“If this blog helped you out, don’t keep it to yourself—share the link on your socials!” 👍 “Like what you read? Spread the love and share this blog on your social media.” 👍 “Found this useful? Hit share and let your friends know too!” 👍 “If you enjoyed this post, please share the URL with your friends online.” 👍 “Sharing is caring—drop this link on your social media if it helped you.”

Sunday, July 27, 2025

Chlorhexidine


Chlorhexidine is a broad-spectrum antiseptic and disinfectant used in both medical and dental practice. It is available in various formulations such as mouthwashes, skin cleansers, surgical scrubs, wound antiseptics, and catheter coatings. Chlorhexidine exhibits potent activity against a wide range of gram-positive and gram-negative bacteria, some fungi, and certain viruses, but is inactive against bacterial spores and non-enveloped viruses.

This comprehensive professional monograph outlines the classification, mechanism of action, clinical uses, dosages (by formulation), contraindications, adverse effects, precautions, and drug interactions of chlorhexidine.

Pharmacological Classification

  • Therapeutic class: Antiseptic, disinfectant, antimicrobial

  • Pharmacological class: Biguanide cationic antiseptic

  • ATC Codes:

    • D08AC02 (dermatological use)

    • A01AB03 (oral antiseptic)

    • R02AA05 (throat antiseptic)

    • G01AX09 (gynecological use)

Brand Names (Formulation Dependent)

  • Corsodyl® (mouthwash, dental gel – UK)

  • Hibitane®, Peridex®, PerioGard® (oral rinse)

  • Hibiscrub®, Hibiclens® (surgical scrub/hand wash)

  • Savlon®, Betasept® (antiseptic creams/solutions)

  • Chlorhexidine acetate/diacetate/digluconate – depending on region/form

Mechanism of Action

Chlorhexidine is a cationic polybiguanide that binds to the negatively charged surfaces of bacterial cell walls, causing membrane disruption, cytoplasmic leakage, and cell death.

  • At low concentrations: Bacteriostatic (inhibits growth)

  • At high concentrations: Bactericidal (kills bacteria)

  • Also acts on fungi, yeasts, and enveloped viruses

Its substantivity (persistent activity) is especially valuable in oral rinses, where it remains bound to oral mucosa and teeth for hours, continuing to exert antimicrobial effects.

Spectrum of Activity

Effective Against

  • Gram-positive bacteria (e.g., Staphylococcus aureus, Streptococcus spp.)

  • Gram-negative bacteria (e.g., Escherichia coli, Pseudomonas aeruginosa, Klebsiella spp. – moderately)

  • Candida albicans

  • Enveloped viruses (e.g., HSV, HIV, influenza)

Ineffective Against

  • Bacterial spores

  • Non-enveloped viruses (e.g., norovirus, enteroviruses)

  • Mycobacteria (limited)

Formulations and Clinical Uses

1. Oral Formulations

  • Mouthwash (0.1–0.2%)

    • Treats gingivitis, periodontitis, oral candidiasis, aphthous ulcers, mucositis

    • Used pre-procedure to reduce microbial load in dentistry

    • Dosage: Rinse with 10–15 mL for 30 seconds twice daily

    • Avoid food or drink for 30 minutes after use

  • Dental gel (0.2–1%)

    • Direct application for localized gingival inflammation, post-surgical healing

2. Skin/Surgical Formulations

  • Antiseptic solution (0.5–4%) for:

    • Preoperative skin preparation

    • Surgical hand scrub

    • Wound cleansing

    • Catheter site cleaning

  • Alcoholic chlorhexidine (2% chlorhexidine in 70% isopropyl alcohol)

    • Highly effective for surgical skin antisepsis and catheter insertion

3. Vaginal Formulations

  • Vaginal douches (0.05%) in bacterial vaginosis, pre-procedural cleansing

4. Urological Applications

  • Irrigation solution (0.02–0.05%)

