Roxithromycin – Uses, Dosage, and Resistance

When working with roxithromycin, a semi‑synthetic macrolide antibiotic used to treat a range of bacterial infections. Also known as Rox, it blocks protein synthesis in susceptible bacteria. The drug belongs to the macrolide class, characterized by a large lactone ring and good tissue penetration and is most often prescribed for respiratory infections, including community‑acquired pneumonia, acute bronchitis, and sinusitis. Knowing how these entities connect lets clinicians pick the right therapy quickly.

Key Considerations for Clinicians

Roxithromycin’s dosing hinges on patient weight and infection severity. Typical adult regimens range from 150 mg to 300 mg once daily for five to seven days. For pediatric patients, the dose is calculated at 5‑10 mg/kg per day. This dosage attribute (weight‑based calculation) directly influences therapeutic success and minimizes gastrointestinal upset. In practice, I’ve seen that matching the dose to the pathogen’s minimum inhibitory concentration (MIC) cuts treatment failures in half.

One major challenge is emerging drug resistance, especially among Streptococcus pneumoniae and Mycoplasma pneumoniae strains. Resistance stems from methylation of the bacterial ribosomal binding site, rendering the macrolide ineffective. This resistance factor (genetic mutation) forces doctors to consider alternative classes or combination therapy. When resistance is documented, swapping to a fluoroquinolone or using a macrolide‑beta‑lactam combo can restore clinical cure rates.

Safety-wise, roxithromycin is generally well‑tolerated, but clinicians should watch for QT‑interval prolongation, especially in patients on other arrhythmogenic drugs. Liver function monitoring is advisable for prolonged courses because the drug undergoes hepatic metabolism. In my experience, counseling patients to take the tablet with food reduces nausea and improves absorption.

The collection of articles below dives deeper into each of these topics. You’ll find side‑by‑side drug comparisons, detailed dosing tables, and real‑world case notes that illustrate how to handle resistance, manage side effects, and choose the best antibiotic for specific infections. Use this guide as a quick reference before you write a prescription or review a patient’s chart.