Tazobactam
Drug Name
Tazobactam is a β-lactamase inhibitor used to treat bacterial infections in patients with renal disease. It is used in combination with piperacillin, a semi-synthetic, broad-spectrum drug, under the name Zosyn. When combined with piperacillin, the spectrum of piperacillin antibacterial action is broadened. This combination can be used to treat a variety of infections, including those caused by aerobic and facultative gram-positive and gram-negative bacteria, in addition to gram-positive and gram-negative anaerobes.
Table 1. Basic profile of tazobactam.
| Description | Intravenously (IV) administered drug that restores the antibacterial activity of other antibiotic drugs |
| Target(s) | β-lactamases |
| Generic | Tazobactam |
| Commercial Name | Zerbaxa, Zosyn |
| Combination Drug(s) | Zosyn® (piperacillin & tazobactam); Zerbaxa® (ceftolozane & tazobactam) |
| Other Synonyms | Tazobactamum |
| IUPAC Name | 2S,3S,5R)-3-methyl-4,4,7-trioxo-3-(1H-1,2,3-triazol-1-ylmethyl)-4λ⁶-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid |
| Ligand Code in PDB | TAZ, TBE (bound form) |
| PDB Struture | 1VM1 (Tazobactam bound to SHV-1 β-lactamase) |
| ATC code | J01CG02 |
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Inhibitor Chemistry
Tazobactam is a member of the class of penicillanic acids that is sulbactam in which one of the exocyclic methyl hydrogens is replaced by a 1,2,3-triazol-1-yl group.
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| Figure 2. 2D structure of Tazobactam showing the group that distinguishes it from sulbactam. Figure drawn using ChemAxon. |
Drug Information
Table 2. Chemical and physical properties (DrugBank).
| Chemical Formula | C10H12N4O5S |
| Molecular Weight | 300.291 g/mol |
| Calculated Predicted Partition Coefficient (cLogP) | -1.8 |
| Calculated Predicted Aqueous Solubility (cLogS) | -1.5 |
| Solubility (in water) | 9.59 mg/mL |
| Predicted Topological Polar Surface Area (TPSA) | 122.46 Å2 |
Drug Target
Tazobactam targets β-lactamase enzymes. These bacterial enzymes hydrolyze the amide bond of the β-lactam ring in β-lactam antibiotics, rendering them unable to inhibit their target enzyme. Learn more about β-lactamases.
When used with piperacillin, tazobactam inhibits β-lactamases from degrading the drug, acting as an effective mechanism against resistance to piperacillin by bacteria. Tazobactam mimics the interactions between piperacillin and β-lactamases, thereby irreversibly inhibiting β-lactamases from degrading piperacillin.
Tazobactam is especially effective against the OHIO-1, SHV-1, and TEM groups of β-lactamases. The target of tazobactam, SHV-1, will be discussed here. SHV-1 is a broad-spectrum β-lactamase belonging to the Ambler Class A of β-lactamases. It is found in various species of bacteria, including Klebsiella spp., E. coli., and Yersinia pestis.
Drug-Target Complex
One target of tazobactam, SHV-1 β-lactamase, is an Ambler class A β-lactamase. SHV-1 β-lactamases are clinically important and are resistant to expanded-spectrum drugs including aztreonam, cephalosporins, and more.
SHV-1 cleaves the amide bond of a β-lactam drug in 2 steps: acylation and deacylation. The oxygen of the Ser70 residue in SHV-1 attacks the carbonyl atom, and causes acylation of the β-lactam ring to form an acyl intermediate. This initiates a cascade of proton transfers, ultimately resulting in the cleavage of the amide bond. Deacylation regenerates the catalytic serine residue, releasing the hydrolyzed antibiotic.
The C7 atom of open-form tazobactam (see Figure 3) forms a covalent adduct with the catalytic Ser70 (PDB ID 1vm1, Kuzin et al., 2001), mimicking the transition state of the acylation and deacylation pathway, blocking enzyme function. The amino acids Lys73 and Asn132 form hydrogen bonds with the inhibitor, which in turn form hydrogen bonds with Glu166 and Asn170. The structure also shows intact tazobactam non-covalently trapped in the crystal lattice (presumably due to excess tazobactam added to the complex).
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| Figure 3. Structure of tazobactam bound to SHV-1 β-lactamase (PDB ID 1vm1, Kuzin et al., 2001). The overall structure with a semi-transparent surface view of the enzyme is shown on the left. The inset on the right shows a ribbon representation of the active site in SHV-1. |
Pharmacologic Properties and Safety
Table 3. Pharmacokinetics: ADMET of tazobactam.