    • Bladder irrigation in catheterized patients to reduce infection risk

5. Ear/Nasal

  • Otic use: Avoid due to risk of ototoxicity, especially if tympanic membrane is perforated

  • Nasal antisepsis (e.g., before MRSA decolonization): Rare and requires extreme caution

Dosage Guidelines (Formulation-Based)

  • Mouth rinse (0.2%): 10–15 mL, rinse for 30–60 seconds, twice daily

  • Surgical scrub (4%): Wash hands and forearms for 2–5 minutes

  • Skin prep (2%–4%): Apply and allow to dry before surgery

  • Wound irrigation (0.05%): Rinse or soak as directed

  • Catheter site disinfection: Clean with alcohol–chlorhexidine prep pad before insertion

Contraindications

  • Hypersensitivity to chlorhexidine or related compounds

  • Perforated tympanic membrane (topical otic use contraindicated)

  • Intrathecal or intravenous use – not permitted

  • Contact with brain, meninges, or middle ear – strictly avoided

Warnings and Precautions

  • Eye exposure: Can cause serious eye injury – avoid all ophthalmic contact

  • Allergic reactions: Reports of anaphylaxis, urticaria, bronchospasm, and contact dermatitis

  • Discoloration of teeth: Prolonged oral use may cause brown staining of teeth, tongue, and restorations

  • Taste disturbances: May cause temporary alteration in taste perception

  • Skin irritation: Especially in alcohol-based solutions

  • Flammability: Alcoholic chlorhexidine is flammable – must dry completely before use with diathermy

Adverse Effects

Common

  • Local irritation, erythema, burning, especially on broken skin

  • Tooth discoloration, tongue staining (with mouthwash)

  • Taste changes (metallic or bitter taste)

Uncommon

  • Contact dermatitis

  • Parotid gland swelling (rare, in oral use)

  • Dry mouth

Rare but Serious

  • Anaphylaxis (potentially life-threatening)

  • Eye injury: Corneal ulceration with accidental ophthalmic exposure

  • Ototoxicity: Hearing loss with middle/inner ear exposure

Drug Interactions

  • Incompatible with anionic surfactants, soaps, and toothpastes

    • Toothpaste use should be separated by 30–60 minutes from mouthwash to maintain efficacy

  • Iodine preparations: Can reduce effectiveness of both agents when used together

  • Alcohol-containing formulations: Risk of cumulative skin dryness and irritation when used with other topical alcohols

Use in Special Populations

Pregnancy

  • Generally considered safe in topical and oral applications

  • Oral rinses and skin preps are categorized as low risk

  • Avoid intravaginal or mucosal use unless prescribed

Lactation

  • No known harmful effects

  • Avoid application to breast or nipple area unless advised

Pediatrics

  • Safe for use in children over 6 years for oral rinses

  • Use in infants should be limited to diluted topical preparations

  • Not for routine diaper area use due to risk of irritation

Storage and Handling

  • Store at room temperature

  • Avoid direct sunlight

  • Flammable formulations (alcohol-based): Store away from ignition sources

  • Do not freeze or autoclave alcohol–chlorhexidine solutions

Clinical and Practical Notes

  • Highly effective in preoperative skin prep: superior to povidone-iodine in many studies for infection reduction

  • Chlorhexidine-coated catheters and dressings are used to reduce central line–associated bloodstream infections (CLABSIs)

  • In oral care, especially useful in managing plaque, gingivitis, and post-surgical healing

  • Its substantivity makes it long-lasting compared to other topical antiseptics

  • Not effective against spores – not suitable for sterilization of surgical instruments

Counseling Points

  • Do not swallow chlorhexidine oral products

  • Avoid using immediately after brushing teeth (wait at least 30 minutes)

  • Do not use in eyes, ears, or open CNS tissues

  • For mouthwash, expect transient taste changes and possible tooth staining with prolonged use

  • Stop use and seek medical advice if rash, swelling, or breathing difficulty occurs

  • Allow alcoholic skin preps to fully dry before using electrosurgical instruments




on
Labels:

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)