Dix Uses, Dosage, Side Effects, Food Interaction and all others data.

Nalidixic acid is a synthetic narrow spectrum antibacterial. It is bacteriostatic or bactericidal depending on the concentration. Nalidixic acid appears to act by inhibiting bacterial DNA synthesis, possibly by interfering with DNA polymerization. It is rapidly and completely absorbed from the G.I. Tract. Parent drug and active metabolites are distributed to most tissues specially to the kidney and to the urine.

Nalidixic acid is a quinolone antibacterial agent for oral administration. Nalidixic acid has marked antibacterial activity against gram-negative bacteria including Enterobacter species, Escherichia coli, Morganella Morganii; Proteus Mirabilis, Proteus vulgaris, and Providencia rettgeri. Pseudomonas species are generally resistant to the drug. Nalidixic acid is bactericidal and is effective over the entire urinary pH range. Conventional chromosomal resistance to nalidixic acid taken in full dosage has been reported to emerge in approximately 2 to 14 percent of patients during treatment; however, bacterial resistance to nalidixic acid has not been shown to be transferable via R factor.

Trade Name Dix
Generic Nalidixic Acid
Nalidixic Acid Other Names Acide nalidixique, Acido nalidixico, Acidum nalidixicum, Nalidixic acid, Nalidixinsäure
Type Tablet, Syrup
Formula C12H12N2O3
Weight Average: 232.2353
Monoisotopic: 232.08479226
Protein binding

Nalidixic acid is 93% bound to protein in the blood, and the active metabolite, hydroxynalidixic acid is 63% bound.

Groups Approved, Investigational
Therapeutic Class Anti-diarrhoeal Antimicrobial drugs, Other Anti-protozoals, Systemic Urinary Anti- infective
Manufacturer Pci Pharmaceuticals
Available Country India
Last Updated: September 19, 2023 at 7:00 am


Nalidixic acid is used for -

  • Urinary tract infections caused by susceptible Gram-negative microorganisms, including the majority of Proteus strains, Klebsiella, Enterobacter spp. and E. coli.
  • Gastrointestinal infections caused by Salmonella and Shigella.

Dix is also used to associated treatment for these conditions: Urinary Tract Infection

How Dix works

Evidence exists for Nalidixic acid that its active metabolite, hydroxynalidixic acid, binds strongly, but reversibly, to DNA, interfering with synthesis of RNA and, consequently, with protein synthesis.


Dix dosage


  • Initial: Oral 1 gm every 6 hours for 7 days reducing to 500 mg every 6 hours.

Infants and children 3 month of age and over:

  • Initial: Oral 13.75 mg/kg body weight every six hours for one or two weeks.
  • Maintenance: Oral 8.25 mg/kg body weight every six hours or as prescribed by the physician.

Should be taken with food.

Side Effects

Gastro-intestinal disturbances including nausea, vomiting, diarrhoea, haemolysis in G6PD deficiency, allergic reaction including urticaria, rashes, fever, arthralgia, eosinophilia, also myalgia, muscle weakness, phototoxicity, jaundice, visual disturbances and convulsions.


ORAL (LD50): Acute: 1160 mg/kg [Rat]. 572 mg/kg [Mouse]. Toxic psychosis, convulsions, increased intracranial pressure, or metabolic acidosis may occur in patients taking more than the recommended dosage. Vomiting, nausea, and lethargy may also occur following overdosage.


General: Should be used with caution in liver disease, epilepsy or severe cerebral arteriosclerosis patients. Periodic blood counts and renal and liver function tests should be performed if treatment is continued for more than 2 weeks. If bacterial resistance emerges, rapid change of drug should be made.

Children: Should not be used to infants less than 3 months of age.


Concomitant use of Nalidixic acid with melphalan there have been reports of death froms severe blood containing diarrhoea caused by hemorrhagic ulcerative colitis. Probenecids inhibits tubular secretion of nalidixic acid and may therefore elevate serum concentration, possibly enhancing toxicity. Chlorpromazine and Perphenazine have been shown to potentiate the effect of Dix in vitro.

Food Interaction

  • Drink plenty of fluids.
  • Take with food. Food reduces irritation.

Elimination Route

Following oral administration, nalidixic acid is rapidly absorbed from the gastrointestinal tract. Bioavailability is approximately 96%. Absorption may be delayed if taken with antacids.

