Azithromycin Tablets

Below is a comprehensive article on Azithromycin tablets, along with available information about Zencus Pharma (a company that markets or distributes azithromycin in India). This is for informational purposes only; always follow your physician’s advice and local regulatory guidelines.

 

What is Azithromycin?

• Azithromycin is a macrolide (specifically, an azalide) antibiotic. It is used to treat a variety of bacterial infections by inhibiting bacterial protein synthesis, thereby stopping bacterial growth.
• It does not work against viral infections (e.g. common cold, flu).
• Azithromycin has good tissue penetration and a relatively long half-life, which allows for less frequent dosing in many cases.

Mechanism of Action

• Azithromycin binds to the 50S ribosomal subunit of susceptible bacteria, interfering with translocation of peptides, thereby inhibiting protein synthesis.
• Because of its structure (an azalide rather than a classical macrolide), it has improved acid stability and somewhat different pharmacokinetic behavior compared to older macrolides like erythromycin.

Indications (When It Is Used)

Azithromycin tablets are indicated for mild to moderate infections where the causative bacteria are susceptible. Common indications include:

Limitation of use: It should not be used for pneumonia in patients who are too ill for oral therapy or if bacteria are known or suspected to be resistant. Also, to reduce antibiotic resistance, it should be used only when a bacterial infection is confirmed or strongly suspected.

Dosage & Administration

The dose and duration depend on the infection, severity, age, renal/hepatic function, and local guidelines. Below are typical regimens (these are illustrative; actual prescription may differ):

Adults

• Community-acquired pneumonia, skin infections, etc.500 mg on Day 1, followed by 250 mg once daily on Days 2–5
• Acute bacterial sinusitis500 mg once daily for 3 days
• Urethritis / cervicitis (due to Chlamydia, etc.)A single 1 g (1000 mg) dose is often used
• Genital ulcer disease (chancroid)Also often 1 g single dose in men
• Prophylaxis of MAC in HIV1200 mg once weekly

Children / Pediatric Patients

Dosing is typically weight-based. For example:

• For community-acquired pneumonia in children ≥ 6 months: 10 mg/kg once on Day 1, then 5 mg/kg once daily on Days 2–5
• For pharyngitis/tonsillitis in those ≥ 2 years, similar regimens may be used.

Route & Absorption / Pharmacokinetics

• Azithromycin tablets are taken orally.
• Absorption is moderate; taking with food may slow absorption but can reduce gastrointestinal upset.
• It distributes well into tissues, especially respiratory tissues.
• It has a relatively long half-life, which supports once-daily dosing and shorter courses.
• It is eliminated partly in bile / feces; renal elimination plays a smaller role.

Contraindications & Precautions

Contraindications

• Known hypersensitivity to azithromycin, erythromycin, or other macrolide antibiotics.
• Patients with pre-existing prolonged QT interval or serious arrhythmias. (Azithromycin is associated with risk of QT prolongation / abnormal cardiac rhythm)
• Caution in those with severe hepatic disease.

Precautions & Warnings

• Use with caution in patients with cardiac disease, electrolyte abnormalities (e.g. hypokalemia, hypomagnesemia) which may predispose to QT prolongation.
• In the elderly, more risk of cardiac side effects.
• Monitoring may be needed in patients with liver disease.
• There have been reports of cholestatic hepatitis, though rare.
• Use cautiously (or avoid) in patients with myasthenia gravis, as macrolides may exacerbate muscle weakness. (This is a warning for macrolides in general)
• Long-term or repeated use may increase the risk of Clostridioides difficile (C. diff) / pseudomembranous colitis.
• Discontinue if a serious allergic reaction occurs.

Side Effects & Adverse Reactions

Common and less common side effects include:

If you experience severe abdominal pain, persistent diarrhea (especially bloody), icterus (jaundice), palpitations, or signs of allergy (swelling, breathing difficulty), seek immediate medical attention.

Drug Interactions

Azithromycin has fewer drug interactions compared to some other macrolides, but interactions are still possible:

• Antacids containing aluminium or magnesium may reduce absorption.
• Drugs prolonging QT interval (e.g. antiarrhythmics) may have additive risk.
• Some statins or other drugs affecting cardiac rhythm may interact in terms of risk of arrhythmia.
• Because azithromycin is a relatively weak inhibitor of CYP3A4, its interactions are fewer than those of erythromycin or clarithromycin, but caution is still needed with strong CYP3A4 substrates.

Always tell your doctor about all other medicines (including over-the-counter) you are taking before starting azithromycin.

Use in Special Populations

• Pregnancy: Azithromycin is often considered relatively safe in pregnancy if benefit outweighs risk, but other safer antibiotics are preferred when possible.
• Breastfeeding: Azithromycin is excreted in breastmilk; dose adjustments and monitoring may be needed.
• Pediatric / infants: Safety in infants under 6 months (for certain indications) is not well established in some infections.
• Elderly: More susceptible to cardiac effects.
• Hepatic / renal impairment: Dose modifications may be needed depending on severity; monitor function.

Resistance & Stewardship

• Overuse or inappropriate use of azithromycin contributes to antibiotic resistance.
• It should be reserved for situations where bacterial infection is likely or confirmed.
• Some bacteria (e.g. certain strains of Streptococcus pneumoniae, Haemophilus influenzae) have shown increasing resistance to macrolides.
• Judicious prescribing and adherence to guidelines is essential.

Zencus Pharma & Their Role with Azithromycin

While there is not much detailed scientific literature specifically about Zencus Pharma and its formulations, here is a summary of what is publicly available:

• Zencus Pharma is a pharmaceutical wholesaler and trader based in Panchkula, Haryana, India. They list Azithromycin 500 mg Tablets IP among their products.
• They also produce or market a combination product Monozen-AZ, which contains Cefixime + Azithromycin + Lactic Acid Bacillus (i.e. an antibiotic combination with a probiotic) under their tablets range for PCD (propaganda cum distribution) franchise.
• On TradeIndia, they offer Azithromycin 200 mg liquid products.
• One of their marketed brands seems to be Azicus 500 MG Tablet 3 (Azithromycin 500 mg) under Zencus’s umbrella.

Because Zencus is a distributor / trader rather than a large global pharmaceutical manufacturer, details about their formulation, bioequivalence studies, or strict manufacturing protocols may not be publicly published. If you need more technical data (e.g. stability, excipients, bioavailability) for a specific Zencus product, you may need to check their product authorization documents or contact them directly.

Practical Advice & Patient Counseling

• Take exactly as prescribed; do not skip doses or stop early, even if you feel better, unless advised by your doctor.
• Take with a full glass of water.
• If gastric upset occurs, taking with food may help (unless instructed otherwise).
• Avoid co-administration with antacids (or space them out) to prevent reduced absorption.
• Monitor for side effects: gastrointestinal symptoms, signs of allergy, abnormal heart rhythm symptoms (palpitations, dizziness).
• For diarrhea after stopping, especially if severe or bloody, inform the physician (possible Clostridioides difficile).
• Keep medications out of reach of children.
• If you are pregnant, breastfeeding, or have liver/heart disease, inform your prescriber before use.