Antibiotics

Question 1

Aminoglycoside names and related toxicity

Answer 1

-Gentamicin and streptomycin–>ototoxic

Neomycin
Nephrotoxic
Ototoxic
Neuromuscular blockers
‘
Teratogenic**

Question 2

Aminoglycoside pathogenesis
-Mutation?

Answer 2

-Needs energy to get inside cell,work better in GRAM- aerobic bacteria (thinner wall and has energy).
-Binds irriversible to 30S subunit, depending on concentration is Bacteriocidal or Bacteriostatic.

-Pumps

Question 3

What other drug helps efficacy of Aminoglycosides?
-Used?

Answer 3

-Beta lactam–>destroy cell wall and promote entry.
-**Used:Infective Endocartitis with Enteroccoci. **

Question 4

What drug giving together with Gentamycin + Streptomycin will worsen toxcicity?

Answer 4

-Loop Diuretics (ototoxicity).

Question 5

What drugs if given with Neomycin will worsen toxicity?

Answer 5

-Amphotericin B, Cisplatin, Vancomycin

Question 6

Fluoroquinolones names

Answer 6

-Ciprofloxacin, Ofloxacin,Levofloxacin..

Question 7

Fluoroquinolone mechanism action

Answer 7

-Inhibit Topoisomerase 2 and Top.4–>Bactericidal.
-Mayorly used for UTI (commonest is GRAM-)

Question 8

A.E Fluoroquinolones:

Answer 8

-Damages cartilage (pregnancy and <18 don’t give), Tensonitis (athletes, >60 yrs.)
-Also during breasfeeding

Question 9

Ciprofloxacin type of drug and Cyt inhb.?

Answer 9

-Cyt P450 inhb. and Fluoroquinolone.

Question 10

How do you get resistance towards Fluoroquinolones

Answer 10

-Topoisomeras mutations.

Question 11

-Praziquantel use for?
and mechanism action?

Answer 11

-Praziquantel (Incr. Ca2+ permeability, Incr. vacuolization)
- Helminths infections (T.Soleum and Schistosoma–>bladder cancer)

Question 12

Nystatin

Answer 12

-Same as amphotericin B.Topical use only as to otoxic for systemic use or oral candidiasis (thrush); topica for diaper rash or vaginal candidiasis.

Question 13

Vancomycin mechanism action
-Toxicity

Answer 13

-By-passes acting on PBP,therfeore mutation will not affect it.
-Acts on Glycoproteins chains–>prevents linkage by PBP.
-Nephrotoxic, and vancomycin reaction (massive flushing)

Question 14

How do you prevent vancomycin infusion reaction?

Answer 14

-Give **ANTI-Histamine. **

Question 15

Disulfiram reaction ass with what drug and what it is?

Answer 15

Chephalosporins ,1* generation sulfonylureas, Procarbazine, Griseofulvin and Metronidazole

when you use alcohol with chephalosporin–>nausea,flushing and tachycardia.

Question 16

Sulfonamides (Sulfamethoxazole) mechanism and A.E?

Answer 16

-Binds to bacteria Dihydropteroate Synthase (decr THF=Folate–>needed for DNA synthesis)
-A.E Hemolytic anemia G6PD defc.Photosensitivity,displaces warfarin from albumin,P450 inhb.

Question 17

Trimethropin actions and A.E?

Answer 17

-Inhb DihydroFolate Reductase
-Used:UTI’s, Shigella<Pneumocystis Jirovecci,Toxoplasmoxis prophylaxis,MRSA.
A.E:Bone Marrow supression–>**Pancytopenia **(megaloblastic anemia),Teratogenic

Question 18

What drug you give to avoid A.E of Trimetropin?

Answer 18

Leucovorin (Folic acid)

Question 19

SMX-TMP are and why

Answer 19

-Synergistic and both inhibit folate synthesis.

Question 20

Macrolides

Answer 20

Clarithromycin,Erythromycin,Azithromycin
-Binds 50S REVERISBLY (BACTERIOSTATIC)–>Blocking translocations.
-Resitance:Efflux proteins.
Erytromycin and Clarithromycin:P450 inhb.

Question 21

antibiotics that contraindicated in pregnancy?

Answer 21

tetracyclines Aminoglycosides Fluoroquinolones

Give macrolides or doxycycline

Question 22

Treats anaerobic infections above the diaphragm.
Anaerobic infections (eg,Bacteroides spp.,Clostridium perfringens)

AE:Pseudomembranous colitis (C difficile overgrowth),fever,diarrhea

Answer 22

Clindamycin
-Blocks peptide transfer (translocation) at 50S ribosomal subunit. Bacteriostatic.

Question 23

What drug is ineffective against mycolic acid bacteria?

Answer 23

-Beta lactam, this bacteria have NO cell wall.