The presentation covers aminoglycoside antibiotics, detailing their mechanism of action, pharmacokinetics, classifications, and side effects. It highlights key members such as streptomycin, gentamicin, neomycin, kanamycin, and amikacin, along with their uses and contraindications. The document also discusses resistance mechanisms and provides patient counseling guidelines.
Aminoglycosides are agroup of antibiotics that are
effective against:
Aminoglycoside
(AGL)
Aerobic gram( - )bacteria
e.g.: pseudomonas,
Acinetobacter,
enterobacter
Some mycobacteria
e.g.:
bacteria that cause
tuberculosis
Some gram ( + ) bacteria
9.
Characteristics of Aminoglycosides:-
Formulations are Sulfate or hydrochloric salts
Formulations are water soluble and stable
Highly polar basic drugs.
Ionize during dissolution
Penetration through BBB is minimal
Least metabolized by hepatic enzymes
Excretion is mainly renal
10.
Bactericidal in nature
Moreactive in alkaline pH
MOA is by interfering with protein synthesis
Attach with 30S ribosomal subunit (ATT)
Mainly gram negative
Therapeutic index is narrow
Natural and semi-synthetic antibiotics
Characteristics of Aminoglycosides:-
Resistance against aminoglycosides
Development and synthesis of plasmid mediated bacterial
transferase enzyme, which inactivates Aminoglycosides.
Impaired active transport
Inactivating enzymes in the cell membrane & inactivate
Aminoglycosides
Aminoglycoside can not bind at target ribosomal subunit
and site.
Decreased affinity of ribosomal proteins for binding with
Aminoglycosides
Gentamicin
Broad spectrum
Most commonly used Aminoglycosides
Synergism with Beta lactams
Activity decreases in presence of pus
Use- Usually in combination with Penicillin, Cephalosporin
Neomycin isan aminoglycoside antibiotic found in
many topical medications such as creams, ointments,
and eyedrops.
Poorly absorbed in GIT
Excreted by the GIT.
Neomycin
Special concern intreatment:-
Tobramycin is superior to gentamicin for treatment of
P.aeruginosa .
Gentamicin is the preferred AGL used in combination treatment of
enterococcal endocarditis.
Streptomycin has the greatest activity of all the AGL against
M.tuberculosis.
Capreomycin is an AGL use as alternative drug to treat of
mycobacterial infection
Streptomycin & gentamicin are drugs of choice to treat tularemia
Streptomycin is drug of choice to treat plague & brucellosis
50.
Patient counseling :
Do not take AGL if you are pregnant or could become pregnant during
treatment.
Do not take AGL if you are breast-feeding a baby.
Take each dose with a full glass of water.
Take AGL with food.
Store AGL at room temperature away from moisture, heat, and direct light.
51.
Available dosage form
(all aminoglycosides have very poor
absorption from G.I.T )
Dose regimen
(if creatinine clerance > 90ml/min)
Drug
I.V , I.MI.V
25-30 mg/weak ( tuberculosis )Streptomycin
OralOral
500 mgParomomycin
Oral , topical
It is not given intravenously, as it is extremely
nephrotoxic
Oral
For hepatic encephalopathy :
4-12 gm/d
As prophylactic in GI surgery :
1.0 gm po x3 with erythromycin
Neomycin
I.V , I.M , inhalationI.V
5.1 ( if critically ill ) mg/kg q24hTobramycin
I.V , I.M , Topical
I.V
5.1 ( if critically ill ) mg/kg q24hGentamicin
I.V , I.M
I.V
15mg/kg q24hAmikacin
I.V , I.M
The lowest ototoxic AGL
I.V
6.5 mg/kg q24hNetilmicin