Drug
Information




Gentamicin

Pharmacokinetics

Gentamicin and other aminoglycosides are poorly absorbed from the
gastrointestinal tract but are rapidly absorbed after intramuscular
injection. Average peak plasma concentrations of about 4 micrograms per
mL have been attained in patients with normal renal function 30 to 60
minutes after intramuscular administration of a dose equivalent to 1 mg
of gentamicin per kg body-weight, which is similar to concentrations
achieved after intravenous infusion. There may be considerable
individual variation. Several doses are required before plasma
equilibrium concentrations occur and this may represent the saturation
of binding sites in body tissues such as the kidney. Binding of
gentamicin to plasma proteins is usually low.
Following parenteral administration gentamicin and other aminoglycosides
diffuse mainly into extracellular fluids. However, there is little
diffusion into the CSF and even when the meninges are inflamed effective
concentrations may not be achieved; diffusion into the eye is also poor.
Aminoglycosides diffuse readily into the perilymph of the inner ear.
They cross the placenta but only small amounts have been reported in
breast milk.
Systemic absorption of gentamicin and other aminoglycosides has been
reported after topical use on denuded skin and burns and following
instillation into, and irrigation of, wounds, body-cavities, and joints,
but not the urinary bladder.
The plasma elimination half-life for gentamicin has been reported to be
2 to 3 hours though it may be considerably longer in neonates and
patients with renal impairment. Gentamicin and other aminoglycosides do
not appear to be metabolised and are excreted virtually unchanged in the
urine by glomerular filtration. At steady-state at least 70% of a dose
may be recovered in the urine in 24 hours and urine concentrations in
excess of 100 micrograms per mL may be achieved. However, gentamicin and
the other aminoglycosides appear to accumulate in body tissues to some
extent, mainly in the kidney, although the relative degree to which this
occurs may vary with different aminoglycosides. Release from these sites
is slow and small amounts of aminoglycosides may be detected in the
urine for up to 20 days or more after administration ceases. Small
amounts of gentamicin appear in the bile.
The pharmacokinetics of the aminoglycosides are affected by many
factors, which may become significant because of the relatively small
difference between therapeutic and toxic concentrations, reinforcing the
need for monitoring. Absorption from intramuscular sites may be reduced
in critically-ill patients, especially in conditions that reduce
perfusion such as shock. Plasma concentrations may also be reduced in
patients with conditions which expand extracellular fluid volume or
increase renal clearance including ascites, cirrhosis, heart failure,
malnutrition, spinal cord injury, burns, cystic fibrosis, and possibly
leukaemia. Clearance is also reportedly increased in intravenous drug
abusers, and in patients who are febrile. In contrast, renal impairment
or reduced renal clearance for any reason (for example in neonates with
immature renal function, or in the elderly in whom glomerular function
tends to decline with age) can result in markedly increased plasma
concentrations and/or prolonged half-lives (although in neonates initial
plasma concentrations may actually be reduced, due to a larger volume of
distribution). Plasma concentrations may also be higher than expected
for a given dose in obese patients (in whom extracellular volume is
lower, relative to weight), and in patients with anaemia.
Renal clearance, and hence plasma concentrations, of aminoglycosides may
vary according to a circadian cycle, and it has been suggested that this
should be taken into account when determining and comparing plasma
aminoglycoside concentrations.

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Indication
& Dosage

IM/IV
SERIOUS INFECTIONS CAUSED BY SENSITIVE ORGANISMS, BACTERIAL
NEONATAL SEPSIS, MENINGITIS, ENDOCARDITIS, UTI, RTI, AND GI TRACT
INFECTIONS INCLUDING PERITONITIS, SKIN, SOFT TISSUE, BONE AND JOINT
INFECTIONS, BURNS, SEPTICAEMIA BILIARY INFECTIONS, ENT INFECTIONS:

Adult: 1mg/kg 8 hrly IM. In serious life threatening infections 1.7mg/kg
6 or 8 hrly. Infants & children: Pre-mature babies and neonates
during 1st week: 2.5mg/kg 12 hrly. Neonates over 1 wee kto infants 6
months: 2.5mg/kg 8 hrly. Children 6mnths-10yrs:2-2 5mg/kg 8 hrly.
Chidren over 10yrs: 1.5mg/kg 8 hrly.
Note: Renal impairment: Increase the interval between dose keeping serum
creatinine levels as a guide. In patients on dialysis an 8 hrs reduces
serum levels of gentamicin by 50%. At the end of each session give
1-1/7mg/kg for adults and 2mg/kg for children. For IV USE, each dose of
gentamicin diluted with 50-100ml of IV fluids given over 20 mins.
Duration 7-10 days.

