Chlorquinaldol Advanced Drug Monograph

Chlorquinaldol Report

Name: Chlorquinaldol Name (English): Chlorquinaldol DrugBank ID: DB13306 Type: Small Molecule CAS Number: 72-80-0

Synonyms: 2-methyl-5,7-dichloro-8-hydroxyquinoline, 5,7-dichloro-2-methyl-8-hydroxyquinoline, 5,7-dichloro-2-methyl-8-quinolinol, 5,7-dichloro-8-hydroxy-2-methylquinoline, 5,7-dichloro-8-hydroxyquinaldine, 5,7-dichloro-8-quinaldinol, Chlorchinaldol, Chlorquinaldolum, Chloquinan, Chlorchinaldin, Chlorguinaldon, Chloroquinaldol, Florabina, Gyno-Sterosan, Hydroxydichloroquinaldine, Intensol, Saprosan, Siogen, Siogenal, Siogene, Siogeno, Siogenon, Siosept, Siosteran, Sterosan, Steroxin, Sterozan, Vagisteran, 5,7-dichloro-2-methylquinolin-8-ol.

Pharmacology:

• Indication: Historically used as a topical antiseptic agent for skin infections. Currently used in European countries as a combination vaginal tablet with promestriene for the treatment of vaginal infections. Also used for skin, gastrointestinal, and vaginal infections with fungi, protozoa, and certain bacteria. Used in combination to treat vaginal atrophy with infection and for symptomatic treatment of allergic skin manifestations, and prophylaxis and treatment of mycotic skin infection (in combination with difluocortolone).
• Mechanism of Action: Bactericidal against both gram-positive and gram-negative bacteria, more effective against gram-positive bacteria, particularly staphylococci. The exact mechanism of its bactericidal effect is unknown, but 8-hydroxyquinolines are known to be bidentate chelators of several metal ions which act as critical enzyme cofactors. Does not appear to rely on chelation as the primary mechanism. Disrupts the cell membranes of bacteria and fungi and may interfere with their DNA replication processes. Exhibits anti-inflammatory properties.
• Pharmacodynamics: Bactericidal effect against various microorganisms.
• Absorption: Variable absorption (4.2 to 23.5%) after topical application. Oral absorption is reported to be 67.6%.
• Metabolism: Primarily metabolized (98%) to the sulfate form.
• Route of Elimination: Primarily excreted in the urine as the sulfate form (about 2% as the parent drug).

Chemical and Physical Properties:

• Molecular Formula: $\text{C}_{10}\text{H}_7\text{Cl}_2\text{NO}$
• Molecular Weight: 228.07 g/mol
• Melting Point: 108-112 °C

Hazards Identification:

• Harmful if swallowed.
• Causes skin irritation.
• May cause an allergic skin reaction.
• Causes serious eye irritation.
• May cause respiratory irritation.
• Very toxic to aquatic life with long-lasting effects.

Therapeutic Categories: Anti-Infective Agents, Local; Antiseptics and Disinfectants; Antiprotozoals; Dermatologicals; Genito Urinary System and Sex Hormones; Antiparasitic Products, Insecticides and Repellents.

ATC Codes: D08AH02, G01AC03, P01AA04, R02AA11.

Contraindications: Known hypersensitivity to chlorquinaldol or any of its components. Not generally recommended for use in pregnant or breastfeeding women unless the potential benefits justify the risks. Caution advised in children without medical supervision.

Side Effects:

• Common: Local skin reactions (redness, itching, burning at the application site), photosensitivity, gastrointestinal issues (nausea, vomiting, diarrhea).
• Rare: Allergic reactions (rash, hives, swelling, difficulty breathing), systemic side effects (dizziness, headache, fatigue), vaginal irritation (with vaginal application), microbial resistance with overuse.

Drug Interactions: May interact with other topical medications or antimicrobial agents.

Note: Chlorquinaldol was historically marketed under the trade name Sterosan. Clinical trials for bacterial vaginosis treatment have been terminated.