Drugs for the treatment of TB and other Respiratory Infections Flashcards
Inhibition of Cell wall synthesis
Penicillins Cephalosporins Vancomycin Bacitracin Isoniazid Ethambutol
Inhibition of Protein synthesis
Ainoglycosides
tetracylcines
Chloramphenicol
Macrolides
Disruption of cytoplasmic membrane
Polymyxins
Polyenes
Inhibition of general metabolic pathway
Sulfonamides
Trimethoprim
Dapsone
Inhibition of DNA or RNA synthesis
Actinomycin
Nucleotide analogs
quinolones
rifampin
Inhibition of pathogen’s attachment to or recognition of host
Arildone
Pleconaril
treatment is based on the signs and symptoms in the involved organ system
Empiric therapy
Pharyngitis/Tonsilitis
Exudative or diffuse erythema (associated cough, rhinorrhea, hoarseness and/or ulcers suggest viral etiology) -no antibiotic
Herpes simplex
fever, irritability, pain upon swallowing, and regional lymphadenopathy
treatment is supportive and symptomatic
For immune-compromised and severe disease: acyclovir
Coxsackie A9, B-15, ECHO, Enterovirus 71
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
Oral candidiasis
nystatin or miconazole gel
Bacterial Pharyngitis/Tonsilitis
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)
Membranous pharyngitis due to diphtheria
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
Gonococcal Pharyngitis
3rd generation cephalosporin: Ceftriaxone
<45kg : 125 mg single dose IM
>45 kg: 250 mg single dose IM
Most common cause of Acute OtitisMedia
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)
Most imprtant etiology of bronchiolitis
RSV
Ribavirin
CAP in neonates
G(-) Bacilli
Ampicillin + aminoglycosides is given
PCAP A guidelines
Co-amoxiclav is already recommended
Ideal TB drug
Can penetrate the mycolic acid layer and arabinogalactan layer
Can kill all kinds of TB whether dormant or active
Can immediately go to macrophages
First line TB drugs
INH RIFAMPICIN PYRAZINAMIDE ETHAMBUTOL STREPTOMYCIN
Prodrug activated by catalase-peroxidase hemoprotein, KatG
Isoniazed (Isonicotinic acid hydrazide)
High Early bactericidal activity that kills actively growing bacteria
Isoniazid
-rapid decrease in sputum bacilli for the first 2 weeks then slow down for non-growing bacterial populations
Bactericidal against actively growing MTB, both intracellular and extracellular
ISONIAZID
-Bacteriostatic against dormant organisms
INH KINETICS
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
ADverse effects of INH
Direct toxicity (Hepatic, peripheral, seiures, Hemolytic anemia)
Immunologic reactions (Fever and rash, Drug induced SLE)
Antidote to INH
Vitamin B6
Inhibits bacterial RNA synthesis by binding to the beta subunit of the DNA-dependent RNA polymerase, blocking RNA transcription
Rifampicin
-Semisynthetic derivative of rifamycon B, produce by amycolaptopssiis mediterrnei
Bactericidal against rapidly proliferating MTB and against intracellular slow growing bacilli, also active against some g(+) and (-) organisms
Rifampicin
-Not to be used as monotherapy for other bacterial infections
Rifampicin Kinetics
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
ADverse effect of Rifampicin
Hepatotoxic, Hypersensitivity reactions Orange color of body fluids Hematologic abnormalities (Thrombocytopenia, HA)
Wonder Drug that reduced treatment time of TB
Pyrazinamide
-synthetic analog of nicotinamide
Bactericidal for tubercle bacilli in acid pH - intracellular in monocytes/marophages
Pyranizamide
Important sterilizing agent active against residual intracellular organisms which can cause relapse
Pyranizamide
Pyranizamide Kinetics
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
Adverse effect of Pyranizamide
Hepatotoxicity
HyperUricemia
Allergic Reactions
Inhibits the snthesis of arabinoglycan by inhibiting arabinosyl transferase
Ethambutol
Bacteriostatic in macrophages and active against large populations of bacilli in cavities
Ethambutol
Ethambutol Kinetics
A: Well absorbed from the gut
D: CSF concentration increases with inflamed meninges
M: Partially metabolized in the liver
E: Feces and urine
Aminoglycoside, BActericidal against MTB in vitro, Activity limited to extracellular bacteria
Streptomycin
Streptomycin Kinetics
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
