antimicrobials Flashcards
Ampicillin
Class; Antimicrobial
- 2nd generation PCN
- Broad spectrum
- Bactericidal
- Beta Lactam
Used; SSI prophylaxis and endocarditis prophylaxis
MOA; weakens bacterial cell wall and bind to penicillin binding protein and destroy bacteria
Dose; 2g IV 30 min before incision
Pharmacokinetics;
- E1/2 time; 1 - 2 hours
- Pb; 20%
- 50-90% excreted unchanged by Kidneys
Side effects;
- allergy/ anaphylaxis
- GI upset/ diarrhea
- skin rash
Contraindication; -hypersensitivity caution; -probenecid increases DOA -decaerse dose in renal dysfunction
Cefazolin (Ancef)
Class; Antimicrobial
- 1st generation cephalosporin
- Broad spectrum
- Bactericidal
- Beta Lactam
Uses; SSI prophylaxis, endocarditis prophylaxis
MOA; weakens bacterial cell wall and binds to penicillin binding protein and destroys bacteria
Dose; 1 - 2g IV 30 min before incision
Pharmacokinetics;
- E1/2 time; 2 hours
- Pb; 80%
- 80- 100% excreted unchanged by the kidneys
Side effects;
- anaphylaxis (1% cross reaction with PCN allergy)
- GI upset/ diarrhea
- skin rash
- thrombophlebitis
Contraindicated; -alcohol -PCN allergy caution; -decrease dose in renal dysfunction -probenecid increases DOA -crosses placenta
Gentamyocin
Class; Antimicrobial
- Aminoglycoside
- Broad spectrum
- Bactericidal
Use; TB, MRSA, sepsis, respiratory infections, endocarditis tx, GI/ GU surgery prophylaxis
MOA; Inhibits protein synthesis by binding to the 30S ribosomal subunit
Dose; 60 - 120 mg IV
toxic plasma level >9 mcg/mL
Pharmacokinetics;
-E1/2 time; 2 hrs
Pb; <30%
-extensively excreted unchanged by the kidneys
Side Effects;
- ototoxic
- nephrotoxic
- neurotoxic
- skeletal muscle weakness
Contraindications; -hypersensitivity caution; -myasthenia gravis enhances muscle weakness -NMBD prolongs muscle weakness (can be reversed with neostigmine and calcium gluconate) -other renal and ototoxic drugs -decrease dose in renal dysfunction -crosses placenta
Clindamyocin
Class; Antimicrobial
- Linomycin
- semi- synthetic narrow spectrum
- Bacteriostatic
Use; SSI prophylaxis with PCN allergy, Female GU surgeries
MOA; inhibits protein synthesis by binding to the 50S ribosomal subunit
Dose; 600 mg IV
Pharmacokinetics;
E1/2time; 2 - 3 hr
metabolized b the liver and 10% excreted unchanged by the kidneys
Side Effects;
- skeletal muscle weakness
- anaphylaxis
- GI upset/ diarrhea
- pseudomembraneous colitis
- blood dyscrasias
Contraindications; -hypersensitivity -hx of PseudoMembranous colitis caution; -prolongs NMBD (no reversal works) -myasthenia gravis; enhances muscle weakness -liver failure decrease the dose -crosses placenta
Vancomyocin
Class; Antimicrobial
- Glycopeptide
- Broad spectrum
- Bactericidal
Use;
- SSI prophylaxis with PCN allergy
- C. diff
- MRSA
- CSF and Shunt infection
- Cardia and ortho procedures with prosthetics
MOA; Inhibits bacterial cell wall synthesis by inactivating cell wall precursors; causing cell lysis and death
Dose; 1g or 10 - 15 mg/kg over 1 hr q 12hrs
Pharmacokinetics;
- E1/2 time; 6 hours (up to 9 days in renal failure)
- Pb; 10 - 50%
- 80 -90 % excreted unchanged by the kidneys
- narrow therapeutic range
Side Effects;
- Red mans syndrome, histamine release
- hypotension and cardiovascular arrest with rapid infusion
- GI upset/ diarrhea
- nephrotoxic
- ototoxic
- thrombophlebitis
Contraindications; -rapid infusion; Give over an hour -other nephro and ototoxic drugs -hearing loss -renal failure caution; -decrease dose in renal dysfunction -narrow therapeutic index check serum levels)
Metrondiazole (Flagyl)
Class; Antimicrobial
- Synthetic anti bacterial agent
- Broad spectrum
- Bactericidal
Use; C. diff, CNS infection, Abdominal sepsis, Colorectal surgery prophylaxis
MOA; activated Flagyl form cytotoxic compounds that bind to proteins and membranes and destroy bacteria
Dose; 500 mg IV
Pharmacokinetics;
- E1/2 time; 8 hours
- Pb; < 20%
- metabolized by the liver to 2-hydroxymethy metabolite
- 70% excreted unchanged b y the kidney
Side Effects;
- metallic taste
- dry mouth
- nauseas
- Neuropathy and pancreatitis (rare)
Contraindications; -Alcohol -Pregnant women caution; -seizure hx -CHF
Ciprofloxacin
Class; Antimicrobial
- Fluoroquinolone
- Broad spectrum
- Bactericidal
Use; TB, Anthrax, GI/GU infections, Gonorrhea
MOA; Inhibits bacterial enzyme used in DNA replication and cell division
Dose; 200 - 400 mg IV over 1 hr
Pharmacokinetics;
- E1/2time; 3 hours
- Pb; 20 - 40%
- metabolized in liver by CYP450
- 50% excreted unchanged b the kidneys
Side Effects;
- QT prolongation
- tendinitis
- Achilles tendon rupture (increased risk >65 and corticosteroid use)
- anaphylaxis
- nausea
- CNS disturbance
- photosensitivity (sunburn)
- rash
- mild GI irritation
Contraindications;
-Pregnant women
-<18 IV from (Achilles tendon rupture)
caution;
-myasthenia gravis; enhances muscle weakness
-decrease dose in renal dysfunction
-CYP450 interactions (increases levels of theophylline, warfarin, and tinidazole)
