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