Azithrocin 500

Indications

Azithrocin treats various infections caused by susceptible organisms, including lower respiratory tract infections like bronchitis and pneumonia, upper respiratory tract infections such as sinusitis and pharyngitis/tonsillitis, otitis media, and skin and soft tissue infections. It is also effective in treating sexually transmitted diseases, specifically non-gonococcal urethritis and cervicitis due to Chlamydia trachomatis in both men and women.

Pharmacology

Azithromycin is stable in acidic environments, making it suitable for oral intake without needing protection from gastric acids. Its absorption is optimal on an empty stomach, peaking in concentration within 2.1 to 3.2 hours post-administration. Azithromycin accumulates significantly in phagocytes and is released actively at infection sites, achieving tissue concentrations over 50 times higher than in plasma. It has a prolonged half-life due to extensive tissue uptake and release, with a terminal elimination half-life of 68 hours. The drug is primarily excreted unchanged via bile, with approximately 6% excreted in urine over a week. Azithromycin functions by binding to the 50S ribosomal subunit of microorganisms, inhibiting protein synthesis but not affecting nucleic acid synthesis. It is effective against a broad range of gram-positive and gram-negative bacteria, as well as other microorganisms like Chlamydia and Mycoplasma species.

Dosage

• Oral:
  • Adults: 500 mg once daily for 3 days, or 500 mg on day 1 followed by 250 mg daily for the next 4 days. For sexually transmitted diseases, a single 1 gm dose or 500 mg on day 1 followed by 250 mg daily for 2 days.
  • Children: 10 mg/kg once daily for 3 days for those over 6 months. Dosage varies by weight.
  • Typhoid Fever: 500 mg once daily for 7-10 days.
• Injection (IV Infusion only):
  • Community-Acquired Pneumonia: 500 mg daily via IV for at least 2 days, followed by 500 mg orally to complete a 7-10 day course.
  • Pelvic Inflammatory Disease: 500 mg daily via IV for 1-2 days, followed by 250 mg orally for a 7-day course.

Interaction

Azithromycin should be taken 1 hour before or 2 hours after antacids. Caution is advised when co-administering with cyclosporin, digoxin, ergot derivatives, and other medications like methylprednisolone, theophylline, and warfarin, due to potential interaction effects.

Contraindications

Azithromycin is contraindicated in patients with hypersensitivity to macrolide antibiotics and those with hepatic diseases. It should not be co-administered with ergot derivatives.

Side Effects

Common side effects include gastrointestinal issues like nausea, abdominal pain, vomiting, and diarrhea. Allergic reactions, liver enzyme elevations, and hearing impairment (at higher doses) are rare but possible.

Pregnancy & Lactation

Classified as Pregnancy Category B. While animal studies show no harm, there are no adequate human studies. Caution is advised when administering to nursing women.

Precautions & Warnings

Rare but serious allergic reactions, including anaphylaxis, have been reported. Patients with renal or hepatic impairment require cautious use.

Use in Special Populations

No dose adjustment for mild renal impairment, but caution for severe cases. Not recommended for patients with hepatic disease.

Overdose Effects

Symptoms of overdose include hearing loss, severe nausea, vomiting, and diarrhea. Supportive measures and gastric lavage are recommended.

Storage Conditions

Store in a dry place, away from light and heat, and out of reach of children.