What Are Anti-Infective Agents?
Anti-infective agents, also known as antimicrobials, are medicines that kill microorganisms or stop them from growing. These organisms may include bacteria, fungi, protozoa, or viruses. Anti-infectives can be microbicidal (kill microbes) or microbiostatic (stop their growth). Some antimicrobial chemicals like disinfectants are used only on non-living surfaces.
Classification of Anti-Infective Agents
Anti-infective drugs are grouped according to the type of organism they control or the part of the body they treat:
- Antifungal Agents: Amphotericin-B, Griseofulvin, Miconazole, Ketoconazole, Itraconazole, Fluconazole, Naftifine
- Urinary Tract Anti-Infectives: Norfloxacin, Ciprofloxacin, Ofloxacin, Moxifloxacin
- Anti-Tubercular Agents: Isoniazid, Ethambutol, PAS, Pyrazinamide, Rifampicin, Bedaquiline, Delamanid, Pretomanid
- Antiviral Agents: Amantadine, Idoxuridine, Acyclovir, Foscarnet, Zidovudine, Ribavirin, Remdesivir, Favipiravir
- Antimalarials: Quinine, Chloroquine, Primaquine, Mefloquine, Cycloguanil, Pyrimethamine, Artemisinin
- Sulfonamides: Sulfanilamide, Sulfadiazine, Sulfamethoxazole, Sulfacetamide, Mafenide, Cotrimoxazole, Dapsone
Antifungal Agents
Antifungal drugs control fungal infections that affect skin, nails, mucous membranes, or internal organs. They can be applied topically or given orally or by injection in severe conditions.
Classification of Antifungal Agents
- Antibiotics: Polyenes (Amphotericin B, Nystatin), Benzofuran (Griseofulvin)
- Antimetabolite: Flucytosine
- Azoles: Imidazoles (Clotrimazole, Miconazole, Ketoconazole), Triazoles (Fluconazole, Itraconazole)
- Allylamines: Terbinafine
- Other Topical Agents: Tolnaftate, Undecylenic acid, Ciclopirox, Sodium thiosulfate
Amphotericin B
Amphotericin B targets ergosterol in fungal cell membranes, forms pores, and causes leakage of vital contents, leading to cell death. It is used for serious fungal infections such as candidiasis, aspergillosis, and cryptococcal meningitis. Injection forms must be refrigerated and protected from light.
Griseofulvin
Griseofulvin is a fungistatic drug used for ringworm infections. It interferes with fungal cell division by disturbing the spindle fibers and binds to keratin in skin and nails. Tablets and suspensions are stored at room temperature.
Miconazole
Miconazole blocks ergosterol synthesis by inhibiting fungal enzymes. It is widely used topically for athlete’s foot, ringworm, and cutaneous candidiasis. Tablets and suppositories must be kept away from moisture and heat.
Ketoconazole
Ketoconazole inhibits ergosterol formation and affects membrane permeability. It is used for systemic fungal infections such as oral thrush and histoplasmosis. Cream formulations should not be exposed to high temperature.
Itraconazole
Itraconazole blocks ergosterol synthesis and treats fungal infections like histoplasmosis and aspergillosis. Capsules must be stored away from light at room temperature.
Fluconazole
Fluconazole inhibits ergosterol production and is used for cryptococcal meningitis, candidiasis, and superficial fungal infections. Oral suspensions remain stable at room temperature.
Naftifine
Naftifine inhibits sterol synthesis by blocking squalene epoxidase and is used topically for tinea infections. It should be stored at room temperature away from light.
Urinary Tract Anti-Infective Agents
These medicines treat urinary tract infections by stopping bacterial growth in the urinary system. They are mainly fluoroquinolones and nitrofuran derivatives.
Norfloxacin
Norfloxacin inhibits DNA gyrase and prevents bacterial multiplication. It treats UTIs, gonorrhea, and bacterial diarrhea. Tablets should be stored in airtight containers.
Ciprofloxacin
Ciprofloxacin blocks DNA gyrase and topoisomerase IV, stopping bacterial replication. It treats joint infections, gastroenteritis, UTIs, and respiratory infections. Tablets are stored at room temperature.
Ofloxacin
Ofloxacin interferes with bacterial DNA replication and is used for bronchitis, pneumonia, UTIs, and reproductive tract infections. Store at 15°C–25°C away from light.
Moxifloxacin
Moxifloxacin blocks DNA gyrase and topoisomerase IV and is used for sinusitis, pneumonia, and eye infections. Store solutions between 2°C and 25°C.
