ROXITHROMYCIN-WGR

What it is

Roxithromycin is a semisynthetic macrolide antibiotic. It is bacteriostatic at low concentrations and bactericidal at high concentrations, binding to the 50S subunit of the 70S ribosome and thereby disrupting bacterial protein synthesis. ROXITHROMYCIN-WGR is available as 150 mg and 300 mg tablets.

Approved indications

**Adults** — Acute pharyngitis, tonsillitis and sinusitis. — Acute bronchitis and acute exacerbations of chronic bronchitis; community acquired pneumonia. — Skin and skin structure infections. — Non-gonococcal urethritis. **Children** — Acute pharyngitis, acute tonsillitis, impetigo.

Dosing overview

The recommended dosage is 300 mg per day. This may be given as one 300 mg tablet daily, or one 150 mg tablet twice daily, or two 150 mg tablets once daily. For atypical pneumonia, the recommended dosage is 150 mg twice daily. The usual duration of treatment is five to ten days depending on the indication and clinical response. Streptococcal throat infections require at least ten days of therapy. Roxithromycin should be taken at least 15 minutes before food or on an empty stomach (more than three hours after a meal). In children, roxithromycin is administered twice daily at a dose of 5 to 8 mg/kg/day. The usual duration of treatment is five to ten days depending on the indication and clinical response, with streptococcal throat infections requiring ten days of therapy.

Key safety warnings

Antibiotic-associated pseudomembranous colitis has been reported with many antibiotics, with a toxin produced by *Clostridium difficile* appearing to be the primary cause. The severity of colitis may range from mild to life threatening. It is important to consider this diagnosis in patients who develop diarrhoea or colitis in association with antibiotic use, which may occur up to several weeks after cessation of antibiotic therapy. Cases of severe bullous skin reactions such as Stevens Johnson Syndrome or Toxic Epidermal Necrosis have been reported with roxithromycin. If symptoms or signs of SJS or TEN (such as progressive skin rash often with blisters or mucosal lesions) are present, roxithromycin treatment should be discontinued. Ventricular arrhythmias associated with prolonged QT interval, including ventricular tachycardia and torsades de pointes have been reported with macrolide antibiotics including roxithromycin. Risk of QT prolongation should be considered when weighing risks and benefits for at-risk groups including patients predisposed to QT prolongation such as those with a history of torsades de pointes or congenital long QT syndrome; patients taking other medication known to prolong the QT interval; patients with electrolyte disturbance, particularly hypokalaemia and hypomagnesaemia; and patients with clinically relevant bradycardia, cardiac arrhythmia or cardiac insufficiency. Severe vasoconstriction (ergotism) with possibly necrosis of the extremities has been reported when macrolide antibiotics have been associated with vasoconstrictive ergot alkaloids. Increased INR levels have been reported in patients when roxithromycin and coumarin anticoagulants are used concomitantly, and patients using roxithromycin and coumarin anticoagulants should be closely monitored.

Contraindications

Known hypersensitivity to macrolides, including erythromycin. Severely impaired hepatic function. Concomitant therapy with vasoconstrictive ergot alkaloids.

PBS listing

Information regarding PBS listing for ROXITHROMYCIN-WGR is not available in the provided documents.

Regulatory history

ROXITHROMYCIN-WGR 150 mg and 300 mg tablet blister packs were first listed on the ARTG on 4 May 2020 under licence category RE.