Zetamax Cap(Azithromycin)250 mg, 6’s-Potential Overview

Generic Information

• Brand Name: Zetamax Cap
• Generic Name: Azithromycin
• Strength: 250 mg per capsule, pack of 6
• Pharmaceutical Class:
  • Class: Macrolide Antibiotic
  • Type: Antibacterial

Indications for Use

Azithromycin is used to treat a variety of bacterial infections, including:

1. Respiratory Tract Infections:
   • Acute bacterial sinusitis
   • Acute bronchitis
   • Community-acquired pneumonia
2. Ear Infections:
   • Acute otitis media (middle ear infection)
3. Skin and Soft Tissue Infections:
   • Infections such as impetigo and cellulitis caused by susceptible bacteria.
4. Sexually Transmitted Infections:
   • Chlamydia trachomatis and gonorrhea
5. Other Infections:
   • Lyme disease
   • Traveler’s diarrhea
   • Helicobacter pylori eradication (in combination therapy)

Common Side Effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Headache
• Dizziness
• Fatigue

Serious Side Effects (Less Common)

• Cardiovascular:
  • QT interval prolongation, which can lead to life-threatening arrhythmias, including torsades de pointes.
• Hepatic:
  • Liver dysfunction, hepatitis, jaundice, and even liver failure in rare cases.
• Gastrointestinal:
  • Severe diarrhea, which may indicate Clostridium difficile infection (CDI), an intestinal condition.
• Hypersensitivity Reactions:
  • Rash, angioedema, anaphylaxis, difficulty breathing.
• Hearing Loss:
  • Rare but reversible hearing impairment, especially at high doses or prolonged use.

Dosage and Usage Instructions

1. For Respiratory and Ear Infections (Adults):
   • Typically, 500 mg on the first day, followed by 250 mg once daily for 4 more days.
2. For Gonorrhea and Chlamydia (Adults):
   • 1 g as a single dose.
3. For Skin and Soft Tissue Infections (Adults):
   • 500 mg on the first day, followed by 250 mg once daily for 4–5 more days.

Usage Instructions:

• Azithromycin should be taken with or without food.
• It is best taken with a full glass of water.
• Complete the entire prescribed course to prevent antibiotic resistance.
• If you miss a dose, take it as soon as you remember unless it’s almost time for the next dose. Do not take two doses at once.

Drug Interactions

• With Food:
  • Azithromycin can be taken with or without food, although food may reduce stomach irritation.
• With Other Medications:
  • Antacids: Azithromycin absorption may be reduced by antacids containing aluminum or magnesium. It is recommended to take azithromycin 2 hours before or after taking an antacid.
  • CYP3A4 Inhibitors: Drugs like ketoconazole, erythromycin, or grapefruit juice can increase azithromycin levels in the body.
  • Warfarin: Azithromycin may enhance the anticoagulant effect of warfarin, increasing the risk of bleeding. Close monitoring of prothrombin time is advised.
• Other Interactions:
  • Use caution with drugs that affect heart rhythm (e.g., antiarrhythmics) due to the risk of QT prolongation and torsades de pointes.

Regulatory Approval and Manufacturer

• Regulatory Approval:
  • Azithromycin is approved by the FDA and other global regulatory bodies for use in treating a wide range of bacterial infections.
• Manufacturer:
  • Manufactured by various pharmaceutical companies, and may be marketed under different brand names, such as Zetamax, in different regions.

Pharmacist-Related Data

Drug Name and Chemical Details

• Generic Name: Azithromycin
• Chemical Formula: C38H72N2O12
• Molecular Weight: 749.0 g/mol

Pharmacodynamics

1. Mechanism of Action:
   • Azithromycin is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. This blocks the elongation of the protein chain, preventing bacterial growth.
   • It has bacteriostatic effects at lower concentrations and bactericidal effects at higher concentrations, especially against actively dividing bacteria.
2. Therapeutic Effects:
   • Azithromycin is effective against a broad spectrum of bacteria, including Gram-positive, Gram-negative, and atypical organisms.
   • It is particularly useful in treating respiratory infections, skin infections, and STDs due to its effectiveness against common pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, Chlamydia trachomatis, and Neisseria gonorrhoeae.

Pharmacokinetics

1. Absorption:
   • Azithromycin is rapidly absorbed after oral administration, with peak plasma concentrations occurring within 2–3 hours.
   • The bioavailability is approximately 37%, but it is extensively distributed into tissues, particularly those of the lungs, tonsils, and prostate.
2. Distribution:
   • Azithromycin has a large volume of distribution (approximately 31 L/kg), meaning it is widely distributed throughout body tissues.
   • Protein binding is about 50%.
3. Metabolism:
   • Azithromycin undergoes limited metabolism in the liver, primarily via the CYP3A4 enzyme system, with only a small fraction of the drug being metabolized.
4. Excretion:
   • Azithromycin is predominantly excreted in the bile (approximately 50% of the dose), with a small amount excreted unchanged in the urine (about 6%).
5. Half-Life:
   • The elimination half-life is approximately 68 hours, which allows for once-daily dosing and short-course treatment for many infections.

Drug Interactions

1. With Food:
   • Azithromycin may be taken with or without food. However, taking it with food may reduce stomach upset in some patients.
2. With Other Medications:
   • Antacids: Taking antacids with azithromycin can reduce its absorption. It is recommended to space out the doses by at least 2 hours.
   • CYP3A4 Inhibitors: Drugs like ketoconazole, erythromycin, and certain antifungals may increase the blood levels of azithromycin.
   • Warfarin: Azithromycin can increase the anticoagulant effects of warfarin, requiring close monitoring of INR and prothrombin time.
3. Other Interactions:
   • QT-Prolonging Drugs: Azithromycin should be used cautiously with other drugs that prolong the QT interval, such as certain antiarrhythmics, due to the risk of arrhythmias.

Clinical Considerations

1. Pregnancy Category:
   • FDA Category B: Azithromycin is considered safe during pregnancy based on animal studies, but there are no adequate and well-controlled studies in humans. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
2. Lactation:
   • Azithromycin is excreted into breast milk in small amounts. It is generally considered safe for use during breastfeeding, but the infant should be monitored for any adverse effects.
3. Pediatric Use:
   • Azithromycin is used in children for the treatment of ear infections, pneumonia, and other bacterial infections. The dosage should be adjusted based on weight and age.
4. Geriatric Use:
   • Caution is advised when prescribing azithromycin to elderly patients, particularly those with pre-existing heart conditions, due to the risk of QT prolongation and arrhythmias.
5. Other Considerations:
   • Patients with liver dysfunction or severe renal impairment should be monitored closely.
   • Azithromycin should be used with caution in patients with a history of gastrointestinal conditions such as colitis.
   • Because of its long half-life, azithromycin can be administered as a short-course therapy, which can be convenient for patients.