Definition
Ticarcillin is a semisynthetic, broad‑spectrum β‑lactam antibiotic belonging to the carboxypenicillin subclass of penicillins. It exerts its antibacterial effect by inhibiting bacterial cell‑wall synthesis.
Overview
Ticarcillin is administered parenterally (intravenously or intramuscularly) for the treatment of severe infections caused by susceptible Gram‑negative and some Gram‑positive bacteria, including Pseudomonas aeruginosa, Enterobacter spp., Klebsiella spp., and Escherichia coli. Because many organisms produce β‑lactamases that can inactivate ticarcillin, it is commonly formulated with the β‑lactamase inhibitor clavulanic acid (ticarcillin‑clavulanate) to extend its antibacterial spectrum.
The drug is eliminated primarily unchanged in the urine; renal function therefore influences dosing. Adverse effects are similar to those of other penicillins and include hypersensitivity reactions, gastrointestinal disturbances, and, less frequently, hematologic abnormalities. Cross‑reactivity with other β‑lactam antibiotics may occur in patients with penicillin allergy.
Etymology / Origin
The name “ticarcillin” combines the prefix “ti‑,” referring to the thienyl (a sulfur‑containing heterocycle) side chain present in the molecule, with “carb,” indicating its derivation from the carboxypenicillin series of penicillins, and the standard suffix “‑cillin” used for penicillin antibiotics. The compound was first synthesized in the early 1970s and introduced into clinical practice shortly thereafter.
Characteristics
| Property | Details |
|---|---|
| Chemical class | Carboxypenicillin (a penicillin derivative) |
| Molecular formula | C₁₈H₁₉N₃O₅S₂ |
| Mechanism of action | Binds to penicillin‑binding proteins, inhibiting transpeptidation during peptidoglycan synthesis, leading to cell‑wall rupture and bacterial death. |
| Spectrum of activity | Primarily Gram‑negative bacilli; limited activity against Gram‑positive cocci. Enhanced against β‑lactamase‑producing strains when combined with clavulanic acid. |
| Pharmacokinetics | Rapid intravenous distribution; low protein binding; renal excretion unchanged; half‑life ≈ 0.8–1.2 h in normal renal function. |
| Formulations | Available as sodium salt for injection; commonly combined with clavulanic acid (ticarcillin‑clavulanate, ratio 4:1). |
| Resistance concerns | Hydrolysis by extended‑spectrum β‑lactamases; efflux pumps; altered penicillin‑binding proteins. |
| Regulatory status | Approved in many countries for inpatient use; not typically available as an oral formulation. |
Related Topics
- Penicillins – the broader class of β‑lactam antibiotics from which ticarcillin is derived.
- Carboxypenicillins – a subgroup including carbenicillin and temocillin, characterized by a carboxylic acid side chain.
- Ticarcillin‑clavulanate – a fixed‑dose combination that pairs ticarcillin with the β‑lactamase inhibitor clavulanic acid.
- β‑lactamase inhibitors – compounds such as clavulanic acid, sulbactam, and tazobactam that protect β‑lactam antibiotics from enzymatic degradation.
- Bacterial resistance mechanisms – especially production of extended‑spectrum β‑lactamases (ESBLs) and carbapenemases that limit the utility of carboxypenicillins.
- Other broad‑spectrum β‑lactams – including piperacillin, cefepime, and carbapenems, which are alternatives for treating multidrug‑resistant Gram‑negative infections.