Antimicrobials Flashcards
Which classes of antibiotics are time-dependent?
Penicillins
Cephalosporins
Which classes of antibiotics are concentration-dependent?
Quinolones
Macrolides
What is unique about atypical bacteria? Clinical significance?
Lack a cell wall
Beta lactams, which target the cell wall, are not effective
What stain color are gram positive bacteria? Why?
Purple
Outer peptidoglycan layer
What stain color are gram negative bacteria? Why?
Red/pink
Un-exposed peptidoglycan layer
What are the 3 main mechanisms of action for antibiotics?
(1) Interfere with cell wall maintenance or synthesis
(2) Interfere with nucleic acid synthesis/function
(3) Interfere with protein synthesis
What classes of antibiotic (7 examples) interfere with cell wall synthesis and maintenance?
BETA LACTAMS
(1) Penicillins
(2) Cephalosporins
(3) Carbapenems
(4) Monobactams
(5) Vancomycin
(6) Fosofomycin
(7) Daptomycin
What classes of antibiotics (4 examples) inhibit nucleic acid synthesis/function?
(1) QUINOLONES: Inhibit DNA Gyrase +/- Topoisomerase IV
(2) TRIMETHROPRIM / SULFAMETHOXAZOLE: Inhibits folate synthesis
(3/4): METRONIDAZOLE, NITROFURANTOIN: Create free radicals
What classes of antibiotics (6 examples) inhibit protein synthesis?
(1) Aminoglycosides
(2) Clindamycin
(3) Linezolid
(4) Macrolides
(5) Tetracyclines
(6) Tigecycline
What is the unique side effect of carbapenem?
Seizures
What are the 4 groups of Beta Lactam antibiotics?
(1) Penicillins
(2) Cephalosporins
(3) Carbapenems
(4) Monobactams
Name 2 kinds of Natural Penicillins.
Natural Penicillins:
Benzathien penicillin, penicillin G
What are the 2 1st Generation Cephalosporins?
1st Generation:
Cefazolin, cephalexin
Name 3 kinds of Carbapenems.
Meropenem
Ertapenem
Imipenem
Name 1 kind of Monobactam.
Aztreonam
What are 2 unique traits about aztreonam?
(1) Only works on Gram (-)
(2) No cross sensitivity with PCN
Augmentin is a (abx class) that contains (abx name) and (beta-lactamase inhibitor).
Class: Penicillin
Name: Amoxicillin
BLI: Clavulanic Acid
Unasyn is a (abx class) that contains (abx name) and (beta-lactamase inhibitor).
Class: Penicillin
Name: Ampicillin
BLI: Sulbactam
Zosyn is a (abx class) that contains (abx name) and (beta-lactamase inhibitor).
Class: Penicillin
Name: Piperacillin
BLI: Tazobactam
1st generation cephalosporins have Primary Coverage against ____ and Secondary Coverage against ____. Two examples are: ______.
Primary Coverage: Gram + (except MRSA)
Secondary Coverage: None
Names: Cefazolin IV, Cefalexin PO
2nd generation cephalosporins have Primary Coverage against ____ and Secondary Coverage against ____. Two examples are: ______.
Primary Coverage: Anaerobes
Secondary Coverage: Gram + (except MRSA), Gram - (except Pseudomonas)
Names: Cefotetan, Cefoxitin
3rd generation cephalosporins have Primary Coverage against ____ and Secondary Coverage against ____. Three examples are: ______.
Primary Coverage: Gram - (only ceftazidine treats Pseudomonas)
Secondary Coverage: Gram + (except MRSA)
Names: Ceftriaxone, cefpodoxime, ceftazidine
4th generation cephalosporins have Primary Coverage against ____ and Secondary Coverage against ____. One example is: ______.
Primary Coverage: Pseudomonas
Secondary Coverage: Gram + (except MRSA), Gram -
Name: Cefepime
5th generation cephalosporins have Primary Coverage against ____ and Secondary Coverage against ____. One example is: ______.
Primary Coverage: MRSA
Secondary Coverage: Other Gram +, Gram -
Name: Ceftaroline
Which antibiotic group is effective in treating meningitis?
Cephalosporins
They have good penetration of meninges and CNS
What are the 3 drug names and generations of Quinolones?
2nd: Ciprofloxacin
3rd: Levofloxacin
4th: Moxifloxacin
Which 2 Quinolones are effective against bacterial respiratory infections?
