Antibiotics Ch 37

Definition Medications to treat bacterial infections Ideally, culture of suspect area should be done BEFORE starting antibiotic

Classifications Sulfonamides Penicillins Cephalosporins Tetracyclines Macrolides Aminoglycosides Quinolones

Uses Treatment of exisiting infection Prevention of infection

Responses Therapeutic – decrease in s/s of infection Subtherapeutic – s/s of infection do not improve Superinfection Antibiotic resistance Allergic reactions

Actions Bactericidal = kill bacteria Bacteriostatic – slow or interfere with growth of bacteria

Sulfonamides Bacteriostatic Treat: utis Pneumocystis carinii pneumonia (PCP) URIs Otitis media Often in combinatiion Bactrim, Septra, Pediazole, Gantrisin

Sulfonamide Side Effects Anemia, thrombocytopenia Photosensitivity Avoid tanning beds Avoid sunlight N-V-D uriticaria

Penicillins Natural Penicilllin G Penicillin V Aminopenicillins Amoxicillin Ampicillin Penicillinase-resistant Oxacillin Nafcillin

PCN Adverse Effects Allergy Rash, swelling, itching

Cephalosporins Semisynthetic Related to penicillin Bactericidal 4 generations

Cephalosporin Uses Surgical prophylaxis URIs Otitis media

Cephalosporin Examples Ancef Kefzol Mefoxin Ceftin Rocephin – also used to tx meningitis

Cephalosporin Side Effects Similar to PCN

Macrolides Erythromycin Zithromax Biaxin

Macrolide Uses Strep infections Mild-to-moderate URIs Lyme disease STDs

Macrolide Side Effects GI N-V-D Hepatotoxicity Flatulence anorexia

Tetracyclines Tetracycline Vibramycin Minocycline Bacteriostatic action

Tetracycline Uses Syphilis Lyme disease Pleural & pericardial effusions

Tetracyclines Effectiveness reduced by Dairy products Antacids Iron Will discolor teeth May slow fetal skeletal development

Tetracycline Side Effects N-V-D Superinfection Pseudomembranous colitis

Aminoglycosides Gentamicin Kanamycin Neomycin Streptomycin amikin

Aminoglycosides Poor oral absorption No oral forms, only IV TOXICITY cautions Nephro oto Bactericidal action

Aminoglycosides Pseudomonas E.coli Klebsiella Often used along with other antibiotics

Quinolones Cipro Floxin Levaquin Tequin

Quinolones Excellent oral absorption Antacids interfere with absorption bactericidal

Quinolones Lower respiratory tract infections Bone & joint infections Infectious diarrhea UTIs Skin infections STDs Anthrax

Quinolone Side Effects HA N-V-D Allergic reaction

Others Vancomycin Tx of MRSA Must monitor blood levels Caution: oto & nephro-toxic

Nursing Instruct pt to take meds for full length of time – do not stop when feeling better Assess for s/s of superinfection All oral antibiotics are better absorbed if taken with a minimum of 6 – 8 ounces of water