CARBENICILLIN INDANYL SODIUM
For general information on the penicillins, including adverse effects, contraindications, overdosage, drug interactions and monitoring parameters, refer to the monograph: Penicillins, General Information.
Chemistry - An alpha-carboxypenicillin, carbenicillin is now available only as a an oral dosageform; the sodium salt of the indanyl ester of carbenicillin. It occurs as a bitter-tasting, white to off-white powder that is soluble in water and alcohol. Carbenicillin indanyl sodium may also be knownas carindacillin sodium or indanylcarbenicillin sodium.
Uses, Indications - As there are no veterinary-approved carbenicillin products, all uses of this drugare considered extra-label. Generally, carbenicillin is used parenterally in the treatment of systemic
Pseudomonas aeruginosa infections in small animals, usually in combination with an appropriateaminoglycoside agent. Synergy may occur against some Pseudomonas strains when used incombination with aminoglycosides, but in vitro inactivation of the aminoglycoside may also occur(see Drug Interactions below) if the drugs are physically mixed together or in patients with severerenal failure.
Because the oral form is poorly absorbed and the drug has a rapid elimination half-life, oraltherapy is only indicated for the treatment of susceptible urinary tract (and possibly prostate) infections as levels are too low in serum and other tissues for adequate therapy in other systemic
Pseudomonas infections.
Pharmacokinetics (specific) - The oral form (indanyl sodium) of the drug is rapidly, but incompletely, absorbed (see above) with only 30-40% of an oral dose absorbed in humans. Peaklevels of the indanyl sodium are attained in humans about 30 minutes after administration, but israpidly hydrolyzed into the base.
Attainable serum levels after oral therapy are generally too low to treat systemic infections, buthigh levels are achieved in the urine. The volume of distribution is reportedly 0.18-0.2 L/kg in dogsand cats and 0.29-0.4 L/kg in the horse. The drug is 29-60% bound to serum proteins (human).
Carbenicillin is thought to cross the placenta and is found in small quantities in milk. In cattle, mastitic milk levels of carbenicillin are approximately twice those found in normal milk, but are toolow to treat most causal organisms.
Carbenicillin is eliminated primarily by the kidneys, via both tubular secretion and glomerularfiltration. Concurrent probenecid administration can slow elimination and increase blood levels. Inhumans, about 2-5% of the drug is metabolized by hydrolysis to inactive compounds. The half-lifein dogs and cats is reportedly 45-75 minutes and 60-90 minutes in the horse. Clearance is 1.8ml/kg/min in the dog and 4.6 ml/kg/min in the horse.
Chemistry - An alpha-carboxypenicillin, carbenicillin is now available only as a an oral dosageform; the sodium salt of the indanyl ester of carbenicillin. It occurs as a bitter-tasting, white to off-white powder that is soluble in water and alcohol. Carbenicillin indanyl sodium may also be knownas carindacillin sodium or indanylcarbenicillin sodium.
Storage, Stability, Compatibility
The oral indanyl sodium tablets should be stored in tightcontainers and protected from temperatures greater than 30°C. The sodium injection powder forreconstitution should be stored at temperatures less than 30°C.Pharmacology - CARBENICILLIN INDANYL SODIUM
The alpha-carboxypenicillins, sometimes called anti-pseudomonal penicillins, include both carbenicillin and ticarcillin. These agents have similar spectrums of activity as theaminopenicillins (ampicillin, etc.) including increased activity against many strains of gram negativeaerobes not covered by either the natural penicillins or penicillinase-resistant penicillins, includingsome strains of E. coli, Klebsiella, and Haemophilus. Additionally, they have activity against severalgram negative organisms of the family Enterobacteriaceae, including many strains of Pseudomonasaeruginosa and Acinetobacter. Like the natural penicillins they are susceptible to inactivation bybeta-lactamase-producing bacteria (e.g., Staph aureus). Although not as active as the naturalpenicillins, they do have some activity against many anaerobic bacteria including Clostridialorganisms.Uses, Indications - As there are no veterinary-approved carbenicillin products, all uses of this drugare considered extra-label. Generally, carbenicillin is used parenterally in the treatment of systemic
Pseudomonas aeruginosa infections in small animals, usually in combination with an appropriateaminoglycoside agent. Synergy may occur against some Pseudomonas strains when used incombination with aminoglycosides, but in vitro inactivation of the aminoglycoside may also occur(see Drug Interactions below) if the drugs are physically mixed together or in patients with severerenal failure.
Because the oral form is poorly absorbed and the drug has a rapid elimination half-life, oraltherapy is only indicated for the treatment of susceptible urinary tract (and possibly prostate) infections as levels are too low in serum and other tissues for adequate therapy in other systemic
Pseudomonas infections.
Pharmacokinetics (specific) - The oral form (indanyl sodium) of the drug is rapidly, but incompletely, absorbed (see above) with only 30-40% of an oral dose absorbed in humans. Peaklevels of the indanyl sodium are attained in humans about 30 minutes after administration, but israpidly hydrolyzed into the base.
Attainable serum levels after oral therapy are generally too low to treat systemic infections, buthigh levels are achieved in the urine. The volume of distribution is reportedly 0.18-0.2 L/kg in dogsand cats and 0.29-0.4 L/kg in the horse. The drug is 29-60% bound to serum proteins (human).
Carbenicillin is thought to cross the placenta and is found in small quantities in milk. In cattle, mastitic milk levels of carbenicillin are approximately twice those found in normal milk, but are toolow to treat most causal organisms.
Carbenicillin is eliminated primarily by the kidneys, via both tubular secretion and glomerularfiltration. Concurrent probenecid administration can slow elimination and increase blood levels. Inhumans, about 2-5% of the drug is metabolized by hydrolysis to inactive compounds. The half-lifein dogs and cats is reportedly 45-75 minutes and 60-90 minutes in the horse. Clearance is 1.8ml/kg/min in the dog and 4.6 ml/kg/min in the horse.