Roxithromycin is a semi-synthetic macrolide antibiotic derived from erythromycin, designed to offer enhanced stability, improved pharmacokinetics, and a broad spectrum of activity against common bacterial pathogens. It functions by inhibiting bacterial protein synthesis through binding to the 50S ribosomal subunit, effectively halting microbial growth. Clinically valued for its reliable bioavailability and convenient once- or twice-daily dosing, roxithromycin is widely prescribed for respiratory, skin, and soft tissue infections. Its favorable tolerability profile and minimal drug interactions make it a practical choice in outpatient and community settings.

Features

• Semi-synthetic 14-membered macrolide antibiotic
• Broad-spectrum activity against Gram-positive and some Gram-negative bacteria
• High oral bioavailability (>70%)
• Stable in acidic gastric environments
• Long elimination half-life (approximately 12 hours)
• Available in 150 mg and 300 mg tablet formulations

Benefits

• Effectively treats respiratory tract infections, including pharyngitis, sinusitis, and bronchitis
• Convenient dosing regimen supports patient adherence
• Generally well-tolerated with a lower incidence of gastrointestinal side effects compared to older macrolides
• Suitable for patients with penicillin allergies
• Demonstrates anti-inflammatory properties in addition to antibacterial effects
• Cost-effective therapeutic option for common community-acquired infections

Common use

Roxithromycin is indicated for the treatment of mild to moderate bacterial infections caused by susceptible organisms. Common clinical applications include upper and lower respiratory tract infections such as acute bacterial pharyngitis, tonsillitis, acute sinusitis, acute bronchitis, and community-acquired pneumonia. It is also effective for skin and soft tissue infections including erysipelas, impetigo, and secondary infected dermatoses. Additionally, roxithromycin may be used in the management of genitourinary infections caused by Chlamydia trachomatis and for dental infections involving oral anaerobic bacteria.

Dosage and direction

The standard adult dosage is 300 mg daily, administered either as a single dose or in two divided doses of 150 mg every 12 hours. For severe infections, the dose may be increased to 300 mg twice daily. Treatment duration typically ranges from 5 to 10 days depending on the type and severity of infection. The tablets should be swallowed whole with a full glass of water and may be taken with or without food, though administration with food may reduce potential gastrointestinal discomfort. Dosage adjustment is recommended in patients with severe hepatic impairment. Pediatric dosing is based on body weight at 2.5–5 mg/kg twice daily, up to a maximum of 300 mg daily.

Precautions

Use with caution in patients with pre-existing liver dysfunction, as roxithromycin is primarily metabolized hepatically. Periodic liver function tests are advisable during prolonged therapy. Caution is warranted in patients with known QT prolongation or those taking other medications that prolong the QT interval due to potential arrhythmogenic effects. Use during pregnancy should only be considered if the potential benefit justifies the potential risk to the fetus. Breastfeeding mothers should consult their physician, as roxithromycin is excreted in human milk. Superinfection with resistant bacteria or fungi may occur with prolonged use.

Contraindications

Roxithromycin is contraindicated in patients with known hypersensitivity to macrolide antibiotics or any component of the formulation. It should not be used concomitantly with ergot derivatives, cisapride, pimozide, or terfenadine due to potentially serious drug interactions. Contraindicated in patients with history of hepatitis associated with previous macrolide use. Should not be administered to patients with severe hepatic impairment without close monitoring.

Possible side effect

The most commonly reported adverse reactions are gastrointestinal in nature, including nausea (3–4%), abdominal pain (2%), diarrhea (2%), and vomiting (1%). Less frequent side effects include headache, dizziness, and skin rash. Rare but serious adverse effects may include hepatotoxicity (elevated liver enzymes, hepatitis), QT interval prolongation, pseudomembranous colitis, and allergic reactions ranging from urticaria to anaphylaxis. Transient hearing loss has been reported with high doses or in patients with renal impairment.

Drug interaction

Roxithromycin may increase plasma concentrations of drugs metabolized by CYP3A4, including warfarin (monitor INR), theophylline, carbamazepine, cyclosporine, and digoxin. Concomitant use with statins may increase risk of myopathy. Potentially serious interactions occur with ergot alkaloids (ergotism), cisapride (cardiac arrhythmias), and colchicine (increased toxicity). Antacids and H2-receptor antagonists may slightly decrease roxithromycin absorption. Coadministration with other QT-prolonging agents may increase arrhythmia risk.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, skip the missed dose and resume the regular dosing schedule. Do not double the dose to make up for a missed administration. Maintaining consistent antibiotic levels is important for therapeutic efficacy, so patients should be advised to establish a routine for medication intake.

Overdose

Symptoms of overdose may include severe nausea, vomiting, diarrhea, and abdominal pain. In severe cases, hearing loss, hepatotoxicity, or QT prolongation may occur. Management is primarily supportive with gastric lavage if presented early. There is no specific antidote. Electrolyte imbalances should be corrected, and cardiac monitoring is recommended in cases of significant overdose. Hemodialysis is not effective for removal of roxithromycin due to high protein binding.

Storage

Store at room temperature (15–30°C) in a dry place protected from light and moisture. Keep in the original container with the lid tightly closed. Do not store in bathroom or kitchen where humidity fluctuations occur. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging. Discard any tablets that show signs of physical deterioration.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any new medication or making changes to existing treatment. The prescribing physician should be aware of the patient’s complete medical history and current medications. Dosage and treatment duration should be determined by a healthcare provider based on individual patient factors and local susceptibility patterns.

Reviews

Clinical studies demonstrate roxithromycin’s efficacy with clinical cure rates of 85–95% in respiratory infections. Physicians appreciate its convenient dosing schedule and generally favorable side effect profile. Patients report good tolerance with fewer gastrointestinal disturbances compared to erythromycin. Some studies note emerging resistance in certain geographic regions, emphasizing the need for appropriate susceptibility testing. Overall, roxithromycin remains a valuable option in the macrolide class for treating common community-acquired infections.