Antiinfectives

Anti-infectives are agents used to prevent or treat infections caused by pathogenic microorganisms. The term encompasses antibiotics, antivirals, antifungals, and antiparasitics, and they may be used systemically or topically depending on the infection.

Antibiotics target bacteria and can be bactericidal or bacteriostatic. Mechanisms include inhibition of cell wall synthesis (beta-lactams, glycopeptides), disruption of protein synthesis (macrolides, tetracyclines, aminoglycosides), inhibition of nucleic acid synthesis (quinolones, rifamycins), and interference with essential metabolic pathways (sulfonamides). Antivirals inhibit viral replication by targeting viral enzymes or entry; antifungals disrupt fungal membranes or ergosterol synthesis; antiparasitics act on parasite metabolism or neuromuscular function to kill or arrest parasites.

Clinical use relies on infection site, causative organism, and susceptibility. Antimicrobial resistance is a major concern, driven by misuse and incomplete courses. Stewardship programs aim to optimize selection, dosing, duration, and de-escalation to preserve effectiveness. Adverse effects vary and can include allergic reactions, gastrointestinal symptoms, liver or kidney toxicity, and drug interactions.

History and context: the discovery of penicillin in 1928 revolutionized treatment of bacterial infections, followed by the development of many additional drug classes. Ongoing research seeks new agents and strategies to counter resistant pathogens and to reduce toxicity, with emphasis on appropriate indication, dosing, and duration to improve outcomes.