Half Life

1.1 to 2.5 hours in healthy adult patients, and up to 21 hours in patients with impaired renal function.

Elimination Route

Following oral administration, NegGram is rapidly absorbed from the gastrointestinal tract, partially metabolized in the liver, and rapidly excreted through the kidneys. Approximately four percent of NegGram is excreted in the feces.

Pregnancy & Breastfeeding use

Pregnancy: There is the possibility that it may cause cartilage damage and as it is a DNA-gyrase inhibitor there is a possibility of causing DNA damage too. Nalidixic acid is excreted in breast milk and there is a report of hemolytic anaemia in a breast feed child of an azotemic mother.


Dix is contraindicated to known hypersensitivity to Nalidixic acid, history of convulsive disorders and patients with porphyria. Should be used with caution in patients with liver and renal disease. Also in glucose 6 - phosphate dehydrogenase deficiency.

Special Warning

Renal Impairment: Reduced doses should be considered.

Hepatic Impairment: Reduced doses should be considered.

Acute Overdose

Symptoms: Toxic psychosis, convulsions, increased intracranial pressure, metabolic acidosis, vomiting, nausea, lethargy.

Management: Increase fluid admin; supportive measures. Anticonvulsants may be used in severe cases.

Storage Condition

Store at room temperature, up to 25° C

Innovators Monograph

You find simplified version here Dix

Dix contains Nalidixic Acid see full prescribing information from innovator Dix Monograph, Dix MSDS, Dix FDA label


What is Dix used for?

Dix is a quinolone antibiotic used to treat urinary tract infections. Dix is indicated for the treatment of urinary tract infections caused by susceptible gram-negative microorganisms, including the majority of E. Coli, Enterobacter species, Klebsiella species, and Proteus species.

How safe is Dix?

It was found that Dix was an effective and safe antimicrobial agent in acute infectious diarrhoea. It cut down the days of hospitalisation and cost. It was well tolerated even in children less than 3 months.

How does Dix work?

Dix concentrates in the renal tubules and bladder and exerts its local antibacterial actions by interference of DNA gyrase activity, thereby inhibiting DNA synthesis during bacterial replication in a dose-dependent manner.

What are the common side effects of Dix?

Common side effects of Dix are include;

  • drowsiness.
  • dizziness.
  • headache.
  • nausea.
  • vomiting.
  • diarrhea.
  • stomach cramps.

Is Dix safe during pregnancy?

Dix has been assigned to pregnancy category C by the FDA. Animal studies have revealed teratogenic and embryocidal effects and prolonged pregnancy duration. There are no controlled data in human pregnancy.

Is Dix safe during breastfeeding?

Dix should be avoided while breastfeeding a glucose-6-phosphate dehydrogenase (G6PD) deficient infant. Other agents are preferred, especially while nursing a newborn or preterm infant.

What happens if I drink alcohol while taking tablets?

Mixing alcohol with certain medications can cause nausea and vomiting, headaches, drowsiness, fainting, or loss of coordination. It also can put you at risk for internal bleeding, heart problems, and difficulties in breathing.

Can I drive after taking Dix?

Dix usually does not affect your ability to drive or operate machinery.

How often can I take Dix?

Dix is usually taken four times a day (ideally every six hours). Space your doses evenly over the day. Dix should be taken on an empty stomach.

How long does Dix stay in my system?

Peak urine levels of active drug average approximately 150 mcg to 200 mcg per mL, three to four hours after administration, with a half-life of about six hours.

Can I take Dix for a long time?

Blood counts and renal and liver function tests should be performed periodically if treatment is continued for more than two weeks.

Who should not take Dix?

You should not take Dix If you have:

  • If you are allergic to nalidixic acid; any part of nalidixic acid; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you have ever had seizures.
  • If you have porphyria.
  • If you are breast-feeding or plan to breast-feed.

What happen If I missed Dix?

Take a missed dose as soon as you think about it. If it is close to the time for your next dose, skip the missed dose and go back to your normal time. Do not take 2 doses at the same time or extra doses.

What happen if I overdose on Dix?

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Is Dix used for diarrhea?

It was found that Dix was an effective and safe antimicrobial agent in acute infectious diarrhoea. It cut down the days of hospitalisation and cost.

*** Taking medicines without doctor's advice can cause long-term problems.