Ampicillin Capsule 250 (Size 2, Black/Red, marked 'UPHA/AMP 250')
Ampicillin Capsule 500 (Size 0, Scarlet/Black, marked 'UPHA/AMP 500')
Ampicillin Tablet 250 (10mm,
round, flat, scored, marked 'UP/250' white tablet)
Ampicillin Tablet 500 (Capsule
shape, scored, marked 'UP 500' white tablet)
Ampicillin Granules 125 Ampicillin Granules 250 (An almost white powder when
reconstituted forms a pink, mixed fruit flavoured homogeneous suspension.)
Ampicillin is an aminopenicillin, which has activity against
penicillin-sensitive gram-positive bacteria, as well as Escherichia coli,
Proteus mirabilis, Salmonella sp., Shigella sp., and
Haemophilus influenzae. However, many Enterobacteriaceae, H.
Influenzae, Salmonella and Shigella species are resistant
to this penicillin because of beta-lactamase production by these organisms.
It is inactive against Pseudomonas aeruginosa. Oral ampicillin can be
administered for the treatment of the following caused by susceptible
• Biliary Tract Infections
• Urinary Tract Infections
• Acute Otitis Media
• Gastro-enteritis (including
E. Coli enteritis, Salmonella enteritis and shigellosis)
• Typhoid Fever (caused by
Ampicillin is a possible alternative to erythromycin for chlamydial
infections in pregnant women. Ampicillin is also indicated as prophylaxis
for perinatal streptococcal infections and bacterial endocarditis.
MECHANISM OF ACTION
Ampicillin is bactericidal and acts by inhibiting bacterial cell wall
synthesis. Its action is dependent on its ability to reach and hind
penicillin-binding proteins (PBPs) located on the inner membrane of the
bacterial cell wall. PBPs are enzymes responsible for the assembling and
reshaping of the bacterial cell wall during growth and division. PBPs
inactivation by ampicillin results in the weakening and lysis of the
bacterial cell wall.
Ampicillin is moderately well absorbed from the GIT after oral
administration. Ampicillin is relatively acid-stable. Food can interfere
with the absorption of ampicillin so doses should preferable he taken at
least 30 minutes before meals. Peak plasma concentrations of about 26
microgram per ml have been observed 1-2 hours after a dose of 500mg.
Ampicillin is widen distributed and therapeutic concentrations can be
achieved in ascitic, pleural and joint fluids, It crosses the placenta and
small amounts are excreted in breast milk. Little ampicillin passes into the
CSF unless the meninges are inflamed. About 20% is plasma protein bound. The
plasma half-life is about 1-1.5 hours and this increases in renal failure
(7-20 hours), neonates and the elderly. Ampicillin is metabolised to some
extent to penicilloic acid which is excreted in the urine. About 20-40% of
an oral dose is excreted unchanged in the urine in 6 hours by glomerular
filtration and tubular secretion; urinary concentrations about 0.251 mg pet
ml have been reported after a dose of 500mg. High concentrations have been
reported in bile; it undergoes enterohepatic recycling and some may be
excreted in the faeces.
|Uncomplicated gonorrhoea ( gonococci-sensitive )
||Single dose of 2 or 3.5g with probenecid 1g
||25mg per kg of body weight every 6 hours
The usual adult dose is 0.25-1g
every 6 hours. The usual adult prescribing limit is up to 4g a day.
|Infants and children up to 20kg of body weight
||12.5 to 25 mg per kg of body weight every 6 hours, or 16.7 to
33.3mg per kg of body weight every 8 hours
|Children 20kg of body-weight and over
||Usual adult dose
Note : Ampicillin Paediatri
Tablet and Ampicillin Granules 125/250 is available to improve medicine
compliance in children.
There is no specific antidote In the case of overdosage, discontinue
medication, treat symptomatically and institute supportive measures as
required. Haemodialysis may aid in the removal of ampicillin from the blood.
In patients with renal function impairment, ampicillin can be removed by
haemodialysis but not by peritoneal dialysis.
reactions have been reported in patients on penicillin therapy. Serious
anaphylactic reactions require immediate emergency treatment with parenteral
epinephrine, oxygen, intravenous corticosteroids or air management
For Clostridium difficile colitis, mild cases may respond to
discontinuation of the medication alone. Moderate to severe tares may
require fluid, electrolyte, and protein replacement. In cases not responding
to tine a bow measures, oral doses of the following maybe used:
||125mg every 6 hours for 5-10 days
||250-500mg every 8 hours
||4g four times a day
If diarrhoea occurs, administration of antiperistaltic antidiarrhoeals (
eg. opioids, diphenoxylate and atropine combination, loperamide, paregoric )
is not recommended since they may delay the removal of toxins from the
colon, thereby prolonging and/ or worsening the condition.