Inhibitors of Bacterial Protein Synthesis Flashcards

1
Q

Aminoglycosides

A
Amikacin
Gentamicin
Neomycin
Streptomycin
Tobramycin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Aminoglycosides - Adverse effects

A

Most serious: Nephrotoxicity and Ototoxicity (vestibular and cochlear)

Vestibular toxicity manifestations: Dizziness, impaired vision, nystagmus, vertigo, nausea, vomiting, and problems with postural balance and walking

Cochlear toxicity manifestations: Tinnitus and hearing impairment and can lead to irreversible deafness

Drug-induced renal failure (acute tubular necrosis, when they accumulate in proximal tubule cells)

Glomerular toxicity

High dose: respiratory paralysis (cuarare-like effect with neuromuscular blockade). Reversible by calcium gluconate or neostigmine.

Hypersensitivity (infrequently)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Aminoglycosides tendency to cause cochlear or vestibular toxicity

A

Amikacin produces more cochlear toxicity (deafness),

Gentamicin and streptomycin cause more vestibular toxicity.

Tobramycin appears to cause similar degrees of cochlear and vestibular toxicity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Most nephrotoxic aminoglycosides

A

Neomycin, Tobramycin and Gentamicin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Aminoglycosides - MoA

A

Bind 30S ribosomal subunit, interfering with initiation of protein synthesis and cause misreading of the genetic code

Breakup of polysomes into nonfunctional monosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Amikacin - Clinical use

A

Strains of Proteus, Pseudomonas, Enterobacter, and Serratia

Joint infections 
Intra-abdominal infections 
Meningitis
Pneumonia
Sepsis
Urinary tract infections

Strains of multidrug-resistant Mycobacterium tuberculosis, including streptomycin-resistant strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Gentamicin - Clinical use

A

Mainly in severe infections (eg, sepsis and pneumonia) caused by gram-negative bacteria that are likely to be resistant to other drugs

E. coli, Klebsiella, Enterobacteriae
P. aeruginosa
Serratia marcescens
Proteus
Acinetobacter 

In combination with a penicillin to treat serious enterococcal, staphylococcal, or viridans group streptococcal infections such as endocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Tobramycin - Clinical use

A

The most active aminoglycoside against many strains of Pseudomonas aeruginosa

Enterococcus faecalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Streptomycin - Clinical use

A

Tuberculosis and infections caused by Yersinia pestis (plague) and Francisella tularensis (tularemia)

Sometimes brucellosis

Penicillin plus streptomycin is effective for enterococcal endocarditis and 2-week therapy of viridans streptococcal endocarditis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Neomycin - Clinical use

A

Gram-positive and gram-negative and some mycobacteria

Superficial infections

Prevents Hepatic encephalopathy and Hypercholesterolemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Paromomycin - Clincal use

A

has recently been shown to be effective against visceral leishmaniasis when given parenterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Drugs that have similar properties as Neomycin

A

Kanamycin and Paromomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Tetracylines - MoA

A

Binds to 30 S ribosomal subunit, prevents addition of new amino acid to the nascent polypeptide chain. Bacteriostatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tetracyclines

A

Doxycycline
Minocycline
Tetracycline
Tigecycline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Tetracylines - Clinical use

A
Lyme disease
Rocky Mountain spotted fever
Relapsing fever
Ehrlichiosis
Granuloma inguinale
Brucellosis
Cholera
Peptic ulcer disease
Gonorrhea (doxycycline in combination with ceftriaxone)
Community acquired pneumonia
Leptospirosis (leptospira)
Nontuberculous mycobacterial infections (Mycobacterium marinum)

Prophylaxis of protozoal infections (plasmodium falciparum)

H. pylori
Chlamydia trachomatis
Rickettsiae
Acne vulgaris
MRSA
Spirochetes
Mycoplasmas
Protozoa
Borrelia burgdorferi
Borrelia recurrentis
Klebsiella granulomatis
Vibrio cholerae

Good penetration of skin –> Acne treatment (Minocycline)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Tetracyclines - Adverse effect

A

Discoloration of teeth and hypoplasia of the enamel in pregnant women and children under 8 years

Nephrotoxicity and Hepatotoxicity (increased risk in pregnant women) (Fatty degeneration)

Photosensitivity (Increased incidence in Doxycycline)
Erythema, sunburn

Dose-related nausea and vomiting (Tigecycline)

Nausea, vomiting, anorexia

Intestinal functional disturbances, anal pruritus, vaginal/oral candidiasis, Clostridium difficile associated colitis.

