Zimax PFS 15ML

Indications

Zimax is recommended for treating infections caused by susceptible organisms. It effectively addresses lower respiratory tract infections like bronchitis and pneumonia, upper respiratory tract infections such as sinusitis and pharyngitis/tonsillitis, otitis media, as well as skin and soft tissue infections. In cases of sexually transmitted diseases in both men and women, Zimax is particularly indicated for the treatment of non-gonococcal urethritis and cervicitis caused by Chlamydia trachomatis.

Pharmacology

Azithromycin, being acid-stable, can be taken orally without protection from gastric acids. It is swiftly absorbed, with greater absorption observed on an empty stomach. In adults, the time to peak concentration for oral dosage forms ranges from 2.1 to 3.2 hours. Azithromycin’s high concentration in phagocytes enables active transportation to the site of infection, with significant release during active phagocytosis. Its tissue concentration can exceed plasma levels by over 50 times, owing to ion trapping and high lipid solubility.

Azithromycin’s extended half-life permits the administration of a large single dose, ensuring sustained bacteriostatic levels in infected tissue for several days. Following a single 500 mg dose, plasma concentrations decline in a polyphasic pattern with a mean apparent plasma clearance of 630 mL/min and a terminal elimination half-life of 68 hours. The prolonged half-life is attributed to extensive uptake and subsequent release of the drug from tissues. Biliary excretion, primarily unchanged, is a major elimination route, with approximately 6% of the administered dose appearing as unchanged drug in urine over a week.

Microbiology

Azithromycin acts by binding to the 50S ribosomal subunit of susceptible microorganisms, thus disrupting microbial protein synthesis without affecting nucleic acid synthesis. It has demonstrated activity against a wide range of microorganisms, including aerobic and facultative gram-positive and gram-negative bacteria, as well as certain anaerobic microorganisms.

Dosage

For adults, the recommended oral dosage is 500 mg once daily for 3 days or 500 mg once on day 1 followed by 250 mg once daily on days 2-5 for 4 days. In sexually transmitted diseases caused by Chlamydia trachomatis, a single dose of 1 gm or 500 mg once on day 1 followed by 250 mg once daily for the next 2 days may be administered.

For children, the dosage varies based on body weight and specific indications.

Azithromycin injection, for intravenous infusion only, is recommended for the treatment of certain infections in adult patients, with dosages specified accordingly.

Administration

The reconstitution procedure for the suspension involves shaking the bottle well to loosen the powder, adding boiled and cooled water up to the water mark of the bottle label, and shaking until the powder is completely mixed with water. Azithromycin should be taken at least 1 hour before or 2 hours after meals.

Interaction

Azithromycin’s interaction with other medications, such as antacids, carbamazepine, cyclosporine, digoxin, ergot derivatives, methylprednisolone, theophylline, warfarin, and terfenadine, should be carefully considered, and co-administration should be done cautiously, if necessary.

Contraindications

Azithromycin is contraindicated in patients hypersensitive to it or any other macrolide antibiotic, those with hepatic diseases, and when co-administered with ergot derivatives.

Side Effects

Zimax is generally well tolerated, with most observed side effects being mild to moderate. Gastrointestinal symptoms like nausea, abdominal discomfort, vomiting, and diarrhea are commonly reported. Allergic reactions, reversible liver transaminase elevations, and, rarely, cholestatic jaundice have been noted. Reversible hearing impairment has been reported in some cases of prolonged, high-dose usage.

Pregnancy & Lactation

Azithromycin is categorized as Pregnancy Category B, indicating no evidence of harm to the fetus based on animal studies. Caution is advised regarding its use during pregnancy and lactation, with administration recommended only if alternatives are unavailable and under medical supervision.

Precautions & Warnings

Rare serious allergic reactions have been reported, requiring prolonged observation and treatment. Caution should be exercised in patients with renal or hepatic impairment. Azithromycin is unlikely to affect a patient’s ability to drive or operate machinery.

Overdose Effects

Data on overdosage with Zimax are lacking. Typical symptoms of macrolide antibiotic overdosage include hearing loss, severe nausea, vomiting, and diarrhea. General supportive measures are recommended.

Storage Conditions

Zimax should be stored in a dry place away from light and heat, out of reach of children.