Iodoquinol is a halogenated 8-hydroxyquinoline anti-infective agent.
Although iodoquinol, in a suitable dermatologic vehicle alone or in combination with coal tar, has been used topically in the treatment of bacterial and fungal infections of the skin, the drug principally is used in combination with hydrocortisone for the topical treatment of subacute and chronic dermatoses. There is a lack of substantial evidence that these topical preparations containing iodoquinol are effective for their purported uses. Although iodoquinol previously was used in the treatment of diaper rash (diaper dermatitis), use of the drug in children currently is not recommended.104,114 (See Cautions.)
Iodoquinol also has been used as a shampoo (no longer commercially available in the US) for the control of seborrheic dermatitis of the scalp. However, relapse usually occurs when the medication is discontinued.
For the use of iodoquinol in intestinal amebiasis and other conditions, see 8:30.04
Iodoquinol is applied topically to the skin; contact with the eyes should be avoided.
When iodoquinol is used in combination with hydrocortisone for the treatment of subacute and chronic dermatoses, a cream containing iodoquinol 3% is applied topically to the affected area of skin 3 or 4 times daily as directed.108
Iodoquinol usually is well tolerated when applied to inflamed skin. Irritation occurs very infrequently and sensitization is rare. Cross-sensitivity (independent of the particular halogen) occurs between halogenated hydroxyquinolines; the drug should be discontinued if it appears to produce or increase skin irritation. Iodoquinol should not be used over large areas for long periods or by patients with iodine intolerance. The drug should not be allowed to come in contact with the eyes. Iodoquinol can stain the skin and fabrics.108 Prolonged use of the drug can result in overgrowth of nonsusceptible organisms, which may require appropriate therapy.108 Preparations containing iodoquinol are contraindicated in individuals with known hypersensitivity to the drug or any ingredient in the formulation.
When iodoquinol is used topically in fixed combination with hydrocortisone, the usual precautions associated with topical corticosteroid therapy should be observed.108 (See Cautions in the Topical Corticosteroids General Statement 84:06.08.)
Percutaneously absorbed iodoquinol, like other halogenated hydroxyquinolines containing iodine, may interfere with certain thyroid function tests (e.g., protein-bound iodine);101,108,109,111,126,127 therefore, the manufacturer recommends that at least 1 month elapse between discontinuance of topical therapy with the drug and performance of these tests.108 Iodoquinol also may produce false-positive results in the ferric chloride test for phenylketonuria when the drug is present in urine or the diaper.108
Although statements in the iodoquinol and hydrocortisone cream labeling suggest that the drug can be used in pediatric patients with appropriate precautions (e.g., do not use tight-fitting diapers or other garments that may be occlusive over treated areas), the manufacturer states that safety and efficacy in children younger than 12 years of age have not been established.108 In addition, because of an association between oculotoxic/neurotoxic effects (e.g., optic neuritis, optic atrophy, subacute myelo-optic neuropathy [SMON]) and oral therapy with halogenated hydroxyquinoline derivatives (e.g., oral clioquinol at high dosages for prolonged periods)100,101,104,109,114,115,116,117,118,119,120,121,122,123,124,125 and the availability of effective alternative topical anti-infectives, use of iodoquinol in children currently is not recommended.104,114
Iodoquinol possesses amebicidal, antitrichomonal, and slight antibacterial and antifungal activity. It has been suggested that the 8-hydroxyquinolines function as antibacterial agents by chelating, at bacterial surfaces, trace metals essential for bacterial growth. Antieczematous and antiseborrheic properties have also been attributed to the hydroxyquinoline drugs.
Information on the percutaneous absorption of iodoquinol currently is not available.108 However, other halogenated hydroxyquinoline derivates (e.g., chlorquinaldol, clioquinol) have been shown to be absorbed systemically following topical application to the skin.100,101,102,103,104,105,106,107
Iodoquinol is a halogenated 8-hydroxyquinoline anti-infective agent that is closely related chemically and pharmacologically to iodochlorhydroxyquin. Iodoquinol contains about 64% iodine. The drug occurs as a light yellowish to tan, microcrystalline powder which is odorless or has a faint odor and is practically insoluble in water and sparingly soluble in alcohol.
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Topical | Cream | 1% with Hydrocortisone 1%* | Vytone® (with propylene glycol) |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
AHFS® Drug Information. © Copyright, 1959-2024, Selected Revisions May 10, 2024. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, MD 20814.
Only references cited for selected revisions after 1984 are available electronically.
100. Food and Drug Administration. Topical antifungal drug products for over-the-counter human use; establishment of a monograph. Advance notice of proposed rulemaking. [21 CFR Part 333] Fed Regist . 1982; 47:12480-566.
101. American Pharmaceutical Association. Handbook of nonprescription drugs. 9th ed. Washington, DC: American Pharmaceutical Association; 1990:983.