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Action

Active against a wide range of aerobic gram-negative and some
aGram-postive organisms including E.coil, Enterobacter, Klebsiella,
Proteus, Providentia, Pseudomonas, Campylobacter, Citrobacter, Serratia,
Staph, aureus, Staph. epidermidis and Listeria monocytogenes.

 

Interaction
Concurrent use of other nephrotoxic drugs, including other
aminoglycosides, vancomycin, some of the cephalosporins, cyclosporin,
and cisplatin, or potentially ototoxic drugs such as ethacrynic acid and
perhaps frusemide, may increase the risk of aminoglycoside toxicity. It
has been suggested that concurrent use of an antiemetic such as
dimenhydrinate may mask the early symptoms of vestibular ototoxicity.
Care is also required if other drugs with a neuromuscular blocking
action are given Comitantly.
Theneuromuscular blocking properties of aminoglycoside may be sufficient
to provoke severe respiratory depression in patients receiving general
anaesthetics or opioids.There is a theoretical possibility that the
antibacterial effects of aminoglycosides could be reduced by use with a
bacteriostatic antibacterial, but such combinations have been used
successfully in practice.
Since aminoglycosides have been shown to be incompatible with some beta
lactams in vitro these antibacterials should be administered separately
if both are required; antagonism in vivo has been reported only in a few
patients with severe renal impairment, in whom aminoglycoside activity
was diminished. Aminoglycosides exhibit synergistic activity with a
number of beta lactams in vivo.

Top  

Adverse
Effect & Precaution

Local traisent irritation.
Pregnancy: Contraindicated.
Breast Feeding: Contraindicated.
Man: May be used.

Top  

Brands
available in market

 


BIOGARACIN


Biochem


INJ


80mg/2ml


2mVIAL


7.17


INJ


20mg/2ml


2MVIAL


6.43


INJ


60mg/1.5ml


1AMP


6.46


G-MYCIN


BPL Pharma


VIAL


40mg


2ml


8.55


VIAL


40mg/ml


6ml


17.00


VIAL


40mg/ml


20ml


41.00


PAED


10mg/ml


6ml


10.00


G20/80


Kee Pharma


INJ


20mg/ml


50x5ml


180.00


INJ


80mg/ml


50x2ml


275.00


GARAMYCIN


Fulford


INJ


60mg


1.5ml


3.96


INJ


20mg


2ml


7.83


VIAL


80mg


2ml


7.40


VIAL


240mg


3ml


24.17


GENTACIN-A


Prem Pharma


INJ


60mg/1.5ml


1VIAL


0.00


GETAMICIN


Centaur


AMP


80mg/ml


2ml


5.50


AMP


20mg/0.5ml


0.5ml


3.62


GENTAMICIN-INJ


Core


INJ


80mg


2ml


8.00


GENTARIL


Alkem


VIAL


80mg


2ml


8.20


GENTASPORIN


PCI


INJ


10mg/ml


2ml


4.31


INJ


40mg/ml


2ml


7.68


INJ


40mg/ml


10ml


48.03


GENTICYN


Nichola-Piramal


INJ


40mg/ml


1.5ml


3.51


INJ


40mg/ml


2ml


7.18


INJ


20mg


2ml


5.73


GENTYRIC


Euphoric


INJ


40mg


2ml


6.95


INJ


80mg


2ml


7.77


GEROCIN


P & B labs


INJ


20mg/2ml


2mlx20


132.48


INJ


80mg/2ml


2mlx20


160.00


LYRAMCIN


Lyka


INJ


40mg/ml


2ml


6.78


INJ


10mg/ml


2ml


5.69


MERIGENTA


Mercury


INJ


20mg


2ml


6.88


INJ


60mg


1.5ml


3.68


INJ


80mg


2ml


8.27


PRIMICIN


Hindustan Antibiotics


INJ


20mg/ml


2ml


4.45


INJ


80mg/ml


2ml


6.14


REFRAGEN


Synthiko


INJ


10mg/ml


2ml


5.14


INJ


40mg/ml


2ml


8.35


TAMIACIN


Sun Pharma


INJ


80mg


2ml


6.96


ZENOTIC KIT


Plethico


INJ


40mg/ml


7.90


INJ


80mg/2ml


1PACK


8.97

 

