SPAMCLOX (Ampicillin & Cloxacillin)
Spamclox contains a fixed dose combinatioon of Ampicillin and Cloxacillin.
Ampicillin is amino penicillin with a broad spectrum of activity. Ampicillin is bactericidal in action. Its antibacterial spectrum includes Gram-positive organisms like Streptococci, non-betalactamase producing Staphylococci, Bacillus anthracis, Cl. tetani, C. diptheriae, Listeria monocytogenas, Enterococci and Gram-negative organisms like H.ifluenzae, N. meningitides, N. gonorrhea, M. catarrhalis, Pasteurella, Brucella, some strains of Proteus mirabilis and E.coli. Ampicillin also has activity against Salmonella and Shigella species, certain anaerobes like Leptostreptococcus species, Fusobacterium species and non-fragilis bacteriodes. Other organisms like Actinomyces, Spirochetes, Borrelia, leprospira and treponema species are sensitive to Ampicillin.
Cloxacillin is isoxazolyl penicillin and is bactericidal in action. Cloxacillin is resistant to penicillinase produced by Staphylococci. The antibacterial spectrum of Cloxacillin include penicillinase producing and non-penicillinase producing Staphylococci. It also has activity against S. pneumonia and S. pyogene.
Cloxacillin and Ampicillin may be administered in combination to produce a wider spectrum of antibacterial activity. Synergism has been demonstrated between ampicillin and cloxacillin against betalactamase producing organisms.
Ampicillin is bactericidal in low concentrations and is clinically effective not only against Gram-positive organisms susceptible to penicillin G but also to a variety of Gram-negative organisms. It is stable in the presence of gastric acid and is well-absorbed from the gastrointestinal tract. It diffuses into most body tissues and fluids; however, penetration into the cerebrospinal fluid and brain occurs only with meningeal inflammation. Ampicillin is excreted largely unchanged in the urine; its excretion can be delayed by concurrent administration of Probenecid, which inhibits the renal tubular secretion of ampicillin.
In blood serum, ampicillin is the least bound of all the penicillins; an average of about 20% of the drug is bound to plasma as compared to 60 to 90% of the other penicillins. The adminsitration of 500mg dose of ampicillin capsules results in an average peak blood serum level of approximately 3.0mcg/ml; the average peak serum level for the same dose of ampicillin suspension is approximately 3.4mcg/ml.
Cloxacillin is completely absorbed from the gastro intestinal tract after oral administration and food further reduces absorption. Cloxacillin should be taken on empty stomach, preferably 30 min before meals. After oral adminsitration, peak plasma concentrations are reached in 1-2 hours, in fasting subjects. When given as an I.M injection, peak plasma levels are reached within 30 min. doubling the dose, doubles the plasma concentration. About 90% of cloxacillin is bound to plasma proteins. The plasma half-life is about 0.5 to 1 hr. therapeutic concentrations are achieved in pleural fluid, synovial fluid and bone. In CSF when meninges are inflamed, cloxacillin crosses the placenta and is excreted in the breast milk.
Cloxacillin undergoes limited metabolism and the active drug and metabolites are excreted via kidneys by glomerular filtration and tubular secretion.
Indications and uses
SPAMCLOX is indicated for the treatment of severe bacterial infections, before infecting organism(s) is identified. It can be used for all suspected mixed Staphylococcal and Gram-negative infections. Typical situations where treatment needs to be started include pending bacteriology, acute bronchopneumonia, severe lower respiratory tract infections, wounds, post-operative infections and septicemias in patients receiving immunosuppresssive therapies. It can be prophytically used in premature babies or neonates.
Spamclox is indicated when bacterial infections are suspected or confirmed e.g. babies born of mothers with infected liquor or whose membranes ruptured more than 48 hours before delivery, babies following difficult delivery, when liquor or mucus inhalation is suspected/possible or the liquor is meconium stained. Similarly neonates requiring intubations, exchange transfusion or any surgical procedure carrying risk of infection, should be considered for prophylaxis with spamclox.
Parenteral usage of Spamclox is indicated where oral dosage is not possible or is considered inappropriate. Oral formulations should be given on empty stomach.
For adults: oral 500mg to 1 gm every 4 to 6 hours to be taken on empty stomach
A history of a previous hypersensitivity reaction to any of the penicillins is a contraindication. Spamclox is also contraindicated in infections caused by penicillinase producing organisms.
In mononucleosis infections, use of Spamclox is likely to give rise to a hypersensitivity reaction. Periodic assessment of renal, hepatic and hematological functions should be carried out during prolonged therapy. Concurrent use of Allopurinol with ampicillin increases the possibilty of skin rashes in hyperuricaemia subjects.
Animal studies have shown that spamclox has no teratogenic effects. However, as with any medications, the use of spamclox in pregnancy should be reserved for cases where its use is considered essential by physician and in his opinion the potential benefits out weighs the risk.
As with other penicillins, it may be expected that untoward reactions will be essentially limited to sensitivity phenomena. They are more likely to occur in individuals who have previously demostrated hypersensitivity to penicillin and in those with a history of allergy, asthma, hay fever or urticaria.
Spamclox in general is well tolerated. Side effects are uncommon and are of mild nature such as gastrointestinal upsets (glositis, stomatitis, nausea, vomiting, enterocolitis, pseudomembranous colitis and diarrhoea). These reactions are usually associated with oral administration of the drug.
An erythematous, midly pruritic, maculopapular skin rash has been reported fairly frequently. Other hypersensitivity reactions that have been reported are skin rash, pruritus, urticaria, erythema multiforme and an occasional case of exfoliative dermatitis. Anaphylaxis is the most serious reaction experienced and has usually associated with parenteral administration of the drug.