Azithromycin – A Powerful Antibiotic You Should Know About

 *Introduction*

*Azithromycin* is a broad-spectrum *macrolide antibiotic* used to treat various *bacterial infections*. Known for its long half-life and once-daily dosing, it has become a popular choice for respiratory, skin, and sexually transmitted infections.

It was discovered in the 1980s and is now listed on the *WHO Model List of Essential Medicines*.

*Common Brand Names:*  

- *Zithromax*  

- *Azomax*  

- *Z-Pak*  

- *Azee*  

- *Zimax*

*Mechanism of Action*

Azithromycin works by *inhibiting bacterial protein synthesis*. It binds to the *50S ribosomal subunit* of the bacteria, preventing them from producing essential proteins, thus *stopping their growth* (bacteriostatic effect).

*Pharmacokinetics*

- *Absorption:* Rapid oral absorption; better on an empty stomach  

- *Distribution:* Widely distributed in tissues; concentrates well in lungs, skin, tonsils  

- *Half-life:* Long (approx. 68 hours), allowing once-daily dosing  

- *Metabolism:* Minimal hepatic metabolism  

- *Excretion:* Mostly via bile (feces), small amount via urine

*Indications*

Azithromycin is used to treat:

- *Respiratory tract infections* (bronchitis, pneumonia, sinusitis)  

- *Pharyngitis/tonsillitis*  

- *Skin and soft tissue infections*  

- *Sexually transmitted infections* (chlamydia, gonorrhea)  

- *Ear infections (otitis media)*  

- *Traveler’s diarrhea*  

- *Mycobacterial infections* (in HIV patients)

*Dosage*

*Adults:*

- *Typical dose:* 500 mg on day 1, followed by 250 mg once daily for 4 days  

- *STIs:* Single 1 g oral dose  

- *Pediatric dose:* 10 mg/kg on day 1, then 5 mg/kg once daily (based on weight and condition)

*Note:* Always follow physician’s instructions for exact dose and duration.

*Available Forms*

- *Tablets:* 250 mg, 500 mg  

- *Oral suspension:* 100 mg/5 mL, 200 mg/5 mL  

- *Capsules:* 250 mg  

- *IV injection:* For hospital use (severe infections)

*Contraindications*

- Known allergy to *macrolides*

- History of *cholestatic jaundice or hepatic dysfunction* after previous azithromycin use  

- Use caution in patients with *liver disease*, *heart rhythm disorders*, or *myasthenia gravis*

*Side Effects*

*Common:*

- Nausea, vomiting  

- Diarrhea  

- Abdominal pain  

- Headache

*Less common but serious:*

- QT prolongation (can cause arrhythmias)  

- Liver enzyme elevation  

- Allergic reactions (rash, anaphylaxis)  

- Clostridioides difficile-associated diarrhea

*Resistance Concerns*

Azithromycin resistance is growing due to *overuse and misuse*. Resistance has been reported in:

- *Streptococcus pneumoniae*  

- *Neisseria gonorrhoeae*  

- *Mycoplasma genitalium*

To reduce resistance:

- Use only when prescribed  

- Complete the full course  

- Avoid self-medication

*Conclusion*

*Azithromycin* remains a vital antibiotic due to its broad spectrum, long half-life, and convenient dosing. However, rising resistance emphasizes the need for *judicious use*. Always consult a healthcare provider before starting or stopping antibiotics.