Quintor500 mg

Quintor 500 mg is a broad-spectrum fluoroquinolone antibiotic indicated for the treatment of single infections or mixed infections caused by two or more susceptible organisms. It is also effective against bacteria that are resistant to other antibiotic classes, including aminoglycosides, penicillins, and cephalosporins.

Because therapeutic antibacterial concentrations are achieved in serum, body tissues, and urine following oral administration, Quintor 500 mg can be used alone (pending sensitivity results) or in combination with an aminoglycoside, a beta-lactam antibiotic, or an antibiotic active against anaerobes — particularly when severe neutropenia is present or when Bacteroides fragilis infection is suspected.

Quintor 500 mg is indicated for the following infections caused by susceptible bacteria:

Severe Systemic Infections

Septicemia, bacteremia, peritonitis, infections in immunosuppressed patients with hematological or solid tumors, and serious infections in intensive care patients including infected burns.

Respiratory Tract Infections

Lobar and bronchopneumonia, acute and chronic bronchitis, acute exacerbations of cystic fibrosis, bronchiectasis, and empyema.

Urinary Tract Infections (UTIs)

Uncomplicated and complicated urethritis, cystitis, pyelonephritis, prostatitis, and epididymitis.

Skin and Soft Tissue Infections

Infected ulcers, wound infections, abscesses, cellulitis, otitis externa, erysipelas, and infected burns.

Gastrointestinal Infections

Enteric fever (typhoid), infective diarrhea, and other susceptible gastrointestinal tract infections.

Biliary Tract Infections

Cholangitis, cholecystitis, and empyema of the gallbladder.

Intra-abdominal Infections

Peritonitis and intra-abdominal abscesses.

Bone and Joint Infections

Osteomyelitis and septic arthritis caused by susceptible organisms.

Pelvic Infections

Salpingitis, endometritis, and pelvic inflammatory disease (PID).

Eye, Ear, Nose, and Throat (EENT) Infections

Otitis media, sinusitis, mastoiditis, and tonsillitis.

Gonorrhea

Including urethral, rectal, and pharyngeal gonorrhea caused by beta-lactamase-producing organisms or organisms moderately sensitive to penicillin.

4-Quinolone Preparations / Anti-diarrhoeal Antimicrobial Drugs

Quintor 500 mg is a synthetic fluoroquinolone antibacterial agent with a broad spectrum of activity against Gram-negative and Gram-positive aerobic bacteria.

Spectrum of Activity

Quintor 500 mg is active against most Gram-negative aerobic bacteria including Enterobacteriaceae and Pseudomonas aeruginosa, making it one of the few oral agents with reliable antipseudomonal activity. It is also active against Gram-positive aerobic bacteria including penicillinase-producing, non-penicillinase-producing, and methicillin-resistant staphylococci. However, many strains of streptococci show relative resistance and should be treated with caution.

Mechanism of Action

Quintor 500 mg exerts its bactericidal effect by inhibiting bacterial DNA gyrase (topoisomerase II), an enzyme essential for bacterial DNA replication, transcription, repair, and recombination. By blocking this enzyme, Quintor 500 mg prevents bacterial DNA from being properly copied, halting reproduction and causing cell death.

Pharmacokinetics

• Absorption: Rapidly and well absorbed from the gastrointestinal tract following oral administration.
• Distribution: Widely distributed into body tissues and fluids including the lungs, prostate, bone, and bile — achieving high tissue concentrations relative to plasma levels.
• Half-life: Approximately 3.5 hours, supporting twice-daily dosing for most indications.
• Elimination: 30–50% of an oral dose is excreted in the urine within 24 hours as unchanged drug and biologically active metabolites.

Oral Tablets

• Quintor 500 mg tablets may be taken with or without food.
• Patients should drink plenty of fluids throughout treatment to maintain adequate hydration and reduce the risk of crystalluria.
• Avoid taking Quintor 500 mg simultaneously with milk, yogurt, or calcium-enriched beverages, as these may significantly reduce absorption.
• Antacids, iron supplements, zinc, and calcium-containing products should be taken at least 2 hours after or 6 hours before Quintor 500 mg.

