Antibiotics: Types, Mechanisms, and Resistance

What are Antibiotics?

• Antibiotics are medicines that inhibit or kill the growth of microorganisms, such as bacteria, fungi, and parasites.
• They are used to treat bacterial infections, not viral infections.

Types of Antibiotics

• Bactericidal: Kill bacteria directly, e.g. penicillin and ampicillin.
• Bacteriostatic: Inhibit bacterial growth, e.g. tetracycline and erythromycin.
• Broad-spectrum: Effective against a wide range of bacteria, e.g. amoxicillin and ciprofloxacin.
• Narrow-spectrum: Effective against a specific type of bacteria, e.g. vancomycin and metronidazole.

Mechanisms of Action

• Interference with cell wall formation: Beta-lactam antibiotics, such as penicillin, inhibit the synthesis of the bacterial cell wall.
• Inhibition of protein synthesis: Antibiotics like tetracycline and erythromycin bind to the bacterial ribosome, preventing protein synthesis.
• Inhibition of DNA replication: Antibiotics like ciprofloxacin inhibit the replication of bacterial DNA.

Antibiotic Resistance

• Definition: The ability of bacteria to resist the effects of antibiotics.
• Causes: Overuse and misuse of antibiotics, genetic mutation, and transfer of resistant genes between bacteria.
• Consequences: Reduced effectiveness of antibiotics, increased risk of infection, and increased healthcare costs.

Antibiotic Use and Misuse

• Appropriate use: Use antibiotics only when necessary, as prescribed by a healthcare professional, and complete the full course of treatment.
• Inappropriate use: Using antibiotics for viral infections, not completing the full course of treatment, and sharing antibiotics with others.

Side Effects and Allergic Reactions

• Common side effects: Diarrhea, nausea, vomiting, and allergic reactions.
• Allergic reactions: Rashes, hives, and anaphylaxis (a severe, life-threatening reaction).
• Special considerations: Pregnant women, children, and people with certain medical conditions may require alternative antibiotics or special precautions.