Antibiotics and Their Types, Uses and Side Effects

An antibiotic is a drug that kills or slows the growth of bacteria. Antibiotics are one class of antim
icrobials, a larger group which also includes anti-viral, anti-fungal, and anti-parasitic drugs. Antibiotics are ch
emicals produced by or derived from microorganisms (i.e. bugs or germs such as bacteria and fungi). The first antibiotic was discovered by Alexander Fleming in 1928 in a significant breakthrough for medical science. Antibiotics are among the most frequently prescribed medications in modern medicine.
Some antibiotics are 'bactericidal', meaning that they work by killing bacteria. Other antibiotics are'bacteriostatic', meaning that they work by stopping bacteria multiplying.
Each different type of antibiotic affects differentbacteria in different ways. For example, an antibiotic mightinhibit a bacterium's ability to turn glucose into energy, or its ability to construct its cell wall.
When this happens, the bacterium dies instead of reproducing.

PENICILLINS

	CEPHALOSPORINS	FLUOROQUINOLONES	AMINOGLYCOSIDES	MONOBACTAMS	CARBAPENEMS	MACROLIDES	OTHER
Natrual	First generation	Ciprofloxacin (Cipro) Levofloxacin (Levaguin) Moxifloxacin (Avelox) Norfloxacin	Amikacin Gentamicin Kanamycin Neomycin Tobramycin	Aztreonam	Ertapenem Imienem Meropenem	Azithromycin Clarithromycin Dirithromycin Erythromycin Clindamycin	Vancomycin Rifampin Doxycycline Linezolid Tetracycline Trimethoprim/ sulfamethoxacole
Penicillin G Penicillin-VK	Cephalothin Cefazolin (Ancef, Kefzol) Cephapririn Cephalexin (Keflex) other

Penicillinase Resistant

	Second Generation
Methicillin Nafcillin Oxacillin other	Cefacor Cefotetan (Cefotan) other
Aminopenicillins	Third Generation
Ampicillin	Ceftriaxone (Rocephin) other
	Fourth Generation
	Cefpirome Cefepime

Antibiotic Grouping By Mechanism

Cell Wall Synthesis	PenicillinsCephalosporins Vancomycin Beta-lactamase Inhibitors Carbapenems Aztreonam Polymycin Bacitracin
Protein Synthesis Inhibitors	Inhibit 30s Subunit Aminoglycosides (gentamicin) Tetracyclines Inhibit 50s Subunit Macrolides Chloramphenicol Clindamycin Linezolid Streptogramins
DNA Synthesis Inhibitors	Fluoroquinolones  Metronidazole
RNA synthesis Inhibitors	Rifampin
Mycolic Acid synthesis inhibitors	Isoniazid
Folic Acid synthesis inhibitors	Sulfonamides Trimethoprim

Antibiotic Classification & Indications

Inhibits Cell Wall Synthesis

Penicillins (bactericidal: blocks cross linking via competitive inhibition of the transpeptidase enzyme)
Class/Mechanism	Drugs	Indications (**Drug of Choice)	Toxicity
Penicillin	Penicillin G Aqueous penicillin G Procaine penicillin G Benzathine penicillin G Penicillin V	Strep. pyogenes (Grp.A)** Step. agalactiae (Grp.B)** C. perfringens(Bacilli)**	Hypersensitivity reaction Hemolytic anemia
Aminopenicillins	Ampicillin Amoxicillin	Above + ↑ Gram-negative: E. faecalis** E. Coli**	Above
Penicillinase-resistant-penicillins	Methicillin Nafcillin Oxacillin Cloxacillin Dicloxacillin	Above + PCNase-producingStaph. aureus	Above + Interstitial nephritis
Antipseudomonal penicillins	Carbenicillin Ticarcillin Piperacillin	Above + Pseudomonas aeruginosa**	Above
Cephalosporins (bactericidal: inhibits bacterial cell wall synthesis via competitive inhibition of the transpeptidase enzyme)
1st generation	Cefazolin Cephalexin	Staph. aureus** Staph. epidermidis** Some Gram-negatives: E. Coli Klebsiella	Allergic reaction Coombs-positive anemia (3%)
2nd generation	Cefoxitin Cefaclor Cefuroxime	Above + ↑ Gram-negative	Allergic Reaction ETOH Disulfiram reaction
3rd generation	Ceftriaxone Cefotaxime Ceftazidime Cefepime (4th generation)	Above + ↑ Gram-negative Pseudomonas	Allergic Reaction ETOH Disulfiram reaction

Other Cell Wall Inhibitors

Vancomycin  (bactericidal: disrupts peptioglycan cross-linkage)	Vancomycin	MRSA**PCN/Ceph allegies** S. aureus S. epidermidis	Red man syndrome Nephrotoxicity Ototoxicity
Beta-lactamase Inhibitors  (bactericidal: blocking cross linking)	Clavulanic Acid Sulbactam Tazobactam	S aureus**S epidermis**E.Coli** Klebsiella**	Hypersensitivity Reaction Hemolytic anemia
Carbapenems	Imipenem (+ cilastatin) Meropenem Doripenem Ertapenem	Broadest activity of any antibiotic (except MRSA, Mycoplasma)
Aztreonam	Aztreonam	Gram-negative rods Aerobes Hospital-acquired infections
Polymyxins	Polymyxin B Polymyxin E	Topical Gram-negative infections
Bacitracin	Bacitracin	Topical Gram-positive infections

