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Carbenicillin Indanyl Sodium

Class: Extended-spectrum Penicillins
Chemical Name: [2S-(2α,5α,6β)]-6-[[3-[(2,3-dihydro-1H-inden-5-yl)oxy]-1,3-dioxo-2-phenylpropyl]-amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.O]heptane-2-carboxylic acid monosodium salt
CAS Number: 26605-69-6
Brands: Geocillin


Antibacterial; β-lactam antibiotic; α-carboxypenicillin classified as an extended-spectrum penicillin.1 3 6

Uses for Carbenicillin Indanyl Sodium

Urinary Tract Infections (UTIs)

Treatment of acute or chronic infections of the upper and lower urinary tract or for asymptomatic bacteriuria caused by susceptible enterococci, Enterobacter, Escherichia coli, Morganella morganii, Proteus mirabilis, P. vulgaris, Providencia rettgeri, Pseudomonas, or enterococci.1 2 4 12 27 28 29 30 33

Not a drug of choice for these UTIs.2 4 33 Because only low carbenicillin concentrations are attained in urine and renal parenchyma in patients with severe renal impairment, the drug may be ineffective for treatment of UTIs in patients with Clcr <10 mL/minute.11


Treatment of acute or chronic prostatitis caused by susceptible Enterobacter, E. coli, P. mirabilis, or enterococci.1 23 24

Perioperative Prophylaxis

Has been used for perioperative prophylaxis in patients undergoing transrectal biopsy of the prostate; 31 not a drug of choice for such prophylaxis.36 37

Carbenicillin Indanyl Sodium Dosage and Administration


Oral Administration

Administer orally.1


Available as carbenicillin indanyl sodium; dosage expressed in terms of carbenicillin.1


Urinary Tract Infections (UTIs)
UTIs Caused by Enterobacter, E. coli, or Proteus

382–764 mg 4 times daily.1 12 26 27 28 Usual duration is ≥10 days;12 29 prolonged therapy may be required for chronic UTIs.28

UTIs Caused by Pseudomonas or Enterococcus

764 mg 4 times daily.1 Usual duration is ≥10 days;12 29 prolonged therapy may be required for chronic UTIs.28


764 mg 4 times daily.1 23 24 Usual duration is ≥2–4 weeks.23 24

Special Populations

Renal Impairment

Dosage may need to be decreased in patients with Clcr 10–20 mL/minute.1 Should not be used in those with Clcr <10 mL/minute.1

Geriatric Patients

No dosage adjustments except those related to renal impairment. (See Renal Impairment under Dosage and Administration.)

Cautions for Carbenicillin Indanyl Sodium


  • Known hypersensitivity to any penicillin.1




Possible emergence and overgrowth of nonsusceptible bacteria or fungi.1 Discontinue and institute appropriate therapy if superinfection occurs.1

Sensitivity Reactions

Hypersensitivity Reactions

Serious and occasionally fatal hypersensitivity reactions (including anaphylaxis) reported with penicillins.1 Anaphylaxis occurs most frequently with parenteral penicillins but has occurred with oral penicillins.1

Prior to initiation of therapy, make careful inquiry regarding previous hypersensitivity reactions to penicillins, cephalosporins, or other drugs.1 Partial cross-allergenicity occurs among penicillins and other β-lactam antibiotics including cephalosporins and cephamycins.1 19 20 21 22

If hypersensitivity reaction occurs, discontinue immediately and institute appropriate therapy as indicated (e.g., epinephrine, corticosteroids, maintenance of an adequate airway and oxygen).1

General Precautions

Laboratory Monitoring

Periodically assess organ system functions, including renal, hepatic, and hematopoietic, during prolonged therapy.1

Selection and Use of Anti-infectives

To reduce development of drug-resistant bacteria and maintain effectiveness of carbenicillin and other antibacterials, use only for treatment or prevention of infections proven or strongly suspected to be caused by susceptible bacteria.a

When selecting or modifying anti-infective therapy, use results of culture and in vitro susceptibility testing.a In the absence of such data, consider local epidemiology and susceptibility patterns when selecting anti-infectives for empiric therapy.a

Coombs’ Test Results

Positive direct Coombs’ test results reported with carbenicillin.b This may interfere with certain hematologic studies or transfusion cross-matching procedures.b

Sodium Content

Each tablet of carbenicillin indanyl sodium containing 382 mg of carbenicillin contains 23 mg of sodium.1

Specific Populations


Category B.1


Distributed into milk.1 Use with caution.1

Pediatric Use

Safety and efficacy not established in pediatric patients.1

A high incidence of nausea, vomiting, and diarrhea reported when the drug was used in children.25

Hepatic Impairment

Serum concentrations of extended-spectrum penicillins may be increased and half-life prolonged in patients with hepatic impairment.b

Renal Impairment

Dosage adjustment may be necessary in patients with Clcr 10–20 mL/minute to prevent accumulation of the drug.1

Should not be used in patients with severe renal impairment (i.e., Clcr <10 mL/minute) since these patients will not achieve therapeutic concentrations in urine.1

Common Adverse Effects

GI effects,1 7 including dose-related13 nausea,1 2 12 13 15 vomiting,1 12 13 15 diarrhea,1 12 13 15 abdominal cramps,1 12 and flatulence.1 12 Unpleasant aftertaste and smell.2 12 15

