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