Renal tubular acidosis and other renal injury leads to nitrogen retention (outdated prepatarions)

IV: venous thrombosis
IM: local pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Tetracyclines - Interactions

A

Binds divalent and trivalent cations, including calcium, aluminium, and iron. For this reason, their oral bioavailability is reduced if they are taken with foods containing these ions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Tigecycline - Clinical use

A

Skin and soft tissue infections caused by MSSA and MRSA, E. coli,

Community-aquired pneumonia and complicated intraabdominal infections caused by various gram-positive and gram-negative organisms

Enterococcus fecalis, various streptococci, and Bacteroides fragilis

Multidrug-resistant strains of Acinetobacter,
Rickettsiae, Chlamydia sp., Legionella pneumophila, rapidly growing mycobacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Azithromycin, Clarithromycin - Clinical use

A

Respiratory infections by erythromycin sensitive bacteria, H. influenzae, M. catarrhalis,

Mycobacterium avium-intracellulare in patients with AIDS

Gonorrhea in combination with ceftriaxone

Toxoplasma gondii
Chlamydia
Sinusitis
Otitis media
Bronchitis

Azithromycin: campylobacter jejuni

Single-dose treatment for uncomplicated chlamydial urethritis (Clarithromycin)

Mycobacterium laprae (Clarithromycin)
Peptic ulcer disease from H. pylori (Clarithomycin)
20
Q

Azithromycin - Special considerations

A

Administered 1 h before or 2 h after meals

Aluminium and magnesium antacids delay absorption and reduce peak serum concentration

21
Q

Macrolides: Adverse effects

A
Stomatitis
Heart burn
Uncoordinated peristalsis
Nausea
Anorexia
Abdominal discomfort
Diarrhea

Erythomycin:
Tinnitus & impaired hearing
Thrombophlebitis
QT prolongation

Estolate: acute cholestatic hepatitis (fever, jaundice, impaired liver function). Allergic reactions (eosinophilia, rashes)

22
Q

Tetracyclines - Contraindications

A

Contraindicated for pregnant women and children <8 y

23
Q

Macrolides, Ketolides and Aminosugar - MoA

A

Binds to 50S ribosomal subunit and prevents peptide elongation and translocation from acceptor site to peptidyl site

24
Q

Macrolides

A

Azitromycin
Clarithromycin
Erythromycin (Base, stearate, estolate)

25
Q

Erythromycin - Clinical use

A

Gram-positive:
Corynebacterial infections (diphteria, erythrasma)
Sepsis
Resp., Neonatal, ocular, genital chlamydial infections and Community acquired pneumonia by pneumococcus
L. pneumophila, M. pneumoniae, Chlamydia pneumoniae

Mycobacteria (ex. Mycobacterium kansasii)

Gram-negative:
Neiserria sp, Rickettsia sp, Treponema pallidum, Campylobacter

Penicillin allergic patients (staph, strep. Pneumo)

Prophylaxis against endocarditis during dental procedures in patients with valvular heart disease

campylobacter jejuni

26
Q

Macrolides interactions

A

Erythromycin and clarithromycin inhibit cytochrome P450 3A4 and can elevate the plasma concentration of a large number of drugs metabolized by this isozyme. For example, concurrent administration of erythromycin or clarithromycin with carbamazepine can lead to life-threatening carbamazepine toxicity, and this combination should be avoided.

Erythomycin and clarithromycin also inhibit metabolism of lovastatin and simvastatin, and concurrent use of these statin drugs can lead to elevated statin levels and rhabdomyolysis.

27
Q

Ketolide

A

Telithromycin

28
Q

Telithromycin - Clinical use

A
Active in vitro against:
Streptococcus pyogenes
S pneumoniae
S aureus
H influenzae
Moraxella catarrhalis
Mycoplasma sp
L pneumophila
Chlamydia sp
H pylori
Neisseria gonorrhoeae 
Bacteroides fragilis
Toxoplasma gondii
certain nontuberculosis mycobacteria
29
Q

Telithromycin - Contraindications

A

Contraindicated for myasthenia gravis and for driving

30
Q

Telithromycin - Adverse effects

A
Diarrhea 
Nausea
Elevated liver enzymes
Severe liver toxicity (very rare)
Prolongation of QT
Resp failure in myasthenia gravis
Visual disturbances
Loss of conciousness
31
Q

Aminosugar antibiotic

A

Clindamycin

32
Q

Clindamycin - Clincal use

A
Bacteroides fragilis
Clostridium perfringes (the cause of gas gangrene).

