9. Aminoglycosides are a group 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
10. Characteristics of Aminoglycosides:-
īĩ Formulations are Sulfate or hydrochloric salts
īĩ Formulations are water soluble and stable
īĩ Highly polar basic drugs.
īĩ Ionize during dissolution
īĩ Penetration through BBB is minimal
īĩ Least metabolized by hepatic enzymes
īĩ Excretion is mainly renal
11. īBactericidal in nature
īMore active in alkaline pH
īMOA is by interfering with protein synthesis
īAttach with 30S ribosomal subunit (ATT)
īMainly gram negative
īTherapeutic index is narrow
īNatural and semi-synthetic antibiotics
Characteristics of Aminoglycosides:-
15. Resistance against aminoglycosides
īĩ Development and synthesis of plasmid mediated bacterial
transferase enzyme, which inactivates Aminoglycosides.
īĩ Impaired active transport
īĩ Inactivating enzymes in the cell membrane & inactivate
Aminoglycosides
īĩ Aminoglycoside can not bind at target ribosomal subunit
and site.
īĩ Decreased affinity of ribosomal proteins for binding with
Aminoglycosides
33. Gentamicin
īĩ Broad spectrum
īĩ Most commonly used Aminoglycosides
īĩ Synergism with Beta lactams
īĩ Activity decreases in presence of pus
īĩ Use- Usually in combination with Penicillin, Cephalosporin
41. īĩ Neomycin is an aminoglycoside antibiotic found in
many topical medications such as creams, ointments,
and eyedrops.
īĩ Poorly absorbed in GIT
īĩ Excreted by the GIT.
Neomycin
42. Indication:-
īĩ Topical preparation used in:-
1. Infected wounds
2. Infected burns
3. Infected ulcers
4. Infected dermatosis
ī Oral preparation Used in:-
1. Surgery
2. Hepatic coma.
46. Amikacin
īĩ Semi-synthetic derivative of Kanamycin
īĩ Resistant is less
īĩ Widest spectrum
īĩ Reserve drug as alternate to Gentamicin
īĩ More hearing loss
50. Special concern in treatment:-
īĩ Tobramycin is superior to gentamicin for treatment of
P.aeruginosa .
īĩ Gentamicin is the preferred AGL used in combination treatment of
enterococcal endocarditis.
īĩ Streptomycin has the greatest activity of all the AGL against
M.tuberculosis.
īĩ Capreomycin is an AGL use as alternative drug to treat of
mycobacterial infection
īĩ Streptomycin & gentamicin are drugs of choice to treat tularemia
īĩ Streptomycin is drug of choice to treat plague & brucellosis
51. Patient counseling :
īĩ Do not take AGL if you are pregnant or could become pregnant during
treatment.
īĩ Do not take AGL if you are breast-feeding a baby.
īĩ Take each dose with a full glass of water.
īĩ Take AGL with food.
īĩ Store AGL at room temperature away from moisture, heat, and direct light.
52. 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