Chapter 90: Bacteriostatic Inhibitors of Protein Synthesis Flashcards
What does it mean when tetracyclines are bacteriostatic?
suppress bacterial growth and replication but do not produce outright kill
Four members of the tetracycline family are available for systemic therapy:
Tetracycline
Demeclocycline
Doxycycline
Minocycline
What bacteria can tetracycline kill?
broad spectrum antibiotics )wide variety of gram positive, gram negative, protozoa, and chlamydia)
Tetracycline MOA
inhibits protein synthesis
Therapeutic Uses of Tetracycline
Infectious Disease
Chlamydia Trachomatis (doxycycline)
Acne (topical or oral)
Cholera
Mycoplasma pneumonia
Lyme Disease (doxycycline)
Peptic Ulcer disease (H. Pylori)
Periodontal disease
Drug and Food Interactions of Tetracycline
Absorption is decreased if drug is given with:
Calcium supplements
Milk products
Iron supplements
Magnesium-containing laxatives
Most antacids
When are tetracyclines administered?
2 hours before or 2 hours within ingestion
Taken at night
Major Precautions for Tetracycline
- effect on bone and teeth (not for use in children under 8 or in pregnancy) - can cause discoloration of teeth
- tetracycline and demeclocycline are eliminated primarily in urine
- photosensitivity can lead to significant sunburn
- diarrhea may indicate a potentially life-threatening superinfection of bowel
- high dose IV therapy has been associated with severe liver damage (monitor ALT/AST)
Macrolides (Erythromycin)
- broad spectrum antibiotic (gram + and gram - bacteria)
- inhibition of bacterial protein synthesis
- erythromycin is oldest; azithromycin and clarithomycin are derivatives
- usually bacteriostatic, but can be bacteriocidal
- use if allergic to penecillin
Therapeutic Uses of Macrolides (Erythromycin)
- legionella pneumonia
- pertussis
- diptheria
- chlamydia
Drug Interactions of Macrolides
inhibits metabolism of many drugs
can increase plasma levels and 1/2 life
Adverse Effects of Macrolides (erythromycin)
Gastrointestinal (epigastric pain, N/V, diarrhea)
QT prolongnation and sudden cardiac death (if given high dose)
Superinfection
Phlebitits (IV)
Azithromycin (other macrolides)
like e-mycin and for respiratory tract infections
Advantage: short course of treatment - better compliance
Drug of choice for chlamydia
Linezolid (Zyvox)
oxazolidinones
first member of a newer class of antibiotics
inhibits protein synthesis (bacteriostatic)
Linezolid (Zyvox) Use
reserved for VRE (vancomycin resistant enterococci) and MRSA
