Penicillins Low toxicity Effective derivatives created from manipulating drug’s basic molecular structure Kills bacteria by preventing them from forming the rigid cell wall Because human cells do not have cell walls, they are not affected
Therapeutic Uses of Penicillins Abscesses Beta-hemolytic streptococcus Meningitis Otitis media Pneumonia Respiratory infections Tooth and gum infections Venereal diseases (syphilis and gonorrhea) Endocarditis due to streptococci
Penicillins’ Side Effects Diarrhea Allergies in 7% to 10% of populationPenicillins’ Dispensing Issues Take on an empty stomach Food slows absorption Acids in fruit juices or colas could deactivate the drug
b-Lactam Antibiotics Penicillin Penicilinase-resistant penicillins Penicillins + b- lactamase inhibitors Carbapenems Substitute a C for a S, add a double bond Monobactam Single ring
Inhibitors of Cell Wall Synthesis Cephalosporins First-generation: Narrow spectrum, gram- positive Second-generation: Extended spectrum includes gram-negative Third-generation: Includes pseudomonads; injected Fourth-generation: Oral
First-generation Similar to penicillinase-resistant penicillins with greater gram-negative coverage Used for community-acquired infections mild to moderate infections Second-generation Increased activity, especially against Haemophilus influenzae Used for Otitis media in children Respiratory infections UTIs Third-generation Active against a wide spectrum of gram-negative organisms Long half-life, so once-a-day dosing for some Used for Ambulatory patients Children (dosing before or after school)
Inhibitors of Cell Wall Synthesis Polypeptide antibiotics Bacitracin Topical application Against gram-positives Vancomycin Glycopeptide Important "last line" against antibiotic-resistant S. aureus
Quinolones Strong, rapid bactericidal action against most gram- negative and many gram-positive bacteria Antagonize the enzyme responsible for coiling and replicating DNA, causing DNA breakage and cell deathQuinolones’ Dispensing Issues Not to be given with theophylline Antacids interfere with absorption Avoid exposure to sun
Therapeutic Uses of Quinolones Bone and joint infections caused by gram-negative organisms Infectious diarrhea Ophthalmic infections Some sexually transmitted diseases Upper respiratory infections UTIs
Quinolones’ Side Effects Primarily gastrointestinal, with nausea and vomiting Dizziness Unpleasant taste Can cause joint problems such as swelling and malformations Patients taking them have a tendency to injure tendons
Rifamycin any of a family of antibiotics biosynthesized by a strain of Streptomyces mediterranei, effective against a broad spectrum of bacteria, including gram-positive cocci, some gram-negative bacilli, and Mycobacterium tuberculosis and certain other mycobacteria; used for the treatment of tuberculosis and the prophylaxis of meningococcal infections.
prophylaxis refers to medical or public healthmeasures taken in order to prevent disease or healthproblems, rather than to treat or cure an existingcondition. Prophylaxis is also a way to stem anoutbreak of disease, or minimize the symptoms ofsomeone who has been exposed to a disease or virus.