Carbenicillin

CrCl (mL/min)	Dosage
<10	Not recommended.
10-50	382-764 mg every 12-24 hours.

Should be taken on an empty stomach.

Hypersensitivity.

Restricted sodium diet. Severely impaired renal function or heart failure. Avoid contact, skin sensitisation may occur. Monitor serum potassium concentration, renal and haematological status. Spirochete infections particularly syphilis; suprainfection with penicillin-resistant organisms with prolonged use; avoid intrathecal route.

Pain at inj site and phloebitis; electrolyte disturbances; dose-dependent coagulation defect; purpura and haemorrhage; hypersensitivity reactions including uticaria; fever; joint pains; rashes; angioedema; serum sickness-like reactions; haemolytic anaemia; interstitial nephritis; neutropenia; thrombocytopenia; CNS toxicity including convulsions; diarrhoea; antibiotic-associated colitis.
Potentially Fatal: Anaphylaxis.

Probenecid prolongs T_1/2 of carbenicillin. Bacteriostatic drugs e.g. chloramphenicol, tetracyclines; other antibacterials; anticoagulants.

May interfere with diagnostic tests for urinary glucose using copper sulfate, direct Coomb's test, and test for urinary or serum proteins. May interfere with diagnostic tests that use bacteria.

Description:
Mechanism of Action: Carbenicillin has an extended spectrum of activity against gm-ve bacteria. It is used in the treatment of infections caused by P. aeruginosa and non-penicillinase-producing strains of Proteus spp. Antimicrobial activity can be enhanced by aminoglycosides. It inhibits final cross-linking stage of peptidoglycan production by binding and inactivating transpeptidases on the inner surface of the bacterial cell membrane thus inhibiting bacterial cell wall synthesis.
Pharmacokinetics:
Absorption: Not absorbed from GI tract.
Distribution: 50% bound to plasma proteins.
Excretion: half-life about 1-1.5 hr, increased in renal impairment. Excreted mainly by renal tubular secrettion and glomerular filtration.

Penicillins