Drugs for the treatment of TB and other Respiratory Infections

Question 1

Inhibition of Cell wall synthesis

Answer 1

Penicillins
Cephalosporins
Vancomycin
Bacitracin
Isoniazid
Ethambutol

Question 2

Inhibition of Protein synthesis

Answer 2

Ainoglycosides
tetracylcines
Chloramphenicol
Macrolides

Question 3

Disruption of cytoplasmic membrane

Answer 3

Polymyxins

Polyenes

Question 4

Inhibition of general metabolic pathway

Answer 4

Sulfonamides
Trimethoprim
Dapsone

Question 5

Inhibition of DNA or RNA synthesis

Answer 5

Actinomycin
Nucleotide analogs
quinolones
rifampin

Question 6

Inhibition of pathogen’s attachment to or recognition of host

Answer 6

Arildone

Pleconaril

Question 7

treatment is based on the signs and symptoms in the involved organ system

Answer 7

Empiric therapy

Question 8

Pharyngitis/Tonsilitis

Answer 8

Exudative or diffuse erythema (associated cough, rhinorrhea, hoarseness and/or ulcers suggest viral etiology) -no antibiotic

Question 9

Herpes simplex

Answer 9

fever, irritability, pain upon swallowing, and regional lymphadenopathy

treatment is supportive and symptomatic

For immune-compromised and severe disease: acyclovir

Question 10

Coxsackie A9, B-15, ECHO, Enterovirus 71

Answer 10

Herpangina - acute onset, fever, irritabilitu, a sore mouth, malaise, and difficulty eating

Vesicles develop on the posterior soft palate, tonsils and oropharynx

treatmet is supportive (no antiviral) - pain and fever management

Question 11

Oral candidiasis

Answer 11

nystatin or miconazole gel

Question 12

Bacterial Pharyngitis/Tonsilitis

Answer 12

Group A, C, G strep.

Ideally penicillin VK
(alternative: Amoxicillin give for 10 days)

Benzathine Pen G (Oily, single dose is equal to 2 weeks of oral penicillin)

Question 13

Membranous pharyngitis due to diphtheria

Answer 13

C. diphtheria (human to human)
C. ulcerans
C. pseudotuberculosis (animal to human)

Diphtheria antitoxin (do scratch test before therapy)
Dose depends on stage of illness 

48 hours: 20000-40000
NP membrane: 40000-60000
>3days plus bull neck: 80000-120000

Pen G
Phenoxymethylpenicillin

Question 14

Gonococcal Pharyngitis

Answer 14

3rd generation cephalosporin: Ceftriaxone
<45kg : 125 mg single dose IM
>45 kg: 250 mg single dose IM

Question 15

Most common cause of Acute OtitisMedia

Answer 15

H. Influenza and S. pneumoniae

Treat children <2 y.o
if >2 y.o afebrile, no ear pain, neg./questionable exam - consider analgesic treatment without antimicrobials

Usual dose: 40-60 mg/day
Amoxicillin 80-90 mg/kg/day div q12 x10d (<2 y.o) 7d (2-5), 5-7d (>6yo)

Question 16

Most imprtant etiology of bronchiolitis

Answer 16

RSV

Ribavirin

Question 17

CAP in neonates

Answer 17

G(-) Bacilli

Ampicillin + aminoglycosides is given

Question 18

PCAP A guidelines

Answer 18

Co-amoxiclav is already recommended

Question 19

Ideal TB drug

Answer 19

Can penetrate the mycolic acid layer and arabinogalactan layer

Can kill all kinds of TB whether dormant or active

Can immediately go to macrophages

Question 20

First line TB drugs

Answer 20

INH
RIFAMPICIN
PYRAZINAMIDE
ETHAMBUTOL
STREPTOMYCIN

Question 21

Prodrug activated by catalase-peroxidase hemoprotein, KatG

Answer 21

Isoniazed (Isonicotinic acid hydrazide)

Question 22

High Early bactericidal activity that kills actively growing bacteria

Answer 22

Isoniazid

-rapid decrease in sputum bacilli for the first 2 weeks then slow down for non-growing bacterial populations

Question 23

Bactericidal against actively growing MTB, both intracellular and extracellular

Answer 23

ISONIAZID

-Bacteriostatic against dormant organisms

Question 24

INH KINETICS

Answer 24

A : Readily absorbed from GIT, Must be taken on an empty stomach

D: Diffuses well into all body fluids and tissues, CSF conc. 20-100% of serum, Penetrates well into caseous TB lesions)

M: NAT2 gene, Filipinos are rapid acetylators

E: Renal as unchanged drug

Question 25

ADverse effects of INH

Answer 25

Direct toxicity (Hepatic, peripheral, seiures, Hemolytic anemia) Immunologic reactions (Fever and rash, Drug induced SLE)

Question 26

Antidote to INH

Answer 26

Vitamin B6

Question 27

Inhibits bacterial RNA synthesis by binding to the beta subunit of the DNA-dependent RNA polymerase, blocking RNA transcription

Answer 27

Rifampicin -Semisynthetic derivative of rifamycon B, produce by amycolaptopssiis mediterrnei

Question 28

Bactericidal against rapidly proliferating MTB and against intracellular slow growing bacilli, also active against some g(+) and (-) organisms

Answer 28

Rifampicin -Not to be used as monotherapy for other bacterial infections

Question 29

Rifampicin Kinetics

Answer 29

A: Well absorbed orally, undergoes enterohepatic circulation; must be taken on an empty stomach D: Highly lipophilic, crosses BBB M: Deacetylated, metabolite has antibacterial activity E: Bile and Urine

Question 30

ADverse effect of Rifampicin

Answer 30

``` Hepatotoxic, Hypersensitivity reactions Orange color of body fluids Hematologic abnormalities (Thrombocytopenia, HA) ```

Question 31

Wonder Drug that reduced treatment time of TB

Answer 31

Pyrazinamide -synthetic analog of nicotinamide

Question 32

Bactericidal for tubercle bacilli in acid pH - intracellular in monocytes/marophages

Answer 32

Pyranizamide

Question 33

Important sterilizing agent active against residual intracellular organisms which can cause relapse

Answer 33

Pyranizamide

Question 34

Pyranizamide Kinetics

Answer 34

A: Well absorbed from the GIT D: Widely distributed in body tissues including CNS, lung and liver M: Hepatic, half life is 8-11 hours E: Renal

Question 35

Adverse effect of Pyranizamide

Answer 35

Hepatotoxicity HyperUricemia Allergic Reactions

Question 36

Inhibits the snthesis of arabinoglycan by inhibiting arabinosyl transferase

Answer 36

Ethambutol

Question 37

Bacteriostatic in macrophages and active against large populations of bacilli in cavities

Answer 37

Ethambutol

Question 38

Ethambutol Kinetics

Answer 38

A: Well absorbed from the gut D: CSF concentration increases with inflamed meninges M: Partially metabolized in the liver E: Feces and urine

Question 39

Aminoglycoside, BActericidal against MTB in vitro, Activity limited to extracellular bacteria

Answer 39

Streptomycin

Question 40

Streptomycin Kinetics

Answer 40

A: Poor, not given orally, Given only in IM or IV D: Distribute into the most body fluids except the brain; therapeutics concentrations may pass in inflamed meninges E: Renal