Unasyn Oral
Generic Name
Sultamicillin (sulbactam & ampicillin)................375 mg
Powder for Suspension (per 5 ml)
Sultamicillin...................................................250 mg
Broad spectrum antibacterial agent
Following oral administration in humans, sultamicillin is hydrolysed during absorption to provide sulbactam and ampicillin in a 1:1 molar ratio in the systemic circulation. The bioavilability of an oral dose is 80% of an equal intravenous dose of sulbactam and ampicillin. Administration following food does not affect the systemic bioavailability of sultamicillin. Peak serum levels of ampicillin following sultamicillin are approximately twice those of an equal dose oral ampicillin. Elimination half-lives are approximately 0.75 and 1 hour for sulbactam and ampicillin respectively in healthy volunteers, with 50-75% of each agent being excreted in the urine unchanged. Elimination half-lives are increased in the elderly and in patients with renal dysfunction. Probenecid decreases the renal tubular secretion of both ampicillin and sulbactam. Concurrent use of probenecid with sultamicillin results in increased and prolonged blood levels of ampicillin and sulbactam.
Biochemical studies with cell-free bacterial systems have shown sulbactam to be an irreversible inhibitor of most important beta-lactamases that occur in penicillin-resistant organisms. It possesses significant anitbacterial acitivity only against Neisseriaceae, Acinetobacter calcoaceticus, Bacteriodes sp., Branhamella catarrhalis and Pseudomonas cepacia. The potential for sulbactam sodium's preventing the destruction of penicillins and cephalosporins by resistant organisms was confirmed in whole organism studies using resistant strains, in which sulbactm sodium exhibited marked studies using resistant strains, in which sulbactam sodium exhibited marked synergestic effects with penicillins and cephalosporins. Since sulbactam also binds to some penicillin-binding proteins some sensitive strains are rendered more susceptible to the combination than to the beta-lactam antibiotic alone.
The bactericidal component of this product is ampicillin which, like benzyl penicillin, acts against sensitive organisms during the stage of active multiplication by the inhibition of biosynthesis of cell wall mucopeptide.
Unaysn Oral is effective against a wide range of gram-positive and gram-negative bacteria including: Staphylococcus aureus and epidermidis (including penicillin-resistant and some methicillin-resistant strains); Streptococcus pneumoniae, Streptococcus faecalis and other Streptococcus species; Haemophilus influenzae and parainfluenzae (both beta-lactamase positive and negative strains); Branhamella catarrhalis; anaerobes including Bacteriodes fragilis and related species; Escherichia coli; Klebsiella species; Proteus species (both indole-positive and indole-negative); Enterobacter species; Morganella morganii; Citrobacter species; Neisseria meningitidis and Neisseria gonorrhoeae.
Unasyn Oral is indicated for infections caused by susceptible microorganisms. Typical indications are:
  1. Upper respiratory tract infections: Sinusitis, otitis media, and tonsilitis.
  2. Lower respiratory tract infections: Bacterial pneumonias and bronchtis.
  3. Urinary tract infections and pyelonephritis
  4. Skin and soft tissue infections
  5. Gonococcal infections

Unasyn Oral may also be indicated in patients requiring sulbactam/ampicillin therpay following initial treatment with Unasyn IM/IV.

