Also known as: Betadine, PVPI
Povidone-iodine applied to extensive wounds or mucosa is absorbed in sufficient amounts to affect the thyroid, potentially destabilising antithyroid therapy and interfering with thyroid function tests.
Systemically absorbed iodine load that alters thyroid response: the Prontuário (Povidone-iodine 13.1.1) states it "may be absorbed in sufficient quantity to affect the thyroid", requiring caution "in patients with thyroid disorders", and that it "may interfere with the results of thyroid function tests".
TSH, free T4, T3 and clinical signs of hypo- or hyperthyroidism.
Recently developing goitre, tachycardia, worsening hyperthyroidism, lethargy (hypothyroidism).
Avoid prolonged application to extensive or mucosal areas in patients on antithyroid drugs; prefer chlorhexidine; interpret TSH and free T4 with caution in the weeks after exposure.
INFARMED Prontuário Terapêutico (11th ed., 2012), Povidone-iodine 13.1.1 — systemic absorption affecting the thyroid and interfering with thyroid tests.
Povidone-iodine provides a systemically absorbed iodine load that may affect the thyroid and destabilise propylthiouracil therapy, besides interfering with thyroid function tests.
As with carbimazole, absorbed iodine alters thyroid response and may counteract or confuse the antithyroid effect; the Prontuário (Povidone-iodine 13.1.1) documents this absorption and the interference with thyroid tests.
TSH, free T4, T3, signs of hypo- or hyperthyroidism.
Worsening hyperthyroidism or developing hypothyroidism, goitre.
Avoid application to extensive or mucosal areas during antithyroid therapy; prefer chlorhexidine; reassess TSH and free T4 after exposure.
INFARMED Prontuário Terapêutico (11th ed., 2012), Povidone-iodine 13.1.1 — systemic absorption affecting the thyroid, and 8.3 Thyroid hormones and antithyroid drugs (Propylthiouracil entry).
No documented food or drink interactions.
Iodine absorption can trigger thyrotoxicosis (Jod-Basedow effect) in thyroid disease — avoid extensive/prolonged use.
Do not use on extensive burns of patients with uncontrolled thyroid disease.
Site monograph (povidone-iodine — uncontrolled thyroid disease without assessment); Prontuário 13.4.
Absorbed iodine crosses the placenta and causes fetal/neonatal hypothyroidism — avoid extensive use in the 2nd/3rd trimesters.
Limited, small use in obstetrics; never occlusive.
Site monograph (iodine absorption → fetal/neonatal hypothyroidism).
Annex 1 refers to Iodides: use only if "the clinical benefit clearly outweighs the potential risks". Free iodine crosses the placenta and, with repeated/extensive use (vaginal or widespread skin application, especially from the 2nd trimester), can cause fetal hypothyroidism and goitre due to iodine overload — the fetal thyroid is sensitive until ~36 weeks. Point application on intact skin is safe.
Point topical use (pre-procedure antisepsis) is safe; avoid repeated vaginal applications, extensive baths and prolonged use, especially in the 2nd–3rd trimesters. Monitor newborn thyroid if extensive maternal use.
Do not use on infants or on the breasts/genitals of breastfeeding mothers (infant absorption); use on distant skin is compatible.
Prontuário Terapêutico INFARMED — Annex 1: Potassium iodide/Iodides/Povidone-iodine (l. 40609-12). EMC-UK (MHRA) — Povidone-Iodine SmPC.
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Broad-spectrum antisepsis (bacteria, fungi, viruses, spores) with onset in seconds and duration while dry on skin.
Free iodine oxidises bacterial nucleoproteins and enzymes (sulphydryl, hydroxyl and amine groups), killing microorganisms by irreversible denaturation.
Topical: relevant systemic absorption only on extensive mucosa, burns or prolonged use.
Iodine absorption through damaged skin/mucosa; iodine accumulates in the thyroid (active uptake) and is excreted in urine.
~ 2 h (cutaneous povidone); iodine ~ 6–8 h.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