MRSA and penicillin-resistant streptococci, including necrotizing fascittis
Skin and soft-tissue infections

Prophylaxis of endocarditis in patients with valvular heart disease

Pneumocystis jiroveci pneumonia in AIDS patients with primaquine

AIDS-related toxoplasmosis with pyrimethamine

Acne vulgaris

33
Q

Clindamycin - Adverse effects

A

Higher incidence of superinfections (clostridium) than other antibiotics

Severe diarrhea
Psuedomembranous colitis
Impaired liver function
Neutropenia

34
Q

Nitrobenzene antibiotic

A

Chloramphenicol

35
Q

Chloramphenicol - MoA

A

It binds reversibly to the 50S subunit of the bacterial ribosome and inhibits peptide bond formation

36
Q

Chloramphenicol - Clinical use

A

Broad-spectrum antibiotic that is active against pathogens causing meningitis, including pneumococci, meningococci, and H. influenzae

Salmonella
Bacteroides

Brain abcess

Rickettsiae (typhus, rocky mountain spotted fever)
Neiserria meningitidis

37
Q

Chloramphenicol - Special considerations

A

High concentrations in CNS
Lipophilic, well absorbed from gut

Partly metabolized by glucoronate conjugation (neonates obs)

38
Q

Chloramphenicol - Adverse effects

A

Gray baby syndrome characterized by cyanosis, weakness, respiratory depression, and shock

Reversible, dose-dependent anemia caused by blockade of iron incorporation into heme

Aplastic anemia (rare)

Nausea, vomiting, diarrhea,
Oral/vaginal candidiasis

39
Q

Streptogramin antibiotic

A

Quinupristin-Dalfopristin

40
Q

Quinupristin-Dalfopristin - MoA

A

Binds to 50S ribosomal subunit. Inhibits tRNA synthesis + inhibits peptidyl transferase

Inhibits protein synthesis when administered in 30:70.

41
Q

Quinupristin-Dalfopristin - Clinical use

A

Bactericidal against susceptible strains of staphylococci and streptococci but bacteriostatic against Enterococcus faecium

Active against many gram-postitive bacteria, including multidrug-resistant straphylococci, penicillin-resistant pneumococci, and vancomycin-resistant E. faecium, but not E. fecalis

Bacteremia
Pneumonia
Skin and soft tissue infections
Peritonitis
Endocarditis
Aortic graft infections
42
Q

Quinupristin-Dalfopristin - Adverse effects

A
Infusion site reactions
Arthralgia
Myalgia
Diarrhea
Nausea
43
Q

Linezolid - MoA

A

Binds to 23S ribosomal RNA of the 50S subunit, preventing formation of 70S initiation complex

44
Q

Linezolid - Clinical use

A

Active against aerobic gram-positive bacteria

Bactericidal against most strains of streptococci
Bacteriostatic against enterococci and staphylococci

Vancomycin-resistant E. faecium; pneumonia caused by methicillin-sensitive S. aureus and MRSA; and skin and soft tissue infections caused by methicillin-sensitive or methicillin-resistant staphylococci and Streptococcus pyogenes, or Steptococcus agalactiae

Given IV for serious infections such as necrotizing fasciits and pneumonia

Orally for mild to moderate skin and soft tissue infections

45
Q

Linezolid - Adverse effects

A

serotonin toxicity with fluoxetine
Thrombocytopenia
Anemia
Neutropenia in patients with renal insufficiency or during prolonged therapy

46
Q

Mupirocin - MoA

A

Competetive inhibition of isoleucine, preventing addition of isoleucine to protein

47
Q

Mupirocin - Clinical use

A

Active against gram-positive cocci, including most strains of methicillin-resistant staphylococci

Impetigo by streptococci and staphylococci

Nasal colonization of methicillin-resistant staphylococci