Protein Synthesis Inhibition

Anti-30S ribosomal subunit
Aminoglycosides (bactericidal: irreversible binding to 30S)	Gentamicin Neomycin Amikacin Tobramycin Streptomycin	Aerobic Gram-negatives Enterobacteriaceae Pseudomonas	Nephrotoxicity Ototoxicity
Tetracyclines (bacteriostatic: blocks tRNA)	Tetracycline Doxycycline Minocycline Demeclocycline	RickettsiaMycoplasmaSpirochetes (Lyme's disease)	Hepatotoxicity Tooth discoloration Impaired growth Avoid in children < 12 years of age

Anti-50S ribosomal subunit

Macrolides(bacteriostatic: reversibly binds 50S)	Erythromycin Azithromycin Clarithromycin	Streptococcus H. influenzae Mycoplamsa pneumonia	Coumadin Interaction (cytochrome P450)
Chloramphenicol(bacteriostatic)	Chloramphenicol	H influenzae Bacterial Meningitis Brain absces	Aplastic Anemia Gray Baby Syndrome
Lincosamide (bacteriostatic: inhibits peptidyl transferase by interfering with amino acyl-tRNA complex)	Clindamycin	Bacteroides fragilis S aureus Coagulase-negative Staph & StrepExcellent Bone Penetration	Pseudomembranous colitis Hypersensitivity Reaction
Linezolid (variable)	Linezolid	Resistant Gram-positives
Streptogramins	Quinupristin Dalfopristin	VRE GAS and S. aureus skin infections

DNA Synthesis Inhibitors

Fluoroquinolones (bactericidal: inhibit DNA gyrase enzyme, inhibiting DNA synthesis)
1st generation	Nalidixic acid	Steptococcus MycoplasmaAerobic Gram +	PhototoxicityAchilles tendon rupture Impaired fracture healing
2nd generation	Ciprofloxacin Norfloxacin Enoxacin Ofloxacin Levofloxacin	As Above +Pseudomonas	as above
3rd generation	Gatifloxacin	As above + Gram-positives	as above
4th generation	Moxifloxacin Gemifloxacin	As above + Gram-positives + anaerobes	as above

Other DNA Inhibitors

 

Metronidazole (bacteridical: metabolic biproducts disrupt DNA)	Metronidazole (Flagyl)	Anaerobics	Seizures Crebelar dysfunction ETOH disulfram reaction
RNA Synthesis Inhibitors
Rifampin (bactericidal: inhibits RNA transcription by inhibiting RNA polymerase)	Rifampin	Staphylococcus Mycobacterium (TB)	Body fluid discoloration Hepatoxicity (with INH)
Mycolic Acids Synthesis Inhibitors
Isoniazid	Isoniazidz	TB Latent TB
Folic acid Synthesis Inhibitors
Trimethoprim/Sulfonamides(bacteriostatic: inhibition with PABA)	Trimethoprim/Sulfamethoxazole (SMX) Sulfisoxazole Sulfadiazine	UTI organisms Proteus Enterobacter	Thrombocytopenia Avoid in third trimester of pregnancy
Pyrimethamine	Pyrimethamine	Malaria T. gondii

Bacteria Overview

Gram Postive Cocci Staphylococcus Staph. aureus MSSA MRSA Staph. epidermis Staph saprophyticus Streptococcus Strep pneumoniae Strep pyogenes (Group A) Strep agalacticae (Group B) Strep viridans Strep Bovis (Group D) Enterococci E. faecalis (Group D strep) Gram Positive Bacilli Spore Forming Bacillus anthracis Bacillus cereus Clostridium tetani Clostridium botulinum Clostridium perfringens Clostridium difficile Non-Spore Forming Corynebacterium diphtheriae Listeria monocytogenes Gram Negative Cocci Neisseria Neisseria meningitidis Neisseria gonorrhoeae Gram Negative Bacilli Enterics Escherichia coli Salmonella typhi Salmonella enteridis Shigella dysenteriae Klebsiella pneumoniae Serratia Proteus Campylobacter jejuni Vibrio cholerae Vibrio parahaemolyticus/vulnificus Helicobacter pylori Pseudomonas aeruginosa Bacteroides fragilis Respiratory bacilli Haemophilus influenzae Haemophilius ducreyi Bordatella pertussis Zoonotic bacilli Yersinia enterocolitica Yersinia pestis Brucella Francisella tularensis Pasteurella multocida Bartonella henselae Other Gardnerella vaginalis Other Bacteria Mycobacteria Mycobacterium tuberculosis Mycobacterium leprae MOTTS Spirochetes Borrelia burgdorferi Leptospira interrogans Treponema pallidum Chlamydiaceae Chlamydia trachomatis Chlamydophila Rickettsia Ehrlichia Mycoplasmataceae Mycoplasma pneumoniae Ureaplasma urealyticum Fungus-like Bacteria Actinomyces israelii Nocardia