The use of this product is contraindicated in individuals with a history of an allergic reaction to any of the penicillins.
Drug Interactions
Concurrent administration of allopurinol and ampicillin increases substantially the incidence of rashes in patients receiving both drugs as compared to patients receiving ampicillin alone. There are no data concerning concurrent adminsitration of allopurinol and sultamicillin.
Side Effects/Adverse Effects
Sultamicillin is generally well tolerated. The majority of side effects observed were of mild to moderate severity and were normally tolerated with continued treatment.
  • Gastrointestinal: The most frequently observed side effect was diarrhea/loose stool. Nausea, vomiting, epigastric distress, and abdominal pain/cramps have been observed. As with other ampicillin-class antibiotics, enterocolitis and pseudomemranous colitis rarely occur.
  • Skin/Skin Structure: Rash and itching were infrequently observed.
  • Miscellaneous: Drowsiness/sedation, fatigue/malaise and headache have been rarely observed.
Since infectious mononucleosis is viral in origin, ampicillin should not be used in treatment. A high percentage of patients with mononucleosis who receive ampicillin develop a skin rash.
It is expected that the adverse reactions associated with use of ampicillin will be occasionally observed.
Pregnancy & Lactation
Animal reproduction studies have revealed no evidence of impaired fertility or harm to the fetus due to sultamicillin. However, safety for use in human pregnancy has not been established.
Low concentrations of ampicillin and sulbactam are excreted in the milk; therefore; therefore, caution should be exercised when sultamicillin is administered to a nursing woman.
Dosage & Administration
1. The recommended dose of sultamicillin in adults (including elderly patients):
  • 375-750 mg twice daily.
2. The dosage for most infections in children weighing less than 30 kg:
  • 25-50 mg/kg/day in 2 divded doses depending on the severity of the infection and the physician's judgement.
  • For children weighing 30 kg or more, the usual adult dose should be given.
In both adults and children, treatment is usually continued until 48 hours after pyrexia and other abnormal signs have resolved. Treatment is normally given for 5-14 days, but the treatment period may be extended if necessary.

3. In the treament of uncomplicated gonorrhoea, sultamicillin can be given as a single oral dose of:
  • 2.25 g (six 375 mg tablets).
  • Concomitant probenecid 1.0 g should be administered in order to prolong plasma concentrations of sulbactam and ampicillin.
  • Cases of gonorrhoea with a suspected lesion of syphilis should have dark field examinations before receiving sultamicillin and monthly serological tests for a minimum of four months.
It is recommended that there be at least 10 days treatment for any infection caused by hemolytic streptococci to prevent the occurrence of acute rheumatic fever or glomerulonephritis.
In patients with severe impairment of renal function (creatinine clearance 30 ml/min), the elimination kinetics of sulbactam and ampicillin are similarly affected and hence the plasma ratio of one to the other will remain consistant. The dose of sultamicillin in such patients should be administered less frequently in accordance with usual practice for ampicillin.
The reconstituted oral suspension must be stored under refrigeration and discarded after 14 days.
Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy. These reactions are more apt to occur in inidividuals with a history of penicillin hypersensitivity and/or hypersensitivity reactions to multiple allergens. There have been reports if individuals with a history of penicillin hypersensitivity who have experienced severe reactions when treated with cephalosporins. Before therapy with a penicillin, careful inquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins, and other allergens. If an allergic reaction occurs, the drug should be discontinued and the appropriate therapy instituted.
Serious anapyhlactic reactions require immediate emergency treatment with adrenaline. Oxygen, intravenous steroids, and airway management, including intubation, should be administered as indicated.
As with any antibiotic preparation, constant observation for signs of overgrowth of nonsuceptible organisms, including fungi, is essential. Should superinfection occur, the drug should be discontinued and/or appropriate therapy institued.
It is advisable to check periodically for organ sysmte dysfunction during prolonged therapy; this includes renal, hepatic and hematopoietic systems.
Use in Children
The principal route of excretion of sulbactam and ampicillin following oral administration of sultamicillin is via the urine. Because renal function is not fully developed in neonates, this should be considered when using sultamicillin in neonates.
Store at room temperature.
Reconstituted oral suspension must be stored under refrigeration and discarded after 14 days.
Unasyn Oral (sultamicillin) tablets 375 mg. Pack of 12 tablets.
Bottles containing powder for oral suspension 3 g/bottle. On constitution, each 5 ml (one teaspoonful) contains 250 mg Unasyn (sultamicillin).
Date Added/Updated
22nd April 2014 1:11 pm


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