Chlorhexidine

BRAND NAMES

Chlorhexidine is sold under various brand names, including Corsodyl, Savlon, Hibiclens, Peridex, and PerioGard. The specific brand name typically depends on the product’s intended application such as an oral rinse or a skin antiseptic and the region in which it is distributed.

Examples include:

• For oral use: Corsodyl, Peridex, PerioGard

• For topical skin use: Hibiclens, Betasept, ChloraPrep One-Step

• Other formulations: Savlon, Dermol, Covonia, and Germolene also contain chlorhexidine.

MECHANISM OF ACTION

Chlorhexidine’s broad-spectrum antimicrobial activity stems from its ability to disrupt microbial cell membranes. The positively charged chlorhexidine molecule interacts with negatively charged phosphate groups on the microbial cell surface, compromising membrane integrity and causing leakage of intracellular contents. This interaction also allows chlorhexidine to penetrate the cell, leading to the precipitation of cytoplasmic materials and eventual cell death. The mechanism of action depends on the concentration—at lower levels, chlorhexidine is bacteriostatic, causing the leakage of substances like potassium and phosphorus, while at higher concentrations, it becomes bactericidal, leading to cytoplasmic precipitation and cell destruction.

PHARMACOKINETICS:

Absorption

Topical chlorhexidine shows minimal systemic absorption, while oral forms are very poorly absorbed from the gastrointestinal tract. After a 300 mg oral dose, peak plasma concentration (Cmax) reached only 0.206 µg/g at about 30 minutes (Tmax). In patients given four PerioChips, chlorhexidine was undetectable in both plasma and urine.

Distribution

Chlorhexidine is available worldwide in multiple formulations—such as solutions, gels, sprays, and chips—and is widely used for medical and personal care purposes, including skin antisepsis, oral hygiene, and wound management.

Metabolism

Because chlorhexidine is minimally absorbed from the gastrointestinal tract, it is unlikely to undergo significant metabolic conversion.

Excretion

Chlorhexidine is mainly eliminated via the feces, with about 90% of an ingested dose excreted through this route. Less than 1% is excreted in the urine due to its poor gastrointestinal absorption.

PHARMACODYNAMICS

Chlorhexidine is a broad-spectrum antimicrobial effective against Gram-positive and Gram-negative bacteria, yeasts, and viruses. Its antimicrobial effect is concentration-dependent: it is bacteriostatic at lower concentrations (0.02%-0.06%) and bactericidal at higher concentrations (>0.12%). Studies of oral rinses show that around 30% of chlorhexidine remains in the mouth after rinsing and is gradually released into oral fluids. This ability to bind to dentine—a property known as "substantivity," also seen with tetracyclines like doxycycline—is due to chlorhexidine’s positive charge and likely contributes to its antimicrobial effectiveness by preventing microbial colonization on oral surfaces.

ADMINISTRATION

The way chlorhexidine is administered can differ widely based on its formulation and the area being treated, such as for dental use or topical application on the skin. It is important to follow the instructions provided by a doctor, dentist, or pharmacist.

DOSAGE AND STRENGTH

While some medications must never be taken together, there are situations where two different medicines can be used concurrently even if an interaction is possible. In such cases, your doctor may adjust the dosage or take other precautions. Always inform your healthcare professional about any prescription or over-the-counter (OTC) medications you are currently taking.

DRUG INTERACTIONS

Chlorhexidine is available in different formulations, and its dosage and strength depend on the intended use. For oral rinses, it is commonly available as a 0.12% or 0.2% solution, typically used as 10–15 mL rinsed in the mouth for 30 seconds twice daily. For topical skin applications, chlorhexidine solutions or scrubs usually range from 2% to 4% and are applied directly to the skin, often before surgery or for wound care, taking care to avoid eyes, ears, or mucous membranes. Surgical scrubs generally use a 4% solution applied for 2–5 minutes for hand or skin antisepsis. Dosage may vary depending on age, condition, and formulation, so it is essential to follow the instructions provided by a healthcare professional or the product label.

FOOD INTERACTIONS

The main “food interactions” with chlorhexidine are related to its effects on the teeth and taste rather than metabolic interactions with food. Because chlorhexidine oral rinse is not swallowed, it does not affect the digestive system or interact with foods like oral medications do. Timing of eating and drinking: To ensure maximum effectiveness, avoid eating, drinking, or rinsing your mouth with water for at least 30 to 60 minutes after using the rinse. Additionally, to prevent changes in taste during meals, it is best to use the rinse after finishing eating.

CONTRAINDICATIONS

The most important contraindication for chlorhexidine is a known hypersensitivity or allergy to the substance, as reactions can be severe and even life-threatening, including anaphylaxis. Other contraindications and precautions depend on the specific product and its intended use, such as for oral care or topical skin application. General contraindications include: a history of allergic reactions to chlorhexidine or any of its ingredients, which requires complete avoidance, and the presence of serious or extensive skin wounds, since some topical formulations are not suitable for deep or open wounds due to the risk of increased systemic absorption.

SIDE EFFECTS

More common side effects:

• Altered taste

• Increased tartar (calculus) buildup on teeth

• Staining of teeth, mouth, dental fillings, dentures, or other oral appliances

Less common or rare side effects:

• Mouth irritation

• Swelling of glands on the sides of the face or neck

• Irritation at the tip of the tongue

OVER DOSE

An overdose of chlorhexidine is rare, as it is mainly used topically or as an oral rinse and is not intended to be swallowed. Accidental ingestion or excessive use can lead to symptoms such as:

• Nausea or vomiting

• Mouth, throat, or gastrointestinal irritation

• Abdominal pain

• Diarrhea

TOXICITY

Chlorhexidine has low systemic toxicity when used topically or as a mouthwash, but can be severely toxic if swallowed in high concentrations, introduced into the ear canal, or injected intravenously. The risk of toxicity is highly dependent on concentration, method of exposure, and individual sensitivity.