IV Infusion — Step-by-Step Administration Guide

1. Check the infusion bag for minute leaks by firmly squeezing it. Discard if any leaks are found or if the seal is not intact.
2. Do not use if the solution appears cloudy or contains visible particles or a precipitate.
3. Do not use flexible infusion bags in series connections.
4. Close the flow control clamp on the administration set.
5. Remove the cover from the port at the bottom of the bag.
6. Insert the piercing pin of the administration set into the port with a twisting motion until firmly seated.
7. Suspend the bag from the IV hanger.
8. Squeeze and release the drip chamber to establish the proper fluid level during infusion.
9. Open the flow control clamp to expel air from the set, then close it.
10. Regulate the rate of administration using the flow control clamp.

The following interactions require careful attention when administering Quintor 500 mg:

Antacids, Sucralfate, and Mineral Supplements

Concurrent use with magnesium- or aluminum-containing antacids, sucralfate, or products containing calcium, iron, or zinc significantly reduces Quintor 500 mg absorption. These products should be taken at least 2 hours after or 6 hours before Quintor 500 mg.

Dairy Products

Quintor 500 mg should not be taken with milk or yogurt alone, as these can substantially reduce drug absorption. However, dietary calcium consumed as part of a regular balanced meal does not significantly affect Quintor 500 mg absorption.

Theophylline

Concurrent use may increase theophylline plasma concentrations, raising the risk of theophylline-related adverse effects such as seizures and palpitations. Close monitoring of theophylline levels is recommended.

Warfarin and Anticoagulants

Quintor 500 mg may potentiate the anticoagulant effect of warfarin. INR should be monitored closely in patients on concurrent anticoagulant therapy.

NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)

Concomitant use with NSAIDs may increase the risk of CNS stimulation and convulsions. Use with caution in patients already predisposed to seizures.

Antidiabetic Drugs

Co-administration with antidiabetic agents (such as glibenclamide) may increase the risk of hypoglycemia. Blood glucose levels should be monitored during concurrent use.

Quintor 500 mg is generally well tolerated. The following adverse effects have been reported:

Gastrointestinal

Nausea, diarrhea, vomiting, dyspepsia, and abdominal pain are the most commonly reported adverse effects.

Central Nervous System

Headache, dizziness, tiredness, confusion, and convulsions. An increased risk of retinal detachment has also been reported. CNS effects are more likely in patients with pre-existing neurological conditions.

Hypersensitivity and Skin Reactions

Skin rash, pruritus (itching), and possible systemic allergic reactions. Rarely, Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN) have been reported. Discontinue treatment immediately if a severe skin reaction develops.

Musculoskeletal

Joint pain and arthropathy, particularly in younger patients. Fluoroquinolone-associated tendinitis and tendon rupture — most commonly affecting the Achilles tendon — have been reported, especially in elderly patients or those on corticosteroid therapy.

Metabolic and Endocrine

Risk of hypoglycemia, particularly when co-administered with antidiabetic medications. Blood glucose should be monitored during concurrent use.

Mental Health

Adverse mental health effects including anxiety, agitation, insomnia, and — rarely — hallucinations or psychosis have been reported. Patients experiencing mental health changes should seek immediate medical advice.

Photosensitivity

Mild and generally transient photosensitivity reactions have been reported. Patients should limit prolonged exposure to sunlight or UV light during treatment.

Hepatic Effects

Transient elevations in liver enzymes (SGOT/SGPT), serum bilirubin, urea, or creatinine levels, particularly in patients with pre-existing liver damage.

Pregnancy

Reproduction studies in mice, rats, and rabbits using both oral and parenteral administration did not reveal evidence of teratogenicity, impaired fertility, or impaired peri/postnatal development. However, like other fluoroquinolones, Quintor 500 mg has been shown to cause arthropathy in immature animals. For this reason, its use during pregnancy is not recommended. It should only be considered when no safer alternative is available and the potential benefit to the mother clearly outweighs the risk to the fetus.