(1) Levofloxacin
(2) Moxifloxacin
(especially DRSP)
QUINOLONES
- Mechanism of Action
- Indications
- Unique traits
- Side effects
- MoA: Inhibit bacterial DNA gyrase enzyme
- Indications:
(1) Cipro: UTI, prostatitis, intraabdominal, GI bone, joint + Anthrax
(2) Levo & Moxi: Community acquired PNA (DRSP) - Traits: Avoid Ca++, iron, antacids; poor CNS penetration
- Side effects: Elevated LFTs, inhibit caffeine metabolism causing insomnia
- QT interval prolongation, increased risk of AA
- Risk of tendonitis and rupture (elderly + steroids)
- Interferes with bone growth (young)
MACROLIDES
- Mechanism of Action
- Indications
- Unique traits
- Side effects
- MoA: Inhibit protein synthesis
- Indications:
(1) Respiratory infections: PNA (atypical)
(2) Acne, prophylaxis in dental procedures
(3) Alternative for PCN allergies - Traits:
(1) Azithro: Least side effects & interactions
(2) Clarithro: H. pylori infection; CYP inhibitor, many drug interactions
(3) Erythro: Severe gastric irritation - Side effects:
- QT interval prolongation (predispose to Vtach)
- Hepatotoxicity
- Confusion
TETRACYCLINES
- Mechanism of Action
- Indications
- Unique traits
- Side effects
MoA:
- Indications: broad-sprectrum = lots of uses
(1) Chlamydia: Lymphogranuloma venereum, endocervicitis, urethritis
(2) Mycoplasma: PNA
(3) Rickettsia: Q-fever, Rocky Mountain spotted fever
(4) Other bacteria: Acne, Lyme disease, H. pylori, syphilis, chancroid, cholera
(5) Protozoa: Balantidiasis - Side effects:
(1) Permanent teeth staining (2nd trimester till 8 years)
(2) Photosensitivity (use sun block)
(3) Hemolytic anemia
(4) Exacerbation of SLE
(5) Thrombocytopenia, coag abn
What are the 5 major side effects of Tetracyclines?
(1) Permanent teeth staining (2nd trimester till 8 years)
(2) Photosensitivity (use sun block)
(3) Hemolytic anemia
(4) Exacerbation of SLE
(5) Thrombocytopenia, coag abn
SULFANAMIDES
- Mechanism of Action
- Indications
- Unique traits
- Adverse effects
BACTRIM & SEPTRA
- MoA: Inhibits folate synthesis
- Indications:
(1) UTI
(2) Prophylaxis/treatment of opportunistic infections in HIV patients, especially Pneumocystis jirovecii (HIV PCP)
(3) Previously Sulfasalazine used in IBD - Adverse effects:
(1) Sulfa allergy (delayed cutaneous rxn, fever + rash)
(2) Bone marrow suppression & neutropenia
(3) Renal insufficiency
What are 2 contraindications of Sulfanamides?
(1) Folate deficiency anemia
(2) Heart failure, as sulfa abxs decrease K+
DAPSONE: A SULFONAMIDE
- Mechanism of Action
- Indications
- Adverse effects
ACZONE
- MoA: Bacterial folic acid synthesis inhibition
- Indications:
(1) LEPROSY
(2) Alternative med for HIV PCP
(3) Bullous pemphigoid & dermatitis herpetiformis - Adverse effects:
(1) Rash
(2) Hemolysis with G6PD deficiency
(3) Metheglobinemia
AMINOGLYCOSIDES
- Mechanism of Action
- Indications
- Unique traits
- Adverse effects
GENTAMICIN, TOBRAMYCIN, AMIKACIN
- MoA:
- Indications: Serious Gram -, also with BL for serious Gram +
(1) Intraabdominal infections
(2) Bacterial endocarditis
(3) Skin + bone infections
- Traits: IV only; peak and trough to ensure efficacy and avoid side effects; bacteriocidal
- Side effects:
(1) Ototoxicity (irreversible)
(2) Nephrotoxicity in 7 days (nephrotoxicity)
MISC: CLINDAMYCIN
- Mechanism of Action
- Indications
- Unique traits
- Adverse effects
- MoA:
- Indications:
(1) Staph & Strep ANAEROBIC infections ABOVE the diaphragm (lung abscess, aspiration PNA, oral cavity infections)
(2) Cellulitis, erysipelas, impetigo
(3) Pelvic infections (& BV & toxoplasmosis) - Adverse effects:
(1) GI troubles
(2) Higher risk of pseudomembranous colitis (C. diff)
MISC: LINEZOLID (oxazolidinones)
- Mechanism of Action
- Indications
- Adverse effects
- Interactions
- MoA: Inhibits bacterial protein synthesis
- Indications:
(1) Hospital-acquired PNA
(2) MRSA - even with PO - Adverse effects: Headache, nausea, diarrhea, vomiting
- Decreased platelet count
- Interactions:
(1) Potentiate vasopressors
(2) Serotonin syndrome with SSRIs
(3) Raise BP with tyramine foods (aged cheese, wine, soy sauce, smoked meat, fish)
MISC: METRONIDAZOLE
- Mechanism of Action
- Indications
- Adverse effects
- Interactions
FLAGYL
- MoA: Inhibits microbial DNA synthesis
- Indications:
(1) Anaerobic (intraabominal & gynecologic)
(2) Protozoal (amebiasis, giardia, trichomoniasis)
(3) C. diff - PO - Adverse effects: Metallic taste, dizziness, nasal congestion, reversible neutropenia, thrombocytopenia.
