Chlorhexidine: Effect, Uses & Risks

Chlorhexidine is an antiseptic. It has wide-ranging antibacterial effects and is used primarily in dentistry.

What is chlorhexidine?

Chlorhexidine is an antiseptic. It has wide-ranging antibacterial effects and is used primarily in dentistry. Chlorhexidine belongs to the polyguanide group. It is an antibacterial agent. Since it does not dissolve well in water, it is not suitable as a rinsing solution. In commerce, it is usually offered as chloride or acetate. For medical applications, it is available mainly in the form of gluconate. In this state, it achieves the same effect as chlorhexidine. In neutral aqueous solution, the molecule has a double positive charge. It is play-gel symmetrical and has two benzene rings. The drug is highly soluble in organic solvents such as dichloromethane. For individual medical applications, it is available in the form of creams, gels, ointments or solutions. Drugs containing chlorhexidine are available over-the-counter in pharmacies.

Pharmacological action

Chlorhexidine possesses extensive antibacterial properties. Due to its positive charge, it attracts bacteria with their negative charge. It also adheres for a long time on the respective treated body area, so that it shows a persistent and sustained depot effect. The antiseptic effect occurs because the active ingredient inserts itself into the cell membranes of the bacteria, thereby destroying them. The details of the mechanism of action are currently still being researched. Resistance to the substance has not yet been identified in any pathogen species. The drug has a slight effect on enveloped viruses and no effect on non-enveloped viruses. It is not absorbed by the body through the mucous membranes. Chlorhexidine is excreted almost one hundred percent; metabolism does not occur.

Medical application and use

Chlorhexidine was originally used primarily skin infections. Today, it is used primarily in dentistry, including disinfection before and after surgery. For example, after insertion of a dental implant, follow-up care with the active ingredient reduces the risk of peri-implant inflammation. Furthermore, the drug is used in the treatment of bacterial gingivitis, periodontitis and bad breath. The concentration of the solutions used in dentistry is between 0.03 and 2 percent. For the prevention of caries, it is recommended to dab the teeth with an appropriate gel or to apply it with the help of a splint. The drug is also available as a varnish, which is applied to the teeth. Due to its long adhesion, it continuously releases the active ingredient for three to four months. Sprays, gels and chips are also available. The active ingredient is also used as an ingredient in mouth rinses as part of oral hygiene. Comparative studies with on the effect of antibacterial solutions show that these solutions are superior to other products. When cleaning dentures, it also proves advantageous to regularly place the dentures in a chlorhexidine digluconate solution at night with a certain time interval. This reduces the germs that cause denture-related inflammation of the mucous membranes. The active ingredient has further applications in the field of wound care. For example, plasters, ointments and healing powders containing the active ingredient are available for disinfection. Chlorhexidine is also used for bacterial throat infections.

Risks and side effects

Prolonged use of chlorhexidine may lead to few side effects. However, these phenomena prove to be completely reversible in most cases. Side effects may include: Impaired taste sensation, brownish plaque on teeth and in the oral cavity. In rare cases, delayed wound healing or desquamation of the epithelial layer occur. In case of long-term use of a mouth rinse containing chlorhexidine, it may be advisable to use it weekly alternating with another preparation to avoid the brownish deposits on teeth and tongue. Combined use with certain substances results in inactivation of the antiseptic. The use of sodium lauryl sulfate, for example, leads to loss of function.For this reason, the active ingredient should be taken at a large time interval after the use of toothpaste or mouth rinse containing sodium lauryl sulfate. Iodine and triclosan are also active ingredients that inactivate chlorhexidine.