💊 Antibiotics: All Generations Explained — 1st to 4th (with Salt Names)

How antibiotics are organised: by chemical class (penicillins, cephalosporins, macrolides, tetracyclines, fluoroquinolones, aminoglycosides) and, for cephalosporins, by "generation" — each generation covers more bacteria (especially gram-negative) but can lose activity against others.

Cephalosporins — 1st generation: good against gram-positive skin/surgical bacteria. Salts: Cephalexin (oral), Cefazolin (IV). Used: skin infections, surgical prophylaxis, cellulitis.

Cephalosporins — 2nd generation: adds some gram-negative coverage. Salts: Cefuroxime, Cefaclor, Cefoxitin. Used: respiratory infections, sinusitis, mixed abdominal/gynecologic infections.

Cephalosporins — 3rd generation: broad gram-negative power; crosses into CSF (brain). Salts: Ceftriaxone (the famous once-daily IV), Cefotaxime, Ceftazidime, oral Cefixime. Used: pneumonia, meningitis, typhoid, gonorrhoea, pyelonephritis.

Cephalosporins — 4th generation: broadest balance, including Pseudomonas. Salts: Cefepime (IV). Used: hospital-acquired infections, febrile neutropenia, severe sepsis.

Penicillins: the original class. Salts: Amoxicillin (oral workhorse), Ampicillin, Penicillin V, Piperacillin (anti-Pseudomonas, with tazobactam), Amoxicillin-clavulanate (Augmentin — clavulanate defeats resistant bacteria). Used: strep throat, ear infections, pneumonia, dental infections.

Macrolides: Salts: Azithromycin (short-course), Clarithromycin, Erythromycin. Used: respiratory infections, whooping cough, atypical pneumonia — a penicillin-allergy alternative.

Tetracyclines: Salts: Doxycycline, Minocycline, Tetracycline. Used: acne, Lyme disease, chlamydia, rickettsial infections. NOT for children under 8 or pregnant women (teeth staining).

Fluoroquinolones: Salts: Ciprofloxacin, Levofloxacin, Moxifloxacin. Used: urinary tract infections, typhoid, some pneumonias. Reserve for when nothing else works (tendon/nerve side effects).

Aminoglycosides: Salts: Gentamicin, Amikacin. IV only; powerful against gram-negatives and sepsis; kidney/ear monitoring needed.

The universal rules: antibiotics kill BACTERIA only (never viruses); take exactly as prescribed; finish the course; never share; report allergy history (penicillin allergy is common and important). Resistance is the enemy — every unnecessary course is a training session for superbugs.

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