Interactions for Carbenicillin Indanyl Sodium

Specific Drugs and Laboratory Tests

Drug or Test




Some in vitro evidence of additive or synergistic antibacterial effects with extended-spectrum penicillins against some Enterobacteriaceae or Pseudomonas aeruginosa;b synergism is unpredictable and antagonism has been reported rarelyb

β-lactam anti-infectives

Some in vitro evidence of additive or partially synergistic antibacterial effects with other β-lactam antibiotics (e.g., cephalosporins, cephamycins);b synergism is unpredictable and indifference or antagonism has been reported more frequently than synergismb


Possible decreased renal clearance of methotrexate and increased risk of methotrexate adverse effectsb

Patients receiving penicillins and methotrexate concomitantly should be monitored carefullyb


Decreased renal tubular secretion of carbenicillin and increased and prolonged carbenicillin plasma concentrations1 b

Tests for glucose

Possible false-positive reactions in urine glucose tests using Clinitest, Benedict’s solution, or Fehling’s solutionb

Use glucose tests based on enzymatic glucose oxidase reactions (e.g., Clinistix, Tes-Tape)b

Tests for uric acid

Possible falsely increased serum uric acid concentrations when the copper-chelate method is used;b phosphotungstate and uricase methods for serum uric acid appear to be unaffectedb

Carbenicillin Indanyl Sodium Pharmacokinetics



Carbenicillin indanyl sodium is rapidly, but incompletely, absorbed following oral administration.1 2 4 5 13 Approximately 30–40% of an oral dose absorbed from GI tract.5 9 10 14

After absorption, carbenicillin indanyl sodium is rapidly and completely hydrolyzed to carbenicillin and indanol.2 5 8 13 Peak serum concentrations of carbenicillin generally attained within 0.5–2 hours.1 12 14 15


Plasma Protein Binding




Following absorption from GI tract, carbenicillin indanyl sodium is rapidly hydrolyzed by plasma and tissue esterases to carbenicillin and indanol.2 8 13 18

Elimination Route

Indanol is rapidly excreted in urine as glucuronide and sulfate conjugates;2 13 carbenicillin and its metabolites are excreted principally in urine.1 2 16


0.78–1 hour.b

Special Populations

Serum concentrations of extended-spectrum penicillins may be increased and half-life prolonged in patients with hepatic impairment.b In patients with both renal and hepatic impairment, serum half-life of carbenicillin may range up to 32 hours.b

Serum half-life ranges from 9.4–23.4 hours in patients with Clcr <10 mL/minute per 1.73 m2.b





≤30°C in tight container;38 39 protect from moisture.39

Actions and Spectrum

  • Based on spectrum of activity, classified as an extended-spectrum penicillin.3 6 More active against gram-negative bacilli than natural penicillins, penicillinase-resistant penicillins, and aminopenicillins.b

  • Available as the sodium salt of the indanyl ester of carbenicillin.1 8 Carbenicillin indanyl sodium is rapidly hydrolyzed to carbenicillin in vivo;1 2 3 5 6 8 13 18 the antibacterial activity of the ester is not clinically important.2 6 18

  • Usually bactericidal.b

  • Like other β-lactam antibiotics, antibacterial activity results from inhibition of bacterial cell wall synthesis.1 b

  • Spectrum of activity includes some gram-positive aerobes and many gram-negative aerobes.1 b Inactive against mycobacteria, Mycoplasma, Rickettsia, fungi, and viruses.b

  • Gram-positive aerobes: active in vitro against enterococci (e.g., Enterococcus faecalis), Staphylococcus (non-penicillinase-producing strains), and Streptococcus.1 b

  • Gram-negative aerobes: active in vitro against Enterobacter, Escherichia coli, Proteus mirabilis, P. vulgaris, Morganella morganii, Providencia rettgeri, and Pseudomonas.1 b Klebsiella usually are resistant;1 b resistance has been reported in Pseudomonas.1 b

  • Complete cross-resistance generally occurs between carbenicillin and ticarcillin.b

Advice to Patients

  • Advise patients that antibacterials (including carbenicillin) should only be used to treat bacterial infections and not used to treat viral infections (e.g., the common cold).a

  • Importance of completing full course of therapy, even if feeling better after a few days.a

  • Advise patients that skipping doses or not completing the full course of therapy may decrease effectiveness and increase the likelihood that bacteria will develop resistance and will not be treatable with carbenicillin or other antibacterials in the future.a

  • Importance of discontinuing therapy and informing clinician if an allergic reaction occurs.a

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.1

  • Importance of women informing clinician if they are or plan to become pregnant or plan to breast-feed.1

  • Importance of informing patients of other important precautionary information. (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Carbenicillin Indanyl Sodium


Dosage Forms


Brand Names



Tablets, film-coated

382 mg (of carbenicillin)



AHFS DI Essentials. © Copyright 2017, Selected Revisions May 1, 2004. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.


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a. Pfizer. Geocillin (carbenicillin indanyl sodium) tablets prescribing information. New York, NY; 2003 Sept.

b. AHFS Drug Information 2004. McEvoy GK, ed. Extended-spectrum Penicillins General Statement. American Society of Health-System Pharmacists; 2004:341-9.