| Features | Comment(s) | Source |
|---|---|---|
| Oral Bioavailability (%) | N/A | N/A |
| IC50 | 0.14 µM (for binding to SHV-1 in S. aureus) | (Payne et al., 1994) |
| Ki (µM) | N/A | N/A |
| Half-life (hrs) | 0.7 to 1.2 hours | DrugBank |
| Duration of Action | 8 to 12 hours | FDA |
| Absorption Site | N/A | N/A |
| Transporter(s) | N/A | N/A |
| Metabolism | Tazobactam is mainly metabolized to M1, an inactive metabolite. | DrugBank |
| Excretion | ~ 80% of tazobactam is excreted unchanged in the urine. The remaining drug is excreted as a single metabolite. | DrugBank |
| AMES Test (Carcinogenic Effect) | Non AMES toxic | DrugBank |
| hERG Safety Test (Cardiac Effect) | Weak inhibitor | DrugBank |
| Liver Toxicity | Because piperacillin-tazobactam is used for serious infections, patients are often taking multiple medications including other antibiotics such as vancomycin, azithromycin, or ciprofloxacin, making the causality assessment challenging. Liver injury is usually rare but severe when it does occur. | LiverTox |
Drug Interactions and Side Effects
Table 4. Drug interactions and side effects of tazobactam.
| Features | Comment(s) | Source |
|---|---|---|
| Total Number of Drug Interactions | 51 drugs | Drugs.com |
| Major Drug Interaction(s) | bcg; cholera vaccine, live; methotrexate; typhoid vaccine, live; vancomycin | Drugs.com |
| Alcohol/Food Interaction(s) | Diets with sodium restriction for patients with heart failure, hypertension, and fluid retention. Clinical monitoring of electrolytes is recommended when administering piperacillin to these patients. | Drugs.com |
| Disease Interaction(s) | Colostridioides difficile associated diarrhea (CDAD) (major) Coagulation abnormalities (moderate) Renal dysfunction (moderate) Hemodialysis (moderate) Cystic fibrosis (moderate) Seizures (moderate) Hypokalemia, congestive heart failure, fluid retention, hypertension, hypernatremia (moderate) | Drugs.com |
| On-target Side Effects | Irritation at injection site | Drugs.com |
| Off-target Side Effects | Diarrhea, constipation, nausea, headache, sleep problems, stomach pain, confusion, muscle twitching or stiffness, seizure, low white blood cell counts, low potassium level | Drugs.com |
| CYP Interactions | CYP450 3A4 substrate | DrugBank |
Regulatory Approvals/Commercial
Tazobactam is used with piperacillin and ceftolozane to prevent these drugs from being degraded by β-lactamases. Learn more about piperacillin.
Links
Table 5. Links to learn more about tazobactam
| Comprehensive Antibiotic Resistance Database (CARD) | ARO: 0000077 |
| DrugBank | DB01606 |
| Drugs.com | https://www.drugs.com/mtm/piperacillin-and-tazobactam.html |
| FDA | https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/050684s88s89s90_050750s37s38s39lbl.pdf |
| LiverTox: National Institutes of Health (NIH) | https://www.ncbi.nlm.nih.gov/books/NBK548825/ |
| PubChem CID | 123630 |
References
Jia, B., Raphenya, A. R., Alcock, B., Waglechner, N., Guo, P., Tsang, K. K., Lago, B. A., Dave, B. M., Pereira, S., Sharma, A. N., Doshi, S., Courtot, M., Lo, R., Williams, L. E., Frye, J. G., Elsayegh, T., Sardar, D. Westman, E. L., Pawlowski, A. C., Johnson, T. A., Brinkman, F. S., Wright, G. D., McArthur, A. G. (2017) CARD 2017: expansion and model-centric curation of the Comprehensive Antibiotic Resistance Database. Nucleic Acids Research 45, D566-573. https://doi.org/10.1093/nar/gkw1004
Kuzin, A. P., Nukaga, M., Nukaga, Y., Hujer, A., Bonomo, R. A., Knox, J. R. (2001). Inhibition of the SHV-1 β-lactamase by sulfones: crystallographic observation of two reaction intermediates with tazobactam. Biochemistry, 40(6), 1861-1866. https://doi.org/10.1021/bi0022745
LiverTox - Clinical and Research Information on Drug-Induced Liver Injury. National Institutes of Health. https://www.ncbi.nlm.nih.gov/books/NBK548825/
Payne, D. J., Cramp, R., Winstanley, D. J., Knowles, D. J. (1994). Comparative activities of clavulanic acid, sulbactam, and tazobactam against clinically important beta-lactamases. Antimicrobial Agents and Chemotherapy, 38(4), 767-772. https://doi.org/10.1128/aac.38.4.767
Tazobactam. Drugs.com https://www.drugs.com/mtm/piperacillin-and-tazobactam.html
Tazobactam- DrugBank. Drugbank.ca https://go.drugbank.com/drugs/DB01606
Tazobactam - FDA https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/050684s88s89s90_050750s37s38s39lbl.pdf
Tazobactam. PubChem. https://pubchem.ncbi.nlm.nih.gov/compound/123630
Zosyn (piperacillin and tazobactam for injection). (2017) Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/050684s88s89s90_050750s37s38s39lbl.pdf
April 2025, Helen Gao, Shuchismita Dutta; Reviewed by Dr. Gregg Crichlow
https://doi.org/10.2210/rcsb_pdb/GH/AMR/drugs/OR/inh-blmase/tazobactam