102. Ezzedeen FW, Stohs SJ, Kilzer KL et al. Percutaneous absorption and disposition of iodochlorhydroxyquin in dogs. J Pharm Sci . 1984; 73:1369-72. [PubMed 6239025]
103. Stohs SJ, Ezzedeen FW. Percutaneous absorption of iodochlorhydroxyquin in humans and dogs. Pediatrics . 1984; 73:880-1. [PubMed 6233531]
104. American Academy of Pediatrics Committee on Drugs. Clioquinol (iodochlorhydroxyquin, Vioform) and iodoquinal (diiodohydroxyquin): blindness and neuropathy. Pediatrics . 1990; 86:797-8. [PubMed 2146587]
105. Fischer T, Hartvig P. Skin absorption of 8-hydroxyquinolines. Lancet . 1977; 1:603. [PubMed 65689]
106. Fischer T, Fagerlund C, Hartvig P. Absorption of 8-hydroxyquinolines through the human skin. Acta Derm Venereol . 1978; 58:407-11. [PubMed 82350]
107. Stohs SJ, Ezzedeen FW, Anderson AK et al. Percutaneous absorption of iodochlorhydroxyquin in humans. J Invest Dermatol . 1984; 82:195-8. [PubMed 6229586]
108. Vytone® (iodoquinol and hydrocortisone) cream prescribing information. In: Barnhart ER, publisher. Physicians' desk reference. 45th ed. Oradell, NJ: Medical Economics Inc; 1991:893.
109. Yodoxin® (iodoquinol) tablets prescribing information. In: Barnhart ER, publisher. Physicians' desk reference. 45th ed. Oradell, NJ: Medical Economics Company Inc; 1991:1045.
110. Carpenter CL, Jolly HW, McCormick GE et al. Combined steroid-antiinfective topical therapy in common dermatoses: a double-blind, multi-center study of iodochlorhydroxyquin-hydrocortisone in 277 patients. Curr Ther Res . 1973; 15:650-9. [PubMed 4270829]
111. Fradkin JE, Wolff J. Iodide-induced thyrotoxicosis. Medicine (Baltimore) . 1983; 62:1-20. [PubMed 6218369]
112. Soesman-van Waadenoijen Kernekamp A, van Ketel WG. Persistence of patch test reactions to clioquinol (Vioform) and cross-sensitization. Contact Dermatitis . 1980; 6:455-60. [PubMed 6452247]
113. Hutzler D, Pevny I. [Allergies to 8-hydroxyquinoline derivatives.] (German; with English abstract.) Dermatosen Beruf Umwelt . 1988; 36:86-90.
114. American Academy of Pediatrics Committee on Drugs. Blindness and neuropathy from diiodohydroxyquin-like drugs. Pediatrics . 1974; 54:378-9. [PubMed 4278011]
115. Reich JA, Billson FA. Toxic optic neuritis: clioquinol ingestion in a child. Med J Aust . 1973; 2:593-5. [PubMed 4273528]
116. Ferrier TM, Eadie MJ. Clioquinol encephalopathy. Med J Aust . 1973; 2:1008-9. [PubMed 4272640]
117. Kosaka K, Shimada Y. SMON. JAMA . 1974; 228:566-7. [PubMed 4406178]
118. Oakley GP Jr. The neurotoxicity of the halogenated hydroxyquinolines: a commentary. JAMA . 1973; 225:395-7. [PubMed 4270059]
119. Nakae K. Yamamoto SI, Shigematsu I. Relation between subacute myelo-optic neuropathy (SMON) and clioquinol: nationwide survey. Lancet . 1973; 1:171-3. [PubMed 4118793]
120. Anon. Iodochlorhydroxyquin and travelers' diarrhea. FDA Drug Bull . 1972; 2:2.
121. Selby G. Subacute myelo-optic neuropathy in Australia. Lancet . 1972; 1:123-5. [PubMed 4108984]
122. Kean BH. Subacute myelo-optic neuropathy: a probable case in the United States. JAMA . 1972; 220:243-4. [PubMed 4258565]
123. Igata A. Halogenated oxyquinoline derivatives and neurological syndromes. Lancet . 1971; 2:42-3.
124. Nakae K, Yamamoto SI, Igata A. Subacute meylo-optico-neuropathy (SMON) in Japan. Lancet . 1971; 2:510-2. [PubMed 4105662]
125. Anon. Entero-Vioform and organic neurologic disease. Med Lett Drugs Ther . 1971; 13:51-2. [PubMed 4326942]
126. Upjohn AC, Galbraith HJ, Solomons B. Raised serum protein-bound iodine after topical clioquinol. Postgrad Med J . 1971; 47:515-6. [PubMed 4254353][PubMedCentral]
127. Caravati CM, Richardson DR, Wood BT. Topical iodochlorhydroxyquin—effect on thyroid function studies. Cutis . 1967; 5:447-50.