Antimicrobials Flashcards
Antibiotic
A chemical produced by a microorganism, has ability to harm others.
Antimicrobial
Any agent that kills or suppresses microorgamisms
Selective Toxicity
Ability of a drug to kill or suppress infecting microorganisms without causing injury to host.
Use of antimicrobials.
- Treat infection
- Prophylactic use:
a. Surgery
b. bacterial endocarditis
c. neutropenia
Misuses of antimicrobials.
- attempted treatment of untreatable infections
- treatment of fever of unknown origin
- improper dosage
- Improper drug for organism
- omission of surgical cleaning/drainage
Drug resistance
Microorganisms able to alter function or structure-changes in microbial DNA.
Mechanisms of Antimicrobial action
a. Inhibitors of Cell Wall synthesis.
b. Bacteriostatic inhibitors of protein synthesis
c. Bactericidal inhibitors of protein synthesis.
Inhibitors of cell wall synthesis.
- Penicillins
- Cephalosporins
- Carbapenems
- Vancomycin
Bacteriostatic inhibitors of protein synthesis.
Do not cause cell death, slows microbial growth.
- Tetracyclines
- Macrolides
Bactericidal inhibitors of protein synthesis
- Aminoglycosides; Gentamicin/ Garamycin
Narrow-spectrum, penicillinase sensitive
Penicillin G
Penicillin V
Narrow-spectrum, penicillinase resistant
Nafcillin/Nallpen
Dicloxacillin/Dynapen
Oxacillin/Bactocil
Methicillin (now obsolete)
Broad Spectrum Penicillin
ampicillin/pricipen
amoxicillin/Amoxil
Extended spectrum Penicillins
Piperacillin/Piparcil
ticarcillin/Ticar
Penicillin + Beta Lactamase inhibitors
Augmentin: amoxicillin + clavulanic acid
Unasyn: ampicillin + sulbactam
Penicillin G
MOA: Weakens bacterial cell wall by binding to penicillin-binding proteins –> allows water to enter cell, ruptures cell.
IND: Gram pos Bacteria, Gram neg cocci
AE: Pain at injection site, allergic reactions
DI: aminoglycosides
NURS: Medic alert bracelets, Dont mix with aminoglycosides
1st Gen. Cephalosporins
Cefazolin/ Ancef, Kefzol
Cephalexin/ Keflex
MOA: Bind to penicillin-binding proteins and inhibit bacterial cell wall synthesis –> weakens cell wall, causes lysis and death.
IND: Gram pos - Strept, staph infections, Pre-surgery prophylactic.
AE: Allergic reactions, Bleeding, Thrombophlebitis
DI: Alcohol, Drugs that promote bleeding
NURS: Use cautiously in patients with penicillin allergy, Monitor PTT
2nd Gen. Cephalosporins
Cefuroxime/ Ceftin
Cefoxitin/ Mefoxin
MOA: Bind to penicillin-binding proteins and inhibit bacterial cell wall synthesis –> weakens cell wall, causes lysis and death.
IND: Gram pos - Staph infections, Resp. infections, Sinus, Ear Infections
AE: Allergic reactions, Bleeding, Thrombophlebitis
DI: Alcohol, Drugs that promote bleeding
NURS: Use cautiously in patients with penicillin allergy, Monitor PTT
3rd Gen. Cephalosporins
Ceftriaxone/ Rocephin
Cefixime/ Suprax
MOA: Bind to penicillin-binding proteins and inhibit bacterial cell wall synthesis –> weakens cell wall, causes lysis and death.
IND: Broad spectrum, Gram Neg, Reaches CSF.
AE: Allergic reactions, Bleeding, Thrombophlebitis
DI: Alcohol, Drugs that promote bleeding
NURS: Use cautiously in patients with penicillin allergy, Monitor PTT
4th Gen Cephalosporins
Cefepime/ Maxipime
MOA: Bind to penicillin-binding proteins and inhibit bacterial cell wall synthesis –> weakens cell wall, causes lysis and death.
IND: Strongest, Reaches CSF easier.
AE: Allergic reactions, Bleeding, Thrombophlebitis
DI: Alcohol, Drugs that promote bleeding
NURS: Use cautiously in patients with penicillin allergy, Monitor PTT
Carbapenem: Imipenem/ Primaxin
MOA: Binds to penicillin binding proteins –> weakens bacterial cell wall causing lysis, cell death. Mixed i combo with cilastatin
IND: Gram Pos, Gram Neg Bacteria
Resistant organisms, mixed infections, can reach CSF
AE: GI Effects, Allergic Reactions, suprainfections
Vancomycin
MOA: Inhibits cell wall synthesis causing lysis and death. Binds to molecules that serve as precursors for cell wall synthesis.
