Antibiotics Flashcards
Anti-infective
Target foreign organisms that cause infection; goal is reduce organisms to allow immune response to eliminate
Narrow spectrum of activity
Effective against only a few microorganisms
Broad spectrum of activity
Effective against a wide variety of microorganisms
Antibiotics
Meds used to target invading bacteria
First identify the causative organisms through a culture and then potential antibiotic susceptibilities through a sensitivity test
Empiric therapy
Treatment of an infection before specific culture information has been reported or obtains
Definitive therapy
Antibiotic therapy tailored to treat organisms identified with culture
Prophylactic therapy
Treatment with antibiotics before exposure to prevent an infection
Superinfection
Occur due to destruction of normal flora during antibiotic therapy
Commonly c.diff and yeast infections
Most common hypersensitivity reactions
Difficulty breathing, significant rash, gives, or other skin reactions, and severe GI intolerance.
Bactericidal vs bacteriostatic
Bactericidal kills bacteria
Bacteriostatic inhibits growth of susceptible bacteria rather than killing them immediately
Antibiotics MOAs
Interference with cell wall synthesis, protein synthesis, or DNA replication
Alters permeability of cell membrane
Acting as metabolite to disrupt critical metabolic reactions inside the bacterial cell
Basic sites of antibiotic activity
Cell wall synthesis, DNA replication, RNA replication, Antimetabolites, protein synthesis (30 S ribosomes or 50S ribosomes)
Class of antibiotics
Sulfonamides, penicillines, cephalosporins, macrolides, quinolones, aminoglycosides, tetracyclines
Sulfonamides
Bacteriostatic, inhibit growth of susceptible bacteria by preventing bacterial synthesis of folic acid, do not effect human cells or certain bacteria; they can use preformed folic acid
Sulfonamides indications
Effective against both gram positive and gram negative bacteria
- treatment of UTIs before sensitivity is established
- Upper respiratory tract infections
- pneumocystis jiroveci pneumonia
- outpatient staph infections
Sulfonamide contraindications
Sulfa allergy, Celebrex, pregnancy, infants less than 2 months old
Sulfonamide interactions
Sulfonylureas, warfarin, phenytoin
Sulfonamide adverse effects
Blood- hemolytic and aplastic anemia, agranulocytosis, thrombocytopenia
integumentary- photosensitivity, exfoliative dermatitis, Stevens-Johnson syndrome, epidermal necrolysis
GI- nausea, vomiting, diarrhea, pancreatitis
Other- Hepatotoxicity, convulsions, crystalluria, toxic nephrosis, headache, peripheral neuritis, urticaria, cough
Natural penicillines
Penicillin G, penicillin V
Penicillinase-resistant drugs
Nafcillin
Aminopenicillins
Amoxicillin, ampicillin
Which acid is penicillins commonly combined with
Clavulanic acid
Examples of combination agents
Amoxicillin/clavulanic acid (augmenting)
Piperacillin/ tazobactam (zosyn)
Pencillins MOA
Disrupt cell wall synthesis, bacteria cells die from cell lysis,
Prevention and treatment of infections caused by susceptible bacteria
Penicillins contraindications
Usually safe and well-tolerated meds,
KDA, assess type of reaction that occurs in patients who state they are allergic to penicillins
Penicillins adverse effects
Allergic reactions, nausea, vomiting, diarrhea, abdominal pain
Penicillins interactions
Many interactions:
Nonsteroidal anti-inflammatory drugs (reduces efficiency on antibiotics)
Oral contraceptives (lowers effectiveness)
Warfarin
Others
Cephalosporins first generation
Good gram positive coverage, poor gram negative coverage
Parental and oral forms , Used for surgical prophylaxis and for susceptible staphylococcal infections