antibiotics

Question 1

Beta-lactam compounds

Answer 1

penicillins,cephalosporins,monobactams ,carbapenems and Beta lactamase inhibitors .

Question 2

classification of penicillins

Answer 2

1.penicillins like penicillin G are active against G+ organisms,G- cocci and non beta lactamase producing anerobes.2.Antistaphylococcal penicillins eg nafcillin are resistant to staphylococcal beta lactamases.they are active against staph and strep.3.Extended spectrum penicillins eg.ampicillin.penicillins and extended spectrum penicillins are susceptible to hydrolysis by beta lactamases

Question 3

classification of penicillins

Answer 3

1.penicillins like penicillin G are active against G+ organisms,G- cocci and non beta lactamase producing anerobes.2.Antistaphylococcal penicillins eg nafcillin are resistant to staphylococcal beta lactamases.they are active against staph and strep.3.Extended spectrum penicillins eg.ampicillin.penicillins and extended spectrum penicillins are susceptible to hydrolysis by beta lactamases

Question 4

penicillin v vs penicillin G

Answer 4

is acid stable and G is acid labile.

Question 5

MOA of penicillins

Answer 5

inhibit cell wall synthesis. They are bactericidal.

Question 6

resistance mechanisms to penicillins

Answer 6

(1).inacativation of antibiotic by beta lactamase.(2).modification of target PBPs .(3) impaired penetration of drug and (4).efflux.

Question 7

acid stable penicillins

Answer 7

dicloxacillin,ampicillin and amoxicillin.

Question 8

clinical uses of penicillin

Answer 8

penicillin G is the DOC in the rx of infections caused by streptococci,meningococci ,enterococci ,non beta lactamase producing staph.

Question 9

CEPHALOSPORINS AND CEPHAMYCINS.

Answer 9

not active against enterococci and L.monocytogenes

Question 10

first generation

Answer 10

cefazolin,cephalexin,cefadroxil ,cephalothin .They are active against G+cocci.Used for treatment of UTIs ,soft tissue abscess

Question 11

2nd generation

Answer 11

cefaclor ,cefamandole,cefuroxime,cefprozil.active against H influenza

Question 12

3rd generation

Answer 12

cefoperazone ,cefotaxime,ceftriaxone,cefixime

Question 13

Monobactams

Answer 13

active against aerobic gram negative rods eg Aztreonam

Question 14

beta lactamse inhibitors

Answer 14

clavulanic acid,sulbactam and tazobactam

Question 15

CARBAPENEMS

Answer 15

Doripenem,ertapenem,imipenem and meropenem

Question 16

imipenem

Answer 16

active against G- rods eg p aeruginosa,G+ organisms and anaerobes.

Question 17

GLYCOPEPTIDE INHIBITORS

Answer 17

vancomycin-inhibits cell wall synthesis by inhiting cross -linkage between peptidoglycan layers.Its is active against G+ bacteria.BactericidalUsed to treat sepsis or endocarditis caused by methicillin resistant staphylococci.Its is synergistic with gentamicin

Question 18

teicoplanin

Answer 18

similar to vancomycin

Question 19

PROTEIN SYNTHESIS INHIBITORS

Answer 19

tetracyclines,macrolides,lincosamides,chloramphenicol,streptogramins and oxazolidinones.

Question 20

Tetracyclines

Answer 20

are active against G+ and G- bacteria including anaerobes,rickettsiae,chlamydiae,mycoplasmas and some protozoa.

Question 21

MOA

Answer 21

bind reversibly to the 30S subunit of the bacterial ribosome.block aminoacyl t-RNA from binding to the mRNA -ribosome complex therefore blocking the addition of amonno acids to the growing polypeptide.

Question 22

examples

Answer 22

doxycycline,tigecycline(glycylcycline),minocycline,methacycline

Question 23

clinical uses

Answer 23

DOC in the rx of mycoplasma pneumoniae ,chlamydiae,rickettsiae and some spirochetes.

Question 24

adverse effects

Answer 24

1they are readily bound to calcium deposited in newly formed teeth and bone so may damage bones amd teeth.2.liver toxixcity.3.photosensitivity

Question 25

MACROLIDES

Answer 25

prototype drug is erythromycin .clarithromycin and azythromycin are semisynthetic derivatives of the prototype.

Question 26

erythromycin

Answer 26

active against G+ organisms and some G-

Question 27

MOA

Answer 27

binds to the 50S ribosomal RNA.resistance mechanisms 1.efflux2.modification of ribosomal binding site.