Lactation

Studies in rats have confirmed that Quintor 500 mg is secreted in milk. Administration to nursing mothers is therefore not recommended. If treatment is essential for the mother, breastfeeding should be discontinued for the duration of therapy.

CNS Disorders and Seizure Risk

Quintor 500 mg should be used with caution in patients with suspected or known CNS disorders such as arteriosclerosis, epilepsy, or any other condition that predisposes to seizures and convulsions, as Quintor 500 mg may lower the seizure threshold.

Tendon Rupture Risk

Fluoroquinolones, including Quintor 500 mg, have been associated with tendinitis and tendon rupture, most commonly affecting the Achilles tendon. Risk is increased in elderly patients, those taking corticosteroids, and recipients of kidney, heart, or lung transplants. Quintor 500 mg should be discontinued immediately at the first sign of tendon pain, swelling, or inflammation.

Hydration

Patients should be advised to drink plenty of fluids during Quintor 500 mg therapy to maintain adequate hydration and prevent crystalluria (crystal formation in the urine).

Antacid and Supplement Timing

Magnesium/aluminum antacids, sucralfate, and products containing calcium, iron, or zinc should be taken at least 2 hours after or 6 hours before Quintor 500 mg to prevent reduced drug absorption.

Dairy and Calcium Interactions

Quintor 500 mg should not be taken simultaneously with milk or yogurt alone, as absorption may be significantly reduced. Dietary calcium taken as part of a regular meal does not significantly affect absorption.

Driving and Operating Machinery

Dizziness and confusion may occur during treatment. Patients should assess their response to Quintor 500 mg before driving or operating heavy machinery.

Superinfection

Prolonged use of Quintor 500 mg may promote overgrowth of non-susceptible organisms, including Clostridium difficile, which can cause antibiotic-associated colitis. Treatment should be discontinued promptly if severe or persistent diarrhea develops, and appropriate management should be initiated.

Photosensitivity

Patients should be advised to avoid prolonged exposure to direct sunlight or UV light during treatment, as photosensitivity reactions may occur.

There is no specific antidote for Quintor 500 mg overdose. Overdosage may lead to the following:

• Seizures and hallucinations
• Confusion and abdominal discomfort
• Renal and hepatic impairment
• Crystalluria (crystal formation in the urine) and hematuria (blood in urine)
• Reversible renal toxicity

Management is symptomatic and supportive. Adequate hydration should be maintained to prevent crystalluria. In cases of suspected overdose, contact a poison control center or seek emergency medical care immediately. Quintor 500 mg is not efficiently removed by hemodialysis or peritoneal dialysis.

• Store below 30°C, protected from direct light and moisture.
• Keep out of the reach of children.
• Do not use the medicine beyond the expiry date printed on the packaging.
• Store oral suspension in a cool, dry place. Do not refrigerate unless specifically instructed on the label.
• Once reconstituted, oral suspension should be used within the period specified by the manufacturer.

Pediatric Patients

Although Quintor 500 mg has shown clinical efficacy in trials involving children, it is not the first-line drug of choice in the pediatric population. Its use should be limited to situations where no safer, equally effective alternative exists, due to the potential risk of arthropathy in weight-bearing joints of growing children and adolescents.

Elderly Patients

No dosage adjustment is required based on age alone. However, renal function should be assessed, as age-related decline in kidney function may affect drug clearance and increase the risk of adverse effects.

Patients with Renal Impairment

Dose reduction is recommended only in cases of severe renal impairment (creatinine clearance <20 mL/minute or serum creatinine >265 µmol/L). Monitoring of serum drug levels is advisable to guide accurate dose adjustment.

Patients with Hepatic Impairment

Quintor 500 mg should be used with caution in patients with pre-existing liver disease. Liver enzyme levels should be monitored during prolonged therapy, as transient elevations in hepatic function tests have been reported.