nalidixic acid

Action and Spectrum

Actions and Spectrum: 

Actions: 

nalidixic acid inhibits the action of DNA gyrase, a bacterial enzyme that plays a vital role in the replication and maintenance of bacterial DNA. By blocking DNA gyrase, nalidixic acid interferes with DNA synthesis and replication, preventing bacterial cells from dividing and proliferating. 

nalidixic acid exhibits bactericidal (bacteria-killing) properties against susceptible bacteria. It effectively kills the bacteria by preventing the proper functioning of DNA gyrase, leading to DNA damage and cell death. 

Spectrum: 

nalidixic acid primarily targets gram-negative bacteria. Its spectrum of activity is narrower compared to newer quinolone antibiotics, and it is generally less effective against gram-positive bacteria. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Hypersensitivity reactions 

Rashes 

Nausea 

Vomiting 

Psychotic reactions 

Black Box Warning

Black Box Warning: 

None

Contraindication / Caution

Contraindication/Caution: 

Contraindications 

• Hypersensitivity 

Cautions 

• CNS Disorders 
• Renal impairment 
• Drug interactions 

Pregnancy / Lactation

Pregnancy consideration:  

US FDA Pregnancy category: Category C 

Breastfeeding warnings: 

Excreted in human milk in small amounts.    

Pregnancy category:  

• Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester. 
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.   
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

nalidixic acidis an antibiotic which targets a bacterial enzyme called DNA gyrase, also known as topoisomerase II. DNA gyrase is crucial for the supercoiling and relaxation of DNA during replication, transcription, and repair processes in bacteria. 

Pharmacodynamics: 

nalidixic acid primarily targets and inhibits DNA gyrase, a bacterial enzyme that plays a vital role in the supercoiling and relaxation of DNA during replication. By inhibiting this enzyme, nalidixic acid disrupts the normal functioning of DNA gyrase, preventing the bacterial DNA from unwinding and separating effectively. 

Here are the key pharmacodynamic aspects of nalidixic acid: 

The inhibition of DNA gyrase leads to the accumulation of single-strand DNA breaks during the replication process. These breaks hinder the proper progression of DNA replication, resulting in the disruption of bacterial DNA synthesis. 

Pharmacokinetics: 

Absorption  

nalidixic acid is absorbed from the gastrointestinal tract.  

Bioavailability is 96%.  

Distribution 

nalidixic acid is distributed throughout tissues and fluids in the body. 

Metabolism 

nalidixic acid undergoes limited metabolism in the liver.   

Elimination and Excretion 

The half-life is 1 to 2 hour 

nalidixic acid is excreted in the urine by the kidneys. 

Adminstartion

Administration: 

nalidixic acid is usually available as tablets or capsules. 

The tablets or capsules should be swallowed whole with a full glass of water, generally on an empty stomach. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: nalidixic acid 

Pronounced: nuh-li-DIK-sik AS-id 

Why do we use nalidixic acid? 

nalidixic acid is effective against a range of gram-negative bacteria, including Escherichia coli, Klebsiella pneumoniae, Proteus species, and Enterobacter species, which are common causes of UTIs. 

nalidixic acid interferes with DNA gyrase, an enzyme necessary for bacterial DNA replication, leading to inhibition of DNA synthesis and ultimately bacterial cell death. 

nalidixic acid may be used in patients allergic to other classes of antibiotics commonly used for UTIs, such as penicillins or sulfa drugs.