Question 28

pk

Answer 28

must be administered with enteric coating

Question 29

clarithromycin

Answer 29

active against toxoplasma gondii ,Mycobacterium avium

Question 30

LINCOSAMIDES

Answer 30

clindamycin,lincomycin

Question 31

spectrum.

Answer 31

active against streptococci,staph and pneumococci. No activity against aerobic organisms.

Question 32

Moa

Answer 32

binds to the 50s subunit inhibit peptidyl transferase activity hence blocking ptotein elongation.

Question 33

uses

Answer 33

rx of skin and soft tissue infections

Question 34

chloramphenical

Answer 34

binds to the 50s subunit and inhibits peptidyl transferassle.It is bacteriostatic and active against both aerobic and anaerobic G+ and G- organisms and rickettsiae but not chlamydiae

Question 35

Uses

Answer 35

treatment of typhus and Rocky mountain spotted fever.

Question 36

Adverse effects

Answer 36

Aplastic anaemia.2Gray baby syndrome

Question 37

Streptogramins

Answer 37

Quinupristin -dalfopristin.Active against G+ cocci.Inhibit protein synthesis by 8rreversibly blocking ribosome functioning.

Question 38

OXAZOLIDINONES

Answer 38

linezolid is active against G+ organisms,anerobic cocci G+.primarily bacteriostatic but bactericidal to streptococci.

Question 39

MOA

Answer 39

prevents formation of ribosome complex that initiates protein synthesis.Its binding site 23s ribosomal RNA of the 50 S subunit .

Question 40

BACTETICIDAL INHIBITORS OF PROTEIN SYNTHESIS

Answer 40

Aminoglycosides and spectinomycin

Question 41

Aminoglycosides

Answer 41

streptomycin,neomycin,kanamycin,gentamycin,amikacin,tobramycin.active against G- enteric bacteria.

Question 42

MOA

Answer 42

irrevesible inhibition of protein synthesis.they bind to the 30s subunitThey have concentartion dependent killing

Question 43

Adverse effects

Answer 43

ototoxicity and nephrotocicity

Question 44

streptomycin used in treatment of

Answer 44

mycobacterial infections,nontuberculous infections

Question 45

spectinomycin

Answer 45

structurally related to aminoglycosides but lacks amino sugars and glycosilic bonds.used in treatment of for drug resistant gonorrhea

Question 46

ANTIFOLATE DRUGS

Answer 46

sulfonamides,trimethoprim and quinolones

Question 47

sulfonamides

Answer 47

structurally similar to PABA.Active against G+ and G- bacteria

Question 48

Moa

Answer 48

they inhibit dihydropteroate synthetase and folate production.

Question 49

uses

Answer 49

used in combination of trimethoprim-sulfamethoxazole to treat pneumocystis jiroveci.sulfudiazine is used topically to prevent infection of burn wounds.

Question 50

adverse effects

Answer 50

steven johnson syndrome

Question 51

Trimethoprim and trimethoprim sulfamethoxazole mixtures and pyrimethamine.

Answer 51

inhibits dihydrofolate reductase

Question 52

DNA GYRASE INHIBITORS

Answer 52

Fluoroquinolones-block DNA gyrase and topoisomerase 4

Question 53

examples

Answer 53

ciprofloxacin,levofloxacin,norfloxacin

Question 54

active against

Answer 54

G- aerobic bacteria

Question 55

uses

Answer 55

UTIs

Question 56

DRUGS USED IN TUBERCULOSIS

Answer 56

isoniazid,rifampin,pyrazinamide,ethambutol and streptomycin-first line treatment

Question 57

Isoniazid

Answer 57

inhibits synthesis of mycolic acids

Question 58

Rifampin

Answer 58

active against G+ and G- cocci,mycobacteria.It inhibits RNA synthesis.It induces most CYP450

Question 59

Adverse effects

Answer 59

imparts an orange color to urine,sweat,tears amd contact lenses.

Question 60

Ethambutol

Answer 60

active against mycobacterium tuberculosis

Question 61

Ethambutol

Answer 61

active against mycobacterium tuberculosis

Question 62

pyrazinamide(PZA)

Answer 62

it is taken up by macrophages and exerts its activity against mycobacteria residing within the acidic environment of lysosomes.

Question 63

2nd line drugs

Answer 63

amikacin,capreomycin,cyprofloxacin,rifabutin,rifapentine,levofloxacin,ethionamide and cycloserine.

Question 64

drugs used in leprocy

Answer 64

dapsone-inhibits folate synthesis