Difference Between Antibiotic and Antiseptic

Both, antibiotics and antiseptics, are chemical substances that prevent the growth and development of the microorganisms, but antibiotics are effective only against bacteria while antiseptic acts against a wide range of microorganisms. These two terms are confusing since they share some similar characteristics, but they do differ in many ways.


As mentioned above, antibiotics are chemical substances that kill and stop the growth of bacteria. They act by interfering with the cell wall synthesis and nucleic acid metabolism, and by inhibiting protein synthesis.

They are broadly classified as bacteriostatic, which acts primarily by inhibiting bacterial multiplication, and bactericidal, which acts primarily by killing the bacteria. However, this is being used less frequently in the current clinical practice, since most bacteriostatic drugs were shown to be bactericidal at high concentrations.

Before starting the antibiotic therapy, it should be based on the likely organisms involved, prevalence of the resistance of the organism, relevant pharmacology, presence of allergy or host factors that may modify pharmacology, degree of severity, urgency, and the availability of the culture and sensitivity results. To be an ideal antibiotic, it should be cheaper, freely available with a good compliance of the patient, availability of the oral forms, least toxic, and having fewer side effects.

Antibiotics are used to deal with systemic infections, post-operative infections, and during surgical procedures. The administration of the antibiotics are oral, while intravenous and intramuscular routes are used in the case of severe infections, septicemia and in instances where the gastro intestinal system is compromised so that the absorption is poor.

Adverse effects of the antibiotics vary depending on the category they belong, and range from mild to severe anaphylactic shock.


Antiseptic prevents the growth and development of the microorganisms without necessarily killing them. They can be topical agents that are used to apply the skin, mucus membranes and intimate objects or can be internally used agents such as urinary tract antiseptics.

Because of its anti-infective effect, they are widely used in cleaning of skin and wound surfaces, preparation of skin prior to surgical procedures, for good oral hygiene, disinfection of intimate objects including furniture and instruments.

Commonly used antiseptic agents are alcohol, hydrogen peroxide, iodine compounds, chlorhexidine, and mercury compounds. As they have different degrees of safety, they are being used for different purposes. For example, chlorhexidine, as it shows a high level of safety, is used in the mucous membranes, and most of the oral preparations are based on this.

Dosage of the antiseptic varies with the intended use and the type of product. Adverse effects may include hypersensitivity reactions, skin dryness, irritation, and systemic toxicity.


What is the difference between Antibiotics and Antiseptic?

• Antibacterial acts against bacteria while antiseptics are effective against a wide variety of microorganisms.

• Antibiotics kill and stop the growth of bacteria while antiseptic prevents the growth and development of the microorganisms without necessarily killing them.

• Antibiotics are used internally as well as externally, but antiseptics most often used externally.