REMIDIN

Indications

• Oral hygiene
• Skin antisepsis
• Bladder irrigation
• Urological surgery
• Management of infections associated with indwelling urinary catheters

Mechanism of action

Chlorhexidine's antimicrobial effects arise from its ability to disrupt microbial cell membranes. The positively charged chlorhexidine molecule interacts with negatively charged phosphate groups on microbial surfaces, compromising cell integrity and causing leakage of intracellular materials. This interaction allows chlorhexidine to enter the cell, precipitate cytoplasmic components, and ultimately induce cell death. At lower concentrations, chlorhexidine acts as a bacteriostatic agent, causing leakage of substances like potassium and phosphorus, while at higher concentrations, it exerts bactericidal effects.

Pharmacodynamics

Chlorhexidine exhibits broad-spectrum antimicrobial activity, effective against a variety of bacteria, yeasts, and viruses. Its action is dose-dependent, with lower concentrations (0.02%-0.06%) providing bacteriostatic effects, while higher concentrations (>0.12%) are bactericidal. Pharmacokinetic studies indicate that about 30% of chlorhexidine remains in the mouth after rinsing, allowing for slow release into oral fluids. This property, known as 'substantivity', helps prevent microbial colonization on surfaces like dentine, although prolonged use can lead to staining of oral surfaces.

Pharmacokinetics

Chlorhexidine is retained in the oral cavity at approximately 30% following rinsing, with a slow release into saliva. The pharmacokinetics of chlorhexidine indicate a high affinity for binding to tissues, which prolongs its antimicrobial action. The systemic absorption of chlorhexidine is minimal when used topically or as a rinse, making it safe for localized use. The elimination half-life and metabolism details are not well documented due to its primarily topical application.

Adverse effects

• Mucosal irritation
• Burning sensation
• Staining of teeth and oral surfaces
• Allergic reactions

Precautions

• Use with caution in patients with a history of hypersensitivity to chlorhexidine
• May cause irritation; discontinue if severe irritation occurs
• Staining may occur with prolonged use, particularly with oral formulations

Pregnancy

Chlorhexidine is generally considered safe for use during pregnancy; however, caution is advised and pregnant individuals should consult healthcare providers.

Breast-feeding

Chlorhexidine is considered safe during breastfeeding, but it is advisable to consult a healthcare provider.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Irrigation solution (0.02% and 0.05%)
• Capsules (various strengths)
• Catheter maintenance solution (1:5000)
• Topical solutions for oral hygiene

Indications

• Oral hygiene
• Halitosis (bad breath)
• Gingivitis
• Plaque control
• Postoperative oral care

Dosage

Children: Refer to BNF for Children for specific pediatric dosing recommendations.

Adults: Use as directed on the product label. Usually involves rinsing with 15-30 ml for 30 seconds to 1 minute, typically twice daily.

Mechanism of action

The exact mechanism of action of mouthwash is not fully understood, but it is attributed to the denaturing of lipoprotein complexes and possibly other actions. Evidence suggests that the major site of action may be the cell membrane, where agents can alter permeability, allowing the escape of enzymes, coenzymes, and metabolic intermediates. Additionally, cationic surfactants found in mouthwash can emulsify sebaceous material, facilitating the removal of dirt and bacteria. The mild desquamating effect of quaternary ammonium compounds in mouthwash aids in cleaning the oral cavity.

Pharmacodynamics

Mouthwash works by reducing the microbial load in the oral cavity and promoting a healthier environment. It can help to control plaque formation, reduce gingivitis, and provide symptomatic relief from oral conditions. The antibacterial properties of quaternary ammonium compounds contribute to the overall effectiveness in maintaining oral hygiene.

Pharmacokinetics

Mouthwash is typically used topically in the oral cavity, and its pharmacokinetics may vary based on the specific formulation. Generally, the active ingredients exert their effects locally, with minimal systemic absorption. The duration of action can depend on the formulation, frequency of use, and individual oral hygiene practices.

Pregnancy

There is limited data on the use of mouthwash during pregnancy. Consult a healthcare professional before use.

Breast-feeding

Consult a healthcare professional before use during breastfeeding, as safety has not been established.

Storage

Store in a cool, dry place, away from direct sunlight. Keep out of reach of children.

Formulations

• Liquid mouthwash
• Concentrated mouthwash

Mechanism of action

Chlorhexidine’s broad-spectrum antimicrobial effects are due to its ability to disrupt microbial cell membranes. The positively charged chlorhexidine molecule reacts with negatively charged phosphate groups on microbial cell surfaces - this reaction both destroys the integrity of the cell, allowing leakage of intracellular material, and allows chlorhexidine to enter the cell, causing precipitation of cytoplasmic components and ultimately cell death. The specific means of cell death is dependent on the concentration of chlorhexidine - lower concentrations are bacteriostatic and result in leakage of intracellular substances such as potassium and phosphorous, whereas higher concentrations are bactericidal and cause cytoplasmic precipitation.

Pharmacodynamics

Chlorhexidine is a broad-spectrum antimicrobial with demonstrated activity against both gram-positive and gram-negative bacteria, yeasts, and viruses. Antimicrobial activity is dose-dependent - chlorhexidine is bacteriostatic at lower concentrations (0.02%-0.06%) and bactericidal at higher concentrations (>0.12%). Pharmacokinetic studies of oral chlorhexidine rinses indicate that approximately 30% of the active ingredient is retained in the mouth following rinsing, which is subsequently slowly released into oral fluids. This ability to adsorb to dentine, shared with tetracycline antibiotics such as [doxycycline], is known as "substantivity" and is the result of chlorhexidine's positive charge - it is likely that this substantivity plays at least some role in chlorhexidine's antimicrobial activity, as its persistence on surfaces such as dentine prevent microbial colonization. Dental chlorhexidine rinses may result in staining of oral surfaces, such as teeth. This effect is not ubiquitous and appears to be more significant with extended therapy (i.e. up to 6 months) - nevertheless, patients for whom oral staining is unacceptable should use chlorhexidine rinse with caution and for the shortest effective interval. Allergic reactions to chlorhexidine have been associated with the development of anaphylaxis.

Mechanism of action

MODE OF ACTION ... NOT YET FULLY UNDERSTOOD BUT HAS BEEN ASCRIBED TO ... THE DENATURING OF LIPOPROTEIN COMPLEXES, & POSSIBLY OTHER ACTIONS. /QUATERNARY AMMONIUM COMPD/ EVIDENCE HAS BEEN PRESENTED THAT THE MAJOR SITE OF ACTION ... MAY BE THE CELL MEMBRANE, WHERE THE AGENTS MAY CAUSE CHANGES IN PERMEABILITY THAT PERMIT ESCAPE OF ENZYMES, COENZYMES, & METABOLIC INTERMEDIATES. /CATIONIC SURFACTANTS/ EMULSIFY SEBACEOUS MATERIAL, WHICH IS THEN REMOVED TOGETHER WITH DIRT & BACTERIA. THE MILD DESQUAMATING EFFECT OF THE QUATERNARY AMMONIUM COMPOUNDS AIDS IN CLEANING. /QUATERNARY AMMONIUM COMPD/