- -> OD causes seizures
- Interactions: Safe in pregnancy. Severe NV with ETOH.
- Increases toxicity of lithium, benzodiazepines, cyclosporine, CCBs.
MISC: NITROFURANTOIN
- Mechanism of Action
- Indications
- Adverse effects
- Interactions
- Unique trait
MACROBID
- MoA: Creates free radicals & interferes with nucleic acid synthesis/function
- Indications: UTIs caused by E. coli, S. aureus, Klebsiella spp., Enterobacter spp.
- Adverse effects: GI discomfort, dizziness, irreversible peripheral neuropathy, rarely fatal hepatotoxicity
- Interactions: Antacids reduce absorption. Probenecid reduces its excretion.
- Take on full stomach to give crystals time to break down
MISC: VANCOMYCIN
- Mechanism of Action
- Indications
- Adverse effects
- Interactions
- MoA: Binds to bacterial cell wall and inhibits its synthesis (not like BL)
- Indications: Gram +
(1) First choice for MRSA
(2) Second choice for C. diff (PO)
(3) Bone & joint infections, Staph blood infections (IV)
- Adverse effects: Ototoxicity & nephrotoxicity
- Red man syndrome: Flushing, itching of the head, neck, face
Name 6 antibiotics (2 groups) that are effective on MSSA infections.
PENICILLINS
- PO: Cloxacillin, Dicloxacillin
- IV: Oxacillin, Nafcillin
1st GENERATION CEPHALOSPORINS
- PO: Cephalexin
- IV: Cefazolin
Name 5 antibiotics that are effective on MAJOR MRSA infections.
(1) Vancomycin (televancin & oritavancin)
(2) Linezolid
(3) Daptomycin
(4) Ceftaroline
(5) Tigecycline
Name 3 antibiotics effective against vancomycin-resistant enterococci (VRE).
(1) Linezolid
(2) Daptomycin
(3) Tigecycline
Name 3 antibiotics that are effective on MINOR MRSA SKIN infections.
(1) TMP/SMX
(2) Clindamycin
(3) Doxycycline
If a patient has a PCN allergy, can we safely give Cephalosporins?
- If the pt has a minor allergy (maculoapular skin rash; Type II hypersensitivity) –> Cephalosporins OK
- If the pt has a severe allergy (anaphylaxis, hives; Type ! hypersensitivity) –> Avoid Cephalosporins.
- – Minor infections: Use Macrolides or Clinda
- – Severe infections: Use Vanco or Linezolid
What are the first & second line antibiotics to use in Strep infections?
(1) Penicillin (ampicillin, amoxicillin)
2) Vancomycin (used empirically
Name 4 antibiotics that can treat GI anaerobic infections.
(1) Metronidazole
(2) Carbapenems
(3) Piperacillin / ticarcillin
(4) 2nd generation cephalosporin
Name 2 antibiotics that can treat respiratory anaerobic infections.
(1) Clindamycin (anaerobic Strep- lung & dental abscess)
(2) Piperacillin, ticarcillin
Name 4 antibiotic drug groups that have NO anaerobic coverage.
(1) Aminoglycosides
(2) Aztreonam
(3) Cephalosporins (except cefotetan & cefoxitin)
(4) Oxicillin, nafcillin, cloxacillin, dicloxacillin
Name 3 antibiotics that can treat Pseudomonas infection.
(1) Cefepime
(2) Piperacillin
(3) Ticarcillin
Which antibiotic drug classes are effective against Gram - infections?
All except amoxicillin (needs body guard)