Pharmacology of Chlorhexidine


Indication For reduction of pocket depth in patients with adult periodontitis, used as an adjunct to scaling and root planing procedures. Also for prevention of dental caries, oropharyngeal decontamination in critically ill patients, hand hygiene in health-care personnel, general skin cleanser, and catheter site preparation and care.
Pharmacodynamics Chlorhexidine, a topical antimicrobial agent, is bactericidal. Because of its positive charge, the chlorhexidine molecule reacts with the microbial cell surface to destroy the integrity of the cell membrane. This novel mechanism of action makes it highly unlikely for the development of bacterial resistance.
Mechanism of action Chlorhexidine's antimicrobial effects are associated with the attractions between chlorhexidine (cation) and negatively charged bacterial cells. After chlorhexidine is absorpted onto the organism's cell wall, it disrupts the integrity of the cell membrane and causes the leakage of intracellular components of the organisms.
Absorption Absorption of chlorhexidine from the gastrointestinal tract is very poor. Additionally, an in vivo study in 18 adult patients found no detectable plasma or urine chlorhexidine concentrations following insertion of four periodontal implants under clinical conditions.
Volume of distribution Not Available
Protein binding 87%
Metabolism Not Available
Route of elimination Excretion of chlorhexidine gluconate occurred primarily through the feces (~90%). Less than 1% of the chlorhexidine gluconate ingested by these subjects was excreted in the urine.
Half life Not Available
Clearance Not Available
Toxicity LD50= 2g/kg (human, oral); LD50= 3 g/kg (rat, oral); LD50= 2.5 g/kg (mice, oral); LD50= 21 mg/kg (male rat, IV); LD50= 23 mg/kg (female rat, IV); LD50= 25 mg/kg (male mice, IV); LD50= 24 mg/kg (female mice, IV); LD50= 1g/kg (rat, subcutaneous); LD50= 637 mg/kg (male mice, subcutaneous); LD50= 632 mg/kg (female mice, subcutaneous)
Affected organisms
  • Bacteria