Antibiotics

Question 1

How is meningitis treated?

Answer 1

1) neonates cefotaxime
Ampicillin-Gentamycin (Listeria)
2) adults ceftriaxone
Allergy: Chloramphenicol
3) Meningococcal Carrier State: Rifampin/ Minocycline

Question 2

Antibiotics causing Hemolysis in G6PD deficiency

Answer 2

Sulfonamides, Isonhiazid

Question 3

Which Bugs are not covered by Carbapenems?

Answer 3

MRSA
Some Pseudomonas
Mycoplasma

Question 4

Which Protein Synthesis inhibitors are bactericidal?

Answer 4

Aminoglycosides ( Misreading due to 30S subunit initiation binding)

Ketolides=Killers (telithromycin)

Question 5

Treatment of gonorrhea

Answer 5

1) Ceftriaxone/ Azithromycin ( one dose) or Doxycycline for 1 week (cover chlammydia)
2) Spectinomycin ( cef. Resistant species)/ Doxycycline

Question 6

How is Red Man Syndrome treated?

Answer 6

RMS= Histamine Release due to vancomycin HR. Slow infusion and diphenhydramine (H1 antagonist) administration

Question 7

How is osteomyelitis treated?

Answer 7

S.AUREUS: clindamycin

Gram(-) Ciprofloxacin

Question 8

Which cephalosporins are associated with disulfiram like effect?

Answer 8

The -azole like: Cefamandole Cefoperazone Cefotetan

Mnemonic: Family Permission for Tea

Question 9

Which antibiotics are most associated with Cl. Difficile Ps.Colitis?

Answer 9

Clindamycin Ampicillin Quinolones Metronidazole most common

Question 10

How is Chloramphenicol metabolized?

Answer 10

-phen- = lipid-soluble. Antagonizes with bilirubin for glucuronidation. Should not be used in pregnancy and neonates due to agray Baby syndrome. Sulfonamides also displace bilirubin from albumin and should be avoided ( Kernicterus risk)

Question 11

Which antibiotics are involved in P450 metabolism?

Answer 11

Macrolides inhibit P450 (except Azithromycin)
Quinolones also inhibit 1CA2 ( adjust the dose of TCAs (imipramine) Atypical Antipsychotics, Theophylline(two))
Streptogramins inhibit (qunupristine/ dalfopristine)
Rifampin induces P450

Question 12

Which infections should not be treated with daptomycin?

Answer 12

Respiratory ( surfactant inhibits daptomycin)

Question 13

Which antibiotic is associated with seizures?

Answer 13

Imipenem. Rem. it is clad ministered with cilastatin to increase its half- life ( dehydripteridase inhibitor)
On the other hand, amino glycosides are administered with probenecid (blocks weak acid pumps to increase their half life)

Isoniazid also depletes B6 and decreases GABA synthesis increasing the risk of anxiety and seizures

Question 14

Tetracyclines should be taken with food?

Answer 14

Never! They act as chelators and are poorly absorbed. Due to their chelating properties the patient must not take antacids ( contain Al, Mg)

Question 15

Which antibiotics may cause respiratory paralysis?

Answer 15

Aminoglycosides (Rare)

Telithromycin in myasthenia Gravis patients

Question 16

How is aspiration pneumonia treated?

Answer 16

Clindamycin ( anaerobes above diaphragm)

Question 17

Which cephalosporins cover anaerobes?

Answer 17

Cefoxitine Cefmetazole Cefotetan ( a Fox Met Bacteroides for Tea)

Question 18

How is Endicarditis treated?

Answer 18

1) Bacterial: amp/gent

2) Fungal (IV drug users): Amphotericin B/ Flucytosine

Question 19

Home treatment for MRSA?

Answer 19

Linezolid ( available P.O.)

Question 20

Cl. Difficile treatment?

Answer 20

1. Metronidazole
2. Vancomycin
3. Fidaxomycin

Question 21

Which antibiotics inhibit translocation?

Answer 21

Metro Closed! Macrolides Clindamycin bind to P site in 50S subunit

Question 22

1st generation cephalosporins?

Answer 22

-ph- , cefazol, cefadroxil

Question 23

Antibiotic Rashes?

Answer 23

1. Penicillins (HR I or HR IV=Erythema Multiforme)
2. Vancomycin (Red Man Syndrome)
3. Tetracyclines photo toxic dermatitis (καφεκίτρινο χρώμα)
4. Quinolones (blackish, think of it to connect it with B. Anthracis treatment)
5. Neomycin

Question 24

Amino glycosides and sulfonamides main mode of resistance?

Answer 24

Conjugation by acetylases for aminoglycosides
Sulfonamides: DP Synthase point mutation
Drug effluent pumps
S.Aureus only: incr PABA production
Vancomycin: Change of d-ala/d-ala to d-all/d-LAC

Question 25

Ethambutol main side effect?

Answer 25

Inhibits arabidogalactan formation ( arabinosyltransferase inhibitor) so (free galactol increased) causes optic neuritis. Blurry vision/ red green vision loss
All other anti-TB are hepatotoxic