Antimicrobials. Flashcards
Gram + bacteria
Thin cell wall (2 layer)
Staphylococcus, streptococcus, Diptheria, listeria
Gram - bacteria
Thick cell wall (3 layer) Beta lactam chains
Neisseria meningitidis, Neisseria gonorrhea, E. coli, salmonella
Mycobacterium
Waxy cell wall that makes it hard to kill.
Tuberculosis, Leprosy
Aerobic Bacteria
require 02
found in Mouth, GI, Lungs, Skin
S. aureus–skin infection
Pseudomonas aeruginosa–Lung infection
Anaerobic bacteria
Don’t require 02
Produce abscesses and tissue necrosis
Clostridium perfringens–gangrene
Actinomyces–abdominal/pelvic infections
Bactericidal Antibiotics
• Kills bacteria directly
• Can weaken cell wall
• Binds to ribosomes to decrease protein synthesis
▫ Cannot replicate
• Interfere with enzymes
▫ Prevent replication and promote cell death
• Eventually destroys all the bacteria
▫ Need to complete full course of treatment
Bacteriostatic Antibiotic
• Do not kill bacteria directly
• Bind to ribosomes to decrease protein synthesis
▫ Decreases the number of bacteria
▫ Allows the body’s natural immune system to kill the remaining bacteria
Broad Spectrum (class)
• Effective on a broad range of bacteria
• Action is directed toward the similar characteristics of different types of bacteria
▫ Cell wall
Narrow Spectrum (class)
- Effective on a narrow range of bacteria
* Action is directed towards a few types of bacteria
Culture and Sensitivity
• Determine the types of antibiotics a particular bacteria is sensitive to
▫ Expose the bacteria to various antibiotics
▫ 24-28 hours to complete
Goal of Drug Therapy for Infections
Kill bacteria
- Interrupt cell-wall synthesis
- Inhibit protein synthesis
- Inhibit DNA replication or cell division
- Inhibit folic-acid synthesis
Penicillins- Amoxicillin
-cillin Broad Spectrum Interrupts cell was synthesis ▫ Weakens and destroys cell wall Inhibits cell wall enzyme **Human cells don’t have a cell wall so they remain untouched** ▫ Bactericidal – kills bacteria directly
Nursing Considerations
• GI symptoms
▫ Diarrhea, N/V
▫ Pseudomembranous colitis or Clostridium Difficile (rare – due to suprainfection because of over growth of opportunistic infections)
• Candida albicans
• Allergy
▫ Rash, hives during first days of therapy
• Anaphylactic reaction
• Cephalosporin usually prescribed in its place, but can have a “cross-reaction” with this drug as well.
• Penicillin G formulation has high concentrations of sodium and potassium ▫ Why is this a potential problem? • Report bloody stools/watery diarrhea • Report s/s of candida infections ▫ Report mouth pain ▫ Report vaginal burning, itching or discharge • Report s/s of allergy ▫ Report difficulty breathing
What should you take penicillins with?
Water. Not juice, acid can nullify drugs action.
How long to monitor patient after PCN
30 mins
Cephalosporins- Cephalexin (Keflex)
Ceph-
Broad Spectrum
Interrupts cell wall synthesis.
• First-generation cephalosporin
▫ Similar to PCN (can cause an allergic reaction if pt is allergic to PCN.)
• Treats infections of gram-positive cocci
• Weaken/destroy cell wall
• Bactericidal
PCN contraindications/precautions
- Allergy to PCN
- Infectious mononucleosis
- Severe liver disease
- Allergy to PCN
- Infectious mononucleosis
- Severe liver disease
Cephalosporin
Contraindications/precautions
• Allergy to cephalosporins • Viral infections • Allergy to PCN • Renal failure Liver/GI disease
Cephalosporin, Nursing considerations
• GI ▫ Diarrhea, nausea, vomiting ▫ Pseudomembranous colitis • Cross allergy to PCN • Renal function – like what
- Assess for penicillin allergy; may have cross-allergy.
- Give orally administered forms with food to decrease GI upset even though this will delay absorption.
- Some of these drugs may cause a disulfiram (Antabuse)-like reaction when taken with alcohol.
monobactams- aztreonam (Azactam)
-nam, -tam
Narrow spectrum
▫ Gram negative aerobic bacteria
Moderately severe systemic infections
UTI’s
Abdominal/Gynecological infections in combo with other drugs
• Weaken and destroy cell wall
• Bactericidal
▫ NOT effective against anaearobic/gram positive
▫ Can be given to patients who have PCN allergies
Monobactams
Nursing considerations
- Thrombophlebitis/inflammation at IV site
- Rash, nausea, vomiting, diarrhea
- Suprainfection with Candida Albicans
Monobactams
Contraindications/precautions
- Viral infection
- Lactation
- History of allergies to PCN, cephalosporins
- Liver disease
- Renal failure/dialysis
Carbapenem- imipenem and cilastatin (primaxin)
-enem
Cell-wall synthesis
Broad Spectrum
▫ Bone, joint, skin, soft tissue infections
▫ Bacterial endocarditis with S. aureus
▫ Intraabominal infections
▫ Others
• Inhibits cell wall synthesis
▫ Cilastin inhibits enzyme that breaks down imipenem
• Bactericidal
• Resist beta-lactamase so bacteria can NOT develop resistance
Carbapenem
Nursing Considerations
• GI symptoms ▫ Usually occur when IV infusion is administered too rapidly • Thrombophlebitis • Cross-sensitivity with PCN/cephalosporins • Suprainfection ▫ Kills good and bad bacteria • Seizures ▫ Older adults ▫ Renally impaired patients
Carbapenem
Contraindications
• Allergy to cabapenems • Allergy to PCN • Allergy to cephalosporins • Seizures and other CNS disorders • Renal impairment ***Monobactam, penicillin and cephalosporins may decrease the effects***
Vancomycin (Vancocin)
Does not have a beta lactam ring
-mycin Cell wall synthesis • Reserved for Severe infections ▫ MRSA ▫ Pseudomembranous colitis that has caused C. diff ▫ Infections in patients with PCN allergy • Weakens and destroys cell wall • Bactericidal • PO form for C. Diff • IV forms for other infections
Vancomycin
Nursing Considerations
• Hypotension/Red person syndrome with rapid IV infusion
▫ Rapid release of histamine when infused too quickly.
▫ Infuse over at least an hour.
▫ Not an allergy
• Ototoxicity
▫ Hearing loss
▫ Baseline—do they have hearing loss already
• Nephrotoxicity
▫ Monitor BUN, creatinine (memorize these)
▫ Watch for other meds that are hard on kidneys
• Thrombophlebitis
▫ Redness, tenderness to IV site
• Draw a trough immediately before next dose!
▫ Fairly narrow therapeutic range
▫ Too high, damage to kidneys and ears
▫ Trough—10-20 mcg/L
• PO form does not absorb in GI but lines the walls.
Vanco
Contraindications
• Allergy to vancomycin • Allergy to corn products ▫ Contain dextrose • Renal insufficiency • Hearing impairment • Colitis/inflammatory disorders of the colon
Vanco Interactions
• Metformin may increase risk lactic acidosis
• Other drugs that are also nephrotoxic or ototoxic
• Incompatible with multiple IV medications
▫ Must look up to make sure before administering with other meds.
Tetracyclines
-cyclines Protein synthesis • First choice for ▫ Chlamydia ▫ Mycoplasma ▫ Rickettsia infections (Rocky Mountain Fever) ▫ Syphilis ▫ Gram positive infections Cholera Anthrax ▫ Acne vulgaris • Broad spectrum • Inhibit protein synthesis • Bacteriostatic – blocks bacterial reproduction ▫ Can give large doses ▫ Can give to resistant bacteria
