Antimicrobials

Question 1

Penicillin

Answer 1

-cillin
Bactericidal
β-lactam ring
Interferes w/ peptidoglycan synthesis
Renal excretion
*Hypersensitivity
Cross-reactivity w/ Cephalosporins

Question 2

Penicillin Dose

Answer 2

100mg/kg PO or IV

Question 3

Cephalosporin

Answer 3

Bactericidal
Inhibits bacterial cell wall synthesis
Low toxicity
Renal excretion
Broad spectrum
*Cross-reactivity w/ Penicillins

Question 4

Cephalosporin 1st Generation

Answer 4

Cefazolin (Ancef)

Question 5

Cephalosporin 2nd Generation

Answer 5

Cefuroxime

Question 6

Cephalosporin 3rd Generation

Answer 6

Cefotaxime

Question 7

Cephalosporin 4th Generation

Answer 7

Cefepime

Most effective

Question 8

Ancef Dose

Answer 8

<50kg weight-based
50-70kg 1g
70-120kg 2g
>120kg 3g

Question 9

Macrolides

Answer 9

-thromycin
BacterioSTATIC
Binds to 50S & blocks translocation step in protein synthesis
Used to treat gram+ bacilli, mycoplasma, upper/lower respiratory infections, ulcers, STDs
N/V when taken on empty stomach
Potential liver toxicity

Question 10

Erythromycin

Answer 10

Macrolide
Bacteriostatic OR bactericidal depending on the organism & dose
Inhibits bacterial protein synthesis
CYP450 metabolism
Excretion 1° via bile

Question 11

Erythromycin SE

Answer 11

GI intolerance most common
IV infusion → severe N/V
↑gastric emptying time
QT effects (prolongs cardiac repolarization)
Thrombophlebitis w/ prolonged IV use
Inhibits P-450 (drug interactions) & ↑QTc

Question 12

Clindamycin

Answer 12

Linomycin antibiotic
BacterioSTATIC
Binds to 50S & inhibits peptidyl transferase & translocation
Hepatic metabolism
10% excreted unchanged via urine 90% inactive
Half-life 2.5hr
DOSE 900mg

Question 13

Clindamycin Clinical Uses

Answer 13

Female GU surgery most common
Oral infections
Lung abscess
Aspiration pneumonia
Necrotizing fasciitis
GYN or pelvic infections
MRSA

Question 14

Clindamycin SE

Answer 14

Skin rash
Prolonged pre & post junction effects at NMJ w/o NDMR (prolongs NMBD & muscle weakness)
N/V or diarrhea
Fever or rash
C Diff enterocolitis
Pseudomembranous colitis → severe diarrhea (discontinue therapy)

Question 15

Vancomycin

Answer 15

Glycopeptide derivative 
Bactericidal
Impairs cell wall synthesis
90% excreted unchanged via urine 
Elimination 1/2 time 6hr (prolonged in renal failure)

Question 16

Vancomycin Dose

Answer 16

10-15mg/kg IV over 60min
1g mixed in 250mL
Infuse over pump

Question 17

Vancomycin Clinical Uses

Answer 17

Gram+ bacteria
Drug of choice to treat MRSA
Severe staph infections
Cardiac/ortho procedures using prosthetic devices
CSF & shunt related infections
Synergistic action w/ Aminoglycosides
Penicillin/Cephalosporin β-lactam allergy
Reserved for bacterial infections resistance to other antibiotics or patients w/ severe hypersensitivity

Question 18

Red Man Syndrome

Answer 18

Occurs after rapid (<30min) Vancomycin infusion → profound hypotension d/t histamine release
Intense facial & truncal erythema (flushing)
Treatment 1mg/kg Diphenhydramine + 4mg/kg Cimetidine 1hr prior to admin to limit histamine release

Question 19

Aminoglycosides

Answer 19

-mysin
Bactericidal
Irreversible protein synthesis 30S inhibition
Effective against aerobic gram+/- bacteria
Mycobacterium tuberculosis
*Administer w/ cell wall synthesis inhibitor

Extensive renal excretion
Elimination 1/2 time 2-3hr (↑20-40x w/ renal failure)

Question 20

Aminoglycosides SE

Answer 20

Ototoxicity
Nephrotoxicity
Skeletal muscle weakness
NDMR blockade potentiation (relaxation)
Paralysis usually reversible w/ calcium gluconate or Neostigmine
Pregnancy category C

Question 21

Fluroquinolones

Answer 21

-floxacin
Bactericidal
Inhibits DNA gyrase & topoisomerase IV
GI absorption rapid & excellent tissue penetration
Renal excretion (↓dose in renal dysfunction)
Elimination 1/2 time 3-8hr
Broad spectrum used to treat enteric gram negative, mycobacterium, & complicated GI/GU infections

Question 22

Ciprofloxacin Clinical Uses

Answer 22

Fluroquinolone
Systemic infection including bones, soft tissue, & respiratory tract
Tuberculosis
Anthrax

Question 23

Moxifloxacin

Answer 23

Fluroquinolone
Long-acting treatment
Acute sinusitis, bronchitis, & complicated abdominal infections

Complications include QT prolongation, peripheral neuropathy, psychosis, Stevens-Johnson syndrome, & Achilles tendon rupture

Question 24

Fluroquinolones SE

Answer 24

Mild GI disturbances
N/V
CNS dizziness or insomnia
Achilles or tendon rupture
Muscle weakness in patients w/ myasthenia gravis
Pregnancy category C

Question 25

Sulfonamides

Answer 25

BacterioSTATIC
Sulfamethoxazole-trimethoprim (Bactrim)
Inhibit folate production microbial synthesis
Partial acetylated in liver & other renal excretion
↓dose w/ renal disease
Used to treat UTIs, inflammatory bowel disease, & burns

Question 26

Sulfonamides SE

Answer 26

Skin rash (anaphylaxis)
Photosensitivity
Allergic nephritis
Drug fever
Hepatotoxicity
Acute hemolytic anemia
Thrombocytopenia
↑PO anticoagulant effect

Question 27

Nitroimidazole

Answer 27

Bactericidal
Metronidazole (Flagyl)
Anaerobic gram- bacilli clostridium
Good PO absorption
Widely distributed in tissues (including CNS)

Question 28

Flagyl Clinical Uses

Answer 28

Nitroimidazole
CNS infections
Abdominal/pelvis sepsis
Pseudomembranous colitis (C Diff) → combination therapy w/ Vancomycin
Endocarditis
Recommended preop colorectal surgery prophylaxis

Question 29

Flagyl SE

Answer 29

Dry mouth
Metallic taste
Nausea
Avoid alcohol

Question 30

Antimycobacterial Agents

Answer 30

Rifampin
Ethambutol
Pyrazinamide
Isoniazid (INH)

Distributed through tissues & CSF
1st line agents
*Combination therapy to treat active or latent TB
Initial 3-4 agents x2 mos
Followed by 2 agents x4 mos minimum therapy
BacterioSTATIC antibiotics require longer treatment course

Question 31

Rifampin

Answer 31

Bactericidal
Hepatic enzyme induction
Hepato-renal toxicity
Enzyme inducer
Thrombocytopenia/anemia
Discoloration (teeth, saliva, sweat, sputum, urine, feces)

Question 32

Ethambutol

Answer 32

BacterioSTATIC

Optic neuritis

Question 33

Pyrazinamide

Answer 33

BacterioSTATIC

Liver toxicity

Question 34

Isoniazid

Answer 34

BacterioSTATIC
Bactericidal when bacteria are actively dividing
Hepato-renal toxicity

Question 35

Antifungal

Answer 35

Amphotericin B
Poor PO absorption
Slow renal excretion
Renal toxic → 80% patients renal function impaired
- Most recover after drug stopped
- Possible permanent damage ↓GFR
Monitor plasma creatinine levels
Used to treat yeast or fungal infection

Question 36

Acyclovir

Answer 36

Antiviral
Selectively inhibits HSV1/2 replication & varicella zoster virus
Difficult to kill virus & not host cell
Potential drug therapy at cell surface receptors unique to the virus
Used to treat herpes

Question 37

Interferons

Answer 37

Antiviral
Glycoproteins produced in response to viral infections
Bind to receptors on host cell membranes & induce enzyme production that inhibits viral replication → degrade viral mRNA
Used to treat chronic hepatitis B/C

Question 38

Interferons SE

Answer 38

Flu-like symptoms
Hematologic toxicity
Depression or irritability
Impaired mental concentration
Autoimmune conditions development
Rashes/alopecia
Changes to CV, thyroid, or hepatic function (similar to chemo)
VERY difficult treatment

Question 39

Antiretroviral

Answer 39

Nucleoside/non-nucleotide reverse transcriptase inhibitors (NRTIs/NNRTIs Delavirdine)
Protease inhibitors (Ritonavir)
Fusion inhibitors (Enfuvirtide)
CCR5 receptors antagonists 
Integrase inhibitors (Lamivudine)

HIV treatment regimen
Triple therapy approach

Question 40

Antiretroviral SE

Answer 40

Liver toxicity
Peripheral neuropathy
Nephrotoxicity
Neuromuscular weakness
Interactions w/ other medications