IND: Serious Infections only- Gram Pos
Infection with MRSA
Antibiotic-associated pseudomembranous colitis: C. difficle
AE: Ototoxicity
Bacteriostatic Inhibitors of Protein Synthesis
Do not cause cell death, Slows microbial growth.
Tetracycline Types
tetracycline/ Sumycin
doxycycline/ Vibramycin
mincycline/ Minocin
Tetracycline
MOA: Suppress bacteria growth by inhibiting bacterial protein synthesis. Bind to ribosomal subunits, inhibits binding of ttransfer RNA to ribosome complex.
IND: Broad spectrum against Gram Pos and Gram Neg Tx of acne Tx of infectious disease Tx of PUD Tx of Periodontal disease
AE: GI irritation, discoloration of developing bones and teeth, suprainfection, hepatotoxicity, Renal toxicity, Photosensitivity
DI: Metal ions: calcium, irono, magnesium, aluminum, and zinc.
CI: Not used for children <8 yrs
Not for use during pregnancy
Not for pts with renal disease
NURS: Instruct Pts to avoid sun and wear sunscreen,
Dietary restrictions
Types of Macrolides
erythromycin/ E-mycin
azithromycin/ Zithromax
clarithromycin/ Biaxin
dirithromicin/ Dynabac
Erythromycin/ E-mycin
MOA: suppress bacterial growth by inhibiting bacterial protein synthesis. Binds to ribosomal subunit, blocks addition of new amino acids to peptide chain.
IND: Alternative for pts with penicillin allergy: Gram Pos, Gram Neg, Strept infections, resp tract infections, endocarditis, legionnaires, pertussis, and diptheria.
AE: GI effects
Hepatotoxicity
Cardiotoxicity
DI: Theophylline, Tegretol, Warfarin, Verapamil, Diltiazem, -azoles, HIV protease inhibitors
Gentamicin/ Garamycin
MOA: Binds to ribosomal unit and interferes with protein synthesis, causes production of abnormal proteins –> Gets inserted –>Weak points lead to cell death.
IND: aerobic gram neg bacilli - pseudomonas, E. coli. Klebsiella
Used in combo w/ Vanco to treat serious infections with gram pos
AE: Ototoxicity, Nephrotoxicity
CI: Pts with renal disease, Elderly
DI: Cephalosporins, Vancomycin, Penicillins, Ototoxic drugs, Nephrotoxic drugs.
NURS: Monitor drug levels
Monitor kidney function; BUN & Cr
Monitor for signs of Ototoxicity
Do not take for more than 10 days
Sulfonamides
Trimethoprim + Sulfamethoxazole (TMP/SMZ)/ Bactrim, Septra
MOA: Both Meds disrupt synthesis of folic acid, needed for bacterial biosynthesis of RNA and DNA.
IND: Gram Pos, Gram Neg
Bacterial infections: UTIs, ear infections, bronchitis
Protozoal infections: pneumocyxtic carinii pneumonia
AE: Hypersensitivity reactions
Hematological effects
Kernicterus
Renal damage from crystalluria
DI: Warfarin, Dilantin, Oral hypoglycemics
CI: Pregnant women near term, breastfeeding, Children < 2 months
NURS: Observe for hypersensitivity reactions
Avoid sun, wear sunscreen
Periodic blood work
Increase fluids
Fluoroquinlones:
Ciprofloxacin/ Cipro
MOA: Inhibits bacterial DNA enzyme –> prevents DNA replication
IND: Broad spectrum, aerobic Gram Neg & Gram Pos bacteria.
Infections: Resp tract, GI, UTI, bones, Skin, Joint Infections
Prevention of Anthrax
AE: GI effects, CNS effects, Candida infections, tendon rupture
DI: Theophylline, Warfarin, Antacids, Milk products, iron, Zinc
Metronidazole/ Flagyl
MOA: Taken up by cell , causes DNA strand breakage
IND: Anaerobic organisms, Protozoal infections, GI Infections, GU infections
AE: CNS effects, GI effects
DI: Alcohol, Warfarin
