Antibiotics

Question 1

Streptomycin

Answer 1

Aminoglycoside (30S inhibitor)

Used for TB, second line treatment.

Question 2

Tobramycin

Answer 2

Aminoglycoside (30S inhibitor)

Used with gentamicin for Gm- organisms. Often used with beta-lactams

Question 3

Gentamicin

Answer 3

Aminoglycoside (30S inhibitor)

Used with tobramycin against Gm- organisms. Often used with beta-lactams.

Question 4

Amikcin

Answer 4

Aminoglycoside (30S inhibitor)

Used when there is resistance against tobramycin and gentamicin.

Question 5

Neomycin

Answer 5

Aminoglycoside (30S inhibitor)

For topical use.

Question 6

Kanamycin

Answer 6

Aminoglycoside (30S inhibitor)

For topical use only.

Question 7

Aminoglycoside

Answer 7

Binds to the 30S ribosome and blocks initiation, translocation, and causes mistranslation.
Usually bactericidal against Gm- bacteria.
Reversible nephrotoxicity and irreversible ototoxicity after about 5 days of use.

Question 8

Tetracyclines

Answer 8

Examples: tetracycline, oxytetracycline, demeclocycline, minocycline, doxycycline, tigecycline.
Bind to the 30S ribosome and interfere with protein synthesis by blocking the tRNA.
They chelate multitalent ions in the gut which impairs absorption.
Bacteriostatic against aerobic and anaerobic Gm+ and Gm- bacteria.
Good for rickettsia, STIs, respiratory infections, skin and soft tissue infections, MDR bacterial infections, anthrax, malaria and Lyme disease.
Cause GI disturbances, tooth discoloration when young, bone deformity when young, photo sensitization, and hepatoxicity

Question 9

Macrolides

Answer 9

Erythromycin, clarithromycin, Azithromycin, telithromycin
Bind to the 50S ribosome and block ribosomal translocation
Bacteriostatic against Gm+ and some Gm- bacteria.
Good for respiratory infections, skin and soft tissue infections, acute otitis media, strep pharyngitis, chlamydia, diphtheria, and pertussis.
Can cause GI disturbances and hepatotoxicity

Question 10

Lincosamide

Answer 10

Clindamycin
Binds to the 50S ribosome and interferes with ribosomal translocation.
Bacteriostatic against aerobic and anaerobic Gm+ bacteria.
Good for skin and soft tissue infections.
Can cause diarrhea, skin rashes and pseduomembranous colitis caused by C. difficile.

Question 11

Steptogramins

Answer 11

Quinupristin/Dalfopristin
Binds to the 50S ribosome and prevents translocation.
Active against most Gm+ bacteria. Bactericidal against strep and staph but bacteriostatic against enterococci
Good for vancomycin resistant E. faecium.
Can cause arthraligas and myalgia.

Question 12

Oxazolidinone

Answer 12

Linezolid
Binds to the 50S ribosome and blocks initiation.
Good against aerobic and anaerobic Gm+ bacteria.
Bactericidal against strep, bacteriostatic against staph and enterococci.
Good for infections caused by MDR Gm+ bacteria
Can cause myelosupression with 2 week + treatment

Question 13

Sulfonamides

Answer 13

Sulfisoxazole, sulfamethoxazole, sulfasalazine
Competitive antagonists against dihydropteroate synthase, anti-folate.
Bacteriostatic against Gm- and some Gm+ bacteria.
Good for UTIs and for ulcerative colitis and enteritis.
Can cause allergic reactions, cyrstalluria, and hematuria.

Question 14

Trimethoprim/sulfamethoxazole

Answer 14

TMP
Competitive antagonist against dihydrofolate reductase - anti-folate.
Bacteriostatic against many Gm- and some Gm+ bacteria.
Good for UTIs, pneumonia, shingellosis, salmonella infections, prostatitis, and acute exacerbation of bronchitis.
Can cause allergic reactions and anti folate effects (megaloblastic anemia)

Question 15

Floroquinolones

Answer 15

Ciprofloxacin, lomefloxacin, levofloxacin, ofloxacin, gemifloxacin, moxifloxacin.
Inhibit DNA gyrase (in Gm-) and topoisomerase IV (in Gm+)
Bactericidal
Good for UTIs, anthrax, diarrhea from Shigella, soft tissue, bone, and joint infections, intra abdominal infections, respiratory tract infections.
Can cause GI disturbances but are generally well tolerated.