How should I write a prescription for chlorhexidine?

How to Prescribe Chlorhexidine

Prescribe chlorhexidine gluconate based on the specific clinical indication: 0.12% mouthwash for oral/dental antisepsis, 0.5% in 70% alcohol for skin antisepsis before central neuraxial blockade, or 2% in 70% alcohol for central venous catheter insertion and general surgical skin preparation. 1, 2

Formulation Selection by Clinical Use

For Oral/Dental Indications

• Prescribe 0.12% to 0.2% chlorhexidine gluconate mouthwash for short-term adjunctive management of gingivitis, post-oral surgical procedures, and when mechanical debridement is not possible 3, 4
• The standard formulation in the US is 0.12% chlorhexidine gluconate oral rinse, available by prescription only 5
• Instruct patients to rinse with 15 mL (approximately one tablespoon) twice daily for 30 seconds, then expectorate 5, 6
• Duration should typically be limited to 2-4 weeks to minimize side effects, particularly tooth staining 3, 4

For Skin Antisepsis Before Central Neuraxial Blockade

• Prescribe 0.5% chlorhexidine gluconate in 70% alcohol rather than 2% concentration for spinal or epidural procedures 1
• This lower concentration is preferred due to lack of antimicrobial superiority of 2% over 0.5%, combined with clear evidence of neurotoxicity risk with chlorhexidine 1
• The solution must be allowed to completely dry before skin puncture 1

For Central Venous Catheter Insertion and General Surgical Skin Prep

• Prescribe 2% chlorhexidine gluconate in 70% alcohol for central venous access device insertion and general surgical skin decontamination 1
• This higher concentration is appropriate when there is no risk of contact with neural tissue 1

For Neonatal Use

• In premature neonates >24 weeks gestational age, 2% chlorhexidine in 70% isopropyl alcohol can be used with careful monitoring for skin toxicity 7
• Use the minimum volume necessary while ensuring adequate antisepsis in infants under 2 months of age 1

Critical Safety Warnings to Include in Prescription Instructions

Absolute Contraindications (from FDA labeling)

• Do not use if allergic to chlorhexidine gluconate - can cause severe, potentially fatal anaphylactic reactions 2
• Never use as preoperative skin preparation on the head or face 2
• Never allow contact with meninges, brain tissue, middle/inner ear, or eyes 1, 2
• Do not use in the genital area 2

Application Precautions

• Keep away from eyes, ears, and mouth - can cause permanent eye injury and deafness if it enters these areas 1, 2
• For skin antisepsis, keep chlorhexidine bottles away from neuraxial procedure equipment to prevent accidental contamination of syringes 1
• Change gloves if contaminated with chlorhexidine before handling neuraxial procedure equipment 1
• Allow solution to dry completely before proceeding with invasive procedures 1

Common Side Effects to Counsel Patients About

For Oral Use

• Tooth, restoration, and tongue staining is the most common adverse effect, reported by 77% of dentists as a major patient concern 5, 6
• Bitter taste alteration occurs in approximately 12% of patients 5
• Less common effects include mouth dryness and oral ulcerations (6%) 5
• Advise patients to avoid using regular toothpaste immediately before or after chlorhexidine as anionic agents in toothpaste rapidly reduce chlorhexidine activity 6

For Skin Use

• Skin irritation is concentration-dependent, with 4% formulations most likely to cause dermatitis 1
• Allergic reactions are uncommon but can be severe 1

Prescription Writing Format

For Oral Rinse:

• Chlorhexidine gluconate 0.12% oral rinse
• Dispense: 473 mL (16 oz) bottle
• Sig: Rinse with 15 mL (½ oz) for 30 seconds twice daily after brushing. Expectorate. Do not swallow. Do not rinse mouth with water after use.
• Duration: 2-4 weeks maximum for initial course

For Skin Antisepsis (Neuraxial Procedures):

• Chlorhexidine gluconate 0.5% in 70% alcohol solution
• Dispense: Single-use applicators or appropriate volume
• Sig: Apply to skin and allow to dry completely before procedure. For external use only. Keep away from procedure equipment.

For Skin Antisepsis (Central Lines/Surgery):

• Chlorhexidine gluconate 2% in 70% alcohol solution
• Dispense: Single-use applicators (e.g., ChloraPrep) or 4 oz bottle
• Sig: Apply to skin and allow to dry completely before procedure. For external use only. 1, 2

Special Populations Requiring Chlorhexidine

Chlorhexidine is particularly indicated for:

• Developmentally disabled patients unable to perform adequate mechanical plaque removal 8
• Medically compromised patients with limited ability to maintain oral hygiene 8
• Dependent elderly populations 8
• Post-periodontal surgery patients (85% of dentists recommend) 5
• Acute gingivitis management (74% of dentists recommend) 5