Ticarcillin

Ticarcillin is a broad-spectrum beta-lactam antibiotic of the carboxypenicillin subclass of penicillins. It inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, producing a bactericidal effect.

Spectrum and combinations: It has activity mainly against gram-negative aerobes including Escherichia coli, Klebsiella, Proteus, Haemophilus influenzae, and some Pseudomonas aeruginosa. It is less active against gram-positive cocci and remains susceptible to beta-lactamases. When paired with clavulanic acid (ticarcillin/clavulanate, such as Timentin), its coverage expands to beta-lactamase–producing strains and many anaerobes, including Bacteroides fragilis.

Clinical use: Ticarcillin (often in combination) has been used for serious infections caused by susceptible organisms, including intra-abdominal, gynecologic, septicemia, and lower respiratory tract infections. Its use has declined with the availability of newer agents and alternative beta-lactamase–stable combinations.

Pharmacology: Administered intravenously or intramuscularly; excreted primarily by the kidneys with a short half-life, necessitating renal dosing adjustments. The disodium salt adds a sodium load, which can affect fluid balance in susceptible patients.

Adverse effects: Hypersensitivity, rash, diarrhea, and superinfections are possible; high-dose therapy or renal impairment can be associated with neurotoxicity or seizures. Cross-reactivity with other penicillins may occur. Caution is advised when combining with aminoglycosides or certain IV solutions due to compatibility and stability considerations.

Resistance and status: Resistance mainly arises from beta-lactamases and altered PBPs. Because of safety concerns and competition from newer agents, ticarcillin is rarely a first-line choice today, with piperacillin-tazobactam and others often preferred.