Roxithromycin

Roxithromycin is a macrolide antibiotic used in some countries to treat susceptible bacterial infections (most commonly respiratory tract and some skin/soft tissue infections). It is an oral, prescription-only medicine.

What it is used for

Roxithromycin may be prescribed for bacterial infections caused by susceptible organisms, including certain upper and lower respiratory tract infections and some skin/soft tissue infections. It is not effective for viral illnesses (e.g., colds