Top 

 

   

 DrugInformation

Gentamicin

PharmacokineticsGentamicin and other aminoglycosides are poorly absorbed from thegastrointestinal tract but are rapidly absorbed after intramuscularinjection. Average peak plasma concentrations of about 4 micrograms permL have been attained in patients with normal renal function 30 to 60minutes after intramuscular administration of a dose equivalent to 1 mgof gentamicin per kg body-weight, which is similar to concentrationsachieved after intravenous infusion. There may be considerableindividual variation. Several doses are required before plasmaequilibrium concentrations occur and this may represent the saturationof binding sites in body tissues such as the kidney. Binding ofgentamicin to plasma proteins is usually low.Following parenteral administration gentamicin and other aminoglycosidesdiffuse mainly into extracellular fluids. However, there is littlediffusion into the CSF and even when the meninges are inflamed effectiveconcentrations may not be achieved; diffusion into the eye is also poor.Aminoglycosides diffuse readily into the perilymph of the inner ear.They cross the placenta but only small amounts have been reported inbreast milk.Systemic absorption of gentamicin and other aminoglycosides has beenreported after topical use on denuded skin and burns and followinginstillation into, and irrigation of, wounds, body-cavities, and joints,but not the urinary bladder.The plasma elimination half-life for gentamicin has been reported to be2 to 3 hours though it may be considerably longer in neonates andpatients with renal impairment. Gentamicin and other aminoglycosides donot appear to be metabolised and are excreted virtually unchanged in theurine by glomerular filtration. At steady-state at least 70% of a dosemay be recovered in the urine in 24 hours and urine concentrations inexcess of 100 micrograms per mL may be achieved. However, gentamicin andthe other aminoglycosides appear to accumulate in body tissues to someextent, mainly in the kidney, although the relative degree to which thisoccurs may vary with different aminoglycosides. Release from these sitesis slow and small amounts of aminoglycosides may be detected in theurine for up to 20 days or more after administration ceases. Smallamounts of gentamicin appear in the bile.The pharmacokinetics of the aminoglycosides are affected by manyfactors, which may become significant because of the relatively smalldifference between therapeutic and toxic concentrations, reinforcing theneed for monitoring. Absorption from intramuscular sites may be reducedin critically-ill patients, especially in conditions that reduceperfusion such as shock. Plasma concentrations may also be reduced inpatients with conditions which expand extracellular fluid volume orincrease renal clearance including ascites, cirrhosis, heart failure,malnutrition, spinal cord injury, burns, cystic fibrosis, and possiblyleukaemia. Clearance is also reportedly increased in intravenous drugabusers, and in patients who are febrile. In contrast, renal impairmentor reduced renal clearance for any reason (for example in neonates withimmature renal function, or in the elderly in whom glomerular functiontends to decline with age) can result in markedly increased plasmaconcentrations and/or prolonged half-lives (although in neonates initialplasma concentrations may actually be reduced, due to a larger volume ofdistribution). Plasma concentrations may also be higher than expectedfor a given dose in obese patients (in whom extracellular volume islower, relative to weight), and in patients with anaemia.Renal clearance, and hence plasma concentrations, of aminoglycosides mayvary according to a circadian cycle, and it has been suggested that thisshould be taken into account when determining and comparing plasmaaminoglycoside concentrations.

Top 

Indication& DosageIM/IVSERIOUS INFECTIONS CAUSED BY SENSITIVE ORGANISMS, BACTERIALNEONATAL SEPSIS, MENINGITIS, ENDOCARDITIS, UTI, RTI, AND GI TRACTINFECTIONS INCLUDING PERITONITIS, SKIN, SOFT TISSUE, BONE AND JOINTINFECTIONS, BURNS, SEPTICAEMIA BILIARY INFECTIONS, ENT INFECTIONS:Adult: 1mg/kg 8 hrly IM. In serious life threatening infections 1.7mg/kg6 or 8 hrly. Infants & children: Pre-mature babies and neonatesduring 1st week: 2.5mg/kg 12 hrly. Neonates over 1 wee kto infants 6months: 2.5mg/kg 8 hrly. Children 6mnths-10yrs:2-2 5mg/kg 8 hrly.Chidren over 10yrs: 1.5mg/kg 8 hrly.Note: Renal impairment: Increase the interval between dose keeping serumcreatinine levels as a guide. In patients on dialysis an 8 hrs reducesserum levels of gentamicin by 50%. At the end of each session give1-1/7mg/kg for adults and 2mg/kg for children. For IV USE, each dose ofgentamicin diluted with 50-100ml of IV fluids given over 20 mins.Duration 7-10 days.

