Protein synthesis inhibitors Flashcards
What are the main categories of protein synthesis inhibitors
Aminoglycosides
lincosamides
oxazolidinone
Macrolides
Streptogramins
tetracyclines
What drugs are considered aminoglycosides
Gentamicin
Amikacin
Tobramycin
What type of drugs are considered lincosamides
Clindamycin
What type of drugs are considered oxazolidinones
Linezolid
What type of drugs are considered Macrolides
Azithromycin
Clarithromycin
Erythromycin
What type of drugs are considered tetracyclines
Doxycycline
Minocycline
Tetracycline
What are the ribosomal subunits of protein synthesis that antibiotics can effect
30S
50S
tRNA
Which antibiotics effect 50s protein synthesis
Erythromycin
Chloramphenicol
Clindamycin
Which antibiotics effect 30s protein synthesis
tetracycline
gentamycin
tobramycin
amikacin
60% of classes of antibiotics target which part of the cell
Ribosomes / ribosomal RNA
Where on the ribosome do antibiotics bind
at moving parts
Aminoglycosides target which ribosomal subunit and are considered bactericidal or static
30s
bactericidal
Tetracyclines target which ribosomal subunit and are considered cidal or static
30s
bacteriostatic
Which bacteriostatic antibiotics target the 50s ribosomal subunit
Chloramphenicol
Clindamycin
Macrolides
which antibiotics are both bactericidal AND bacteriostatic and target the 50s ribosomal subunit
Linezolid
Streptogramins
What is the main target for aminoglycosides
Pseudomonas
What kind of interaction do aminoglycosides have when paired with B-lactams and vancomycin
synergistic
Do aminoglycosides have CNS penetration or GI absorption
No
What are the major side effects of aminoglycosides
Ototoxicity (Permanent)
vestibular toxicity (permanent)
renal toxicity (Reversible)
What drugs do you not combine with aminoglycosides
Loop diuretics
What is a complete contraindication for using aminoglycosides
M. Gravis
What type of drug is gentamicin and how is it administered
Aminoglycosides
IM / IV
What is gentamicin used for
Serious gram neg infections
-pseudomonas
-Enterobacter
-proteus
If a patient who has CF contracts pseudomonas or enterobacter… what would be the first line of treatment
gentamicin
When is Amikacin used
For gentamicin resistant bacteria
Would you administer a patient neomycin via IV
No, oral only because of toxicity
What is neomycin generally given for
Bowel surgery prophylaxis
What is the most widely used tetracycline
Doxycycline
Which type of tetracycline is best for someone with a CNS infection and why
Minocycline because its more hydrophobic
If a patient has chlamydia, rickettsia, or mycoplasma, what is the drug of choice to treat
Tetracycline
What is the number 1 Lyme treatment in the country
Doxycycline
What do you recommend to your patient who you are prescribing tetracycline to avoid GI distress
Take with food
DO NOT take with dairy or antacids
Which form of tetracycline is safe for renal impaired patients
Doxycycline
What are the adverse effects of tetracycline
Photosensitivity
Superinfections
Calcified tissue growth inhibitor in kids
Causes yellowing of teeth in kids
What is a new class of antibiotics derived from minocycline
Glycylcycines
When are tigecyclines used (glycylcycines)
As a last resort for MRSA, VRE and enterobacteria
What is the mechanism of action for chloramphenicol
Binds 50s subunit which blocks aminoacyl binding to acceptor site which inhibits peptidyl transferase and thus translation
What is unique about chloramphenicol
crosses the blood brain barrier
Where is chloramphenicol generally used
Mostly outside the US for Rocky Mountain spotted fever
What is the major adverse effect of chloramphenicol
grey baby syndrome (incomplete hepatic development)
What is erythromycin useful for
an alternative to penicillin for gram positive infections
How do clarithromycin and erythromycin differ
Clarithromycin has better activity against H. influenza, chlamydia, legionella, moraxella and helicobacter pylori
What is a generic name for azithromycin
Z pack
What is azithromycin typically used for
respiratory tract infections
Strep pharyngitis in PCN allergic patients
What is the drug of choice for Chlamydial STI
Azithromycin
Why is Erythromycin not administered via IV
It is associated with high incidence of thrombophlebitis
Why is azithromycin not given with food
food inhibits absorption
What is unique of azithromycin as a macrolide
Has the longest half life (68 hours)
Which patients would you not prescribe a macrolide
patients with hepatic dysfunction
What drug to drug interaction do you have to be aware of with macrolides
They cause CYP inhibition, so drugs like Digoxin will not be metabolized by the liver correctly and increase the levels in the body
What is the mechanism of action for clindamycin
Inhibits peptidyl transferase by binding to the 50s ribosomal subunit
How can clindamycin be administered
IV or PO
Is clindamycin narrow or broad spectrum
Narrow spectrum for gram + cocci
What is the primary use of clindamycin
Anaerobic bacterial infections
MRSA
If someone comes in with an abscess, what would you treat them with and why
Clindamycin because it is able to penetrate an abscess
What are major causes of C.Diff or pseudomonas colitis
Doxycycline
Clindamycin
What is the MOA for Linezolid
Binds to the 50s ribosomal subunit to inhibit protein synthesis
Is Linezolid bactericidal or bacteriostatic
Mostly bacteriostatic
What is linezolid bactericidal against
Streptococci and C. perfringens
What is the most common use for Linezolid
MRSA and VRE but is NOT the first line agent
What are the adverse effects of Linezolid
Serotonin syndrome when used in combo with anti-depressants
Dose dependent Thrombocytopenia
What are the main categories of antimetabolites / DNA gyrase inhibitors
Fluoroquinolones
Nitroimidazole
Rifamycins
Nitrofurantoin
What are the drugs that are involved with folate synthesis inhibitors
TMP-SMX
Co-trimoxazole
Which antibiotics are dihydrofolate reductase inhibitors
Trimethoprim
What is the MOA for fluoroquinalones
They inhibit type 2 topoisomerase (inhibit DNA duplication)
What antibiotics make up fluoroquinalones
Ciprofloxacin
Levofloxacin
Ofloxacin
Moxifloxacin
What is Moxifloxacin
4th gen fluoroquinolone that is safe for those with renal disease
What is second generation fluoroquinolone and what is it useful against
Ciprofloxacin
Psuedamonas aeruginosa*
*Think staph coverage
What is third generation fluoroquinolone and what is it useful against
Levofloxacin
Strep pneumoniae
*Think for respiratory infections
What is 4th generation fluoroquinalones
Moxifloxacin -> not for pseudomonas aeruginosa
If a patient comes in after taking antibiotics with tendinopathy or an achilles tendon rupture, what antibiotic were they most likely on
Cipro or other fluoroquinalones
What other adverse effects happen with fluoroquinalones
QT prolongation
articular cartilage erosion during development (avoid in children and pregnancy)
Patient presents with bacterial sinusitis caused by S. pneumoniae, H.influenza, or M.catarrhalis, what is the first line agent for treatment
Amoxicillin or amoxicillin+calvulanate
Patient presents with bacterial sinusitis caused by S. pneumoniae, H.influenza, or M.catarrhalis, what is the first line agent for treatment if they are allergic to penicillin
Doxycycline
What is a last resort alternative for penicillin allergic patients with bacterial sinusitis
Respiratory fluoroquinolone (levo or moxifloxacin)
A patient with severe sinusitis presents with bacterial bronchitis (most likely cause by pseudomonas). What are you going to treat them with first
IV antipsuedamonal such as cefepime
What are the most common cause of a UTI
E.Coli
staph
K. pneumoniae
A patient presents with a UTI, what are you going to treat them with
Nitrofurantoin
Amoxicillin
Cephalosporin
Trimethoprim/sulfamethoxazole (if not pregnant)
What is the brand name of Nitrofurantoin
Macrobid
When is Nitrofurantoin used
UTIs
What is the most common species targeted by metronidazole
Bacteroides
A patient presents with Helicobacter Pylori infection, what might you give them as a treatment
Metronidazole
What is the most common side effect of metronidazole
GI upset
What are you going to advise your patient that is taking metronidazole
Avoid alcohol
What is the MOA for sulfonamides
They inhibit folate metabolism
What is the MOA for Trimethoprim
Inhibit dihydrofolate reductase
Which antibiotics make up Bactrim and why
Sulfamethoxazole and trimethoprim
They are bacteriostatic alone but when combined turn bactericidal
What is the dosing ratio of sulfamethoxazole trimethoprim
5:1
What are the common side effects of Bactrim
Rash (common)
SJS (rare)
Neonatal kernicterus
What is neonatal kernicterus
Bilirubin encephalopathy caused by sulfa
What is Bactrim most useful against
UTI
Biliary tree infections
PJP
Toxoplasmosis
Salmonella
What is the MOA of Rifampin
Inhibit RNA polymerase
Bactericidal
When is rifampin used
Mycobacterium tuberculosis (cannot use alone)
Why do you have to be careful when giving rifampin
There is a large capacity for drug-drug interactions
What is an adverse effect of rifampin
Orange-red tears, saliva, urine & sweat
What is the MOA of Isoniazid
Inhibits the synthesis of mycolic acids (Essential component of mycobacterial cell wall)
What combo of drugs treats most strains of TB
Isoniazid and Rifampin
What are the phases of treating TB
Intensive phase: 4 drug combo (2 months)
The last 7 months: Isoniazid and rifampin
What is ethambutol MOA
Inhibits mycobacterial arabinosyl transferase
How is ethambutol given and why
With other anti-TB drugs to prevent resistance