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 ```