Antibiotics Flashcards
Four common mechanisms of action
Interfere with bacterial cell wall synthesis
Interfere with protein synthesis
Interfere with replication of DNA and RNA
Disruption of metabolite actions
Types of infections (for all antiinfectives)
Community-associated
Health care- associated
Superinfections
Occur when antibiotics reduce or eliminate normal bacterial flora
Antibiotic resistance
Bacterial infections become resistant to antibiotics d/t a variety of factors
Broad categories of antibiotics
Penicillins Cephalosporins Macrolides Quinolones Aminoglycosides Tetracyclines
Penicillins
MOA: inhibits bacterial cell wall synthesis
Indications: streptococcus, and staphylococcus
Contraindications: drug allergy
Adverse Effects: allergic reaction in 0.7% - 4%, nausea, vomiting, diarrhea
Interactions: aminoglycosides, NSAID’s, oral contraceptives, warfarin
Nursing Considerations:
- use 2nd form of BC if on this
- watch for allergic reaction
Key Drugs: Penicillins
penicillin G-
Given IV or IM
Treats STD syphilis
amoxicillin-
Commonly prescribed
Treats infections in ears, nose, throat, GU tract, skin, and skin structures
Cephalosporins
MOA: interfere with bacterial cell wall synthesis
Indications: effective broad spectrum antibiotics
Contraindications: allergy to Penicillins
Adverse Effects: diarrhea, abdominal cramps, rash, edema
Interactions: ETOH, antacids, oral contraceptives
Nursing Considerations:
- use 2nd form of BC if on this - these decrease antacid oral adsorption - take 2 hours after or before drug
Key Drugs: Cephalosporins
cefazolin- prophylaxis in surgery
cephalexin- streptococcus and staphylococcus infections
cefoxitin- abdominal surgeries d/t effectiveness against abdominal organisms;
ceftriaxone- long acting; treats meningitis d/t ability to cross BBB, also be given IM (this is a PAINFUL injection but may need only ONE dose)
Macrolides
MOA: bacteriostatic drugs which inhibit protein synthesis
Indications: wide variety of infections
Contraindications: known drug allergy
Adverse Effects: GI related: especially nausea and vomiting; VERY strong (aka “macro”) GI effects
Interactions: many drugs due to highly protein bound and metabolized in the liver
Nursing Considerations:
- stay hydrated
- no alcohol
- take with food and take 1st dose at home
- don’t take with juice
Key Drugs: Macrolides
erythromycin- respiratory and GI infections, topical for dermatological use; pts may NOT be able to tolerate GI effects
azithromycin- upper and lower respiratory infections; this is the Z-pack
clarithromycin- GU and respiratory infections
Tetracyclines
MOA: inhibit protein synthesis in susceptible bacteria
Indications: treatment of acne in adolescents & adults, treatment of Chlamydia, Mycoplasma, & Rickettsia
Contraindications: avoid in pregnant and nursing women, & children younger than 8 years old
Adverse Effects: PHOTOSENSITIVITY, GI upset, hematologic abnormalities
Interactions: antacids, dairy products, calcium, enteral feedings, & iron preparations reduce oral absorption
Nursing Considerations:
- wear sunscreen or stay out of sun - monthly blood work - take antacids and dairy 2 hrs after or before meds
Key Drugs: Tetracyclines
doxycycline- Very commonly used tetracycline Treats Rickettsial infections, chlamydial infections, & mycoplasmal infections Also used in treatment of acne Educate patients on adverse effects
Aminoglycosides
MOA: prevent protein synthesis in bacteria
Indications: used ONLY serious infections due to toxicity
Contraindications: not for use in pregnant women d/t crossing placenta - can cause congenital deafness
Adverse Effects: serious toxicities such as NEPHROTOXICITY, OTOTOXICITY, & NEUROTOXICITY
Interactions: other nephrotoxic drugs like vancomycin, cyclosporine, & amphotericin B
Nursing Considerations:
- watch for tinnitus, or if pts say ears are full - take labs, monitor I&O, BUN, creatinine - balance issues and parathesia (tingling of arms and legs)
Think THREE AMINO MICE
Key Drugs: Aminoglycosides
amikacin-
Treats infections which are resistant to Gentamicin or Tobramycin (DON’T use often d/t toxicity)
gentamicin-
Most COMMONLY used aminoglycoside
Treatment of gram neg. and gram + infections