Top    

Action

Active against a wide range of aerobic gram-negative and someaGram-postive organisms including E.coil, Enterobacter, Klebsiella,Proteus, Providentia, Pseudomonas, Campylobacter, Citrobacter, Serratia,Staph, aureus, Staph. epidermidis and Listeria monocytogenes.

 

InteractionConcurrent use of other nephrotoxic drugs, including otheraminoglycosides, vancomycin, some of the cephalosporins, cyclosporin,and cisplatin, or potentially ototoxic drugs such as ethacrynic acid andperhaps frusemide, may increase the risk of aminoglycoside toxicity. Ithas been suggested that concurrent use of an antiemetic such asdimenhydrinate may mask the early symptoms of vestibular ototoxicity.Care is also required if other drugs with a neuromuscular blockingaction are given Comitantly.Theneuromuscular blocking properties of aminoglycoside may be sufficientto provoke severe respiratory depression in patients receiving generalanaesthetics or opioids.There is a theoretical possibility that theantibacterial effects of aminoglycosides could be reduced by use with abacteriostatic antibacterial, but such combinations have been usedsuccessfully in practice.Since aminoglycosides have been shown to be incompatible with some betalactams in vitro these antibacterials should be administered separatelyif both are required; antagonism in vivo has been reported only in a fewpatients with severe renal impairment, in whom aminoglycoside activitywas diminished. Aminoglycosides exhibit synergistic activity with anumber of beta lactams in vivo.

Top  

AdverseEffect & PrecautionLocal traisent irritation.Pregnancy: Contraindicated.Breast Feeding: Contraindicated.Man: May be used.

Top  

Brandsavailable in market

 

BIOGARACIN

Biochem

INJ

80mg/2ml

2mVIAL

7.17

INJ

20mg/2ml

2MVIAL

6.43

INJ

60mg/1.5ml

1AMP

6.46

G-MYCIN

BPL Pharma

VIAL

40mg

2ml

8.55

VIAL

40mg/ml

6ml

17.00

VIAL

40mg/ml

20ml

41.00

PAED

10mg/ml

6ml

10.00

G20/80

Kee Pharma

INJ

20mg/ml

50x5ml

180.00

INJ

80mg/ml

50x2ml

275.00

GARAMYCIN

Fulford

INJ

60mg

1.5ml

3.96

INJ

20mg

2ml

7.83

VIAL

80mg

2ml

7.40

VIAL

240mg

3ml

24.17

GENTACIN-A

Prem Pharma

INJ

60mg/1.5ml

1VIAL

0.00

GETAMICIN

Centaur

AMP

80mg/ml

2ml

5.50

AMP

20mg/0.5ml

0.5ml

3.62

GENTAMICIN-INJ

Core

INJ

80mg

2ml

8.00

GENTARIL

Alkem

VIAL

80mg

2ml

8.20

GENTASPORIN

PCI

INJ

10mg/ml

2ml

4.31

INJ

40mg/ml

2ml

7.68

INJ

40mg/ml

10ml

48.03

GENTICYN

Nichola-Piramal

INJ

40mg/ml

1.5ml

3.51

INJ

40mg/ml

2ml

7.18

INJ

20mg

2ml

5.73

GENTYRIC

Euphoric

INJ

40mg

2ml

6.95

INJ

80mg

2ml

7.77

GEROCIN

P & B labs

INJ

20mg/2ml

2mlx20

132.48

INJ

80mg/2ml

2mlx20

160.00

LYRAMCIN

Lyka

INJ

40mg/ml

2ml

6.78

INJ

10mg/ml

2ml

5.69

MERIGENTA

Mercury

INJ

20mg

2ml

6.88

INJ

60mg

1.5ml

3.68

INJ

80mg

2ml

8.27

PRIMICIN

Hindustan Antibiotics

INJ

20mg/ml

2ml

4.45

INJ

80mg/ml

2ml

6.14

REFRAGEN

Synthiko

INJ

10mg/ml

2ml

5.14

INJ

40mg/ml

2ml

8.35

TAMIACIN

Sun Pharma

INJ

80mg

2ml

6.96

ZENOTIC KIT

Plethico

INJ

40mg/ml

7.90

INJ

80mg/2ml

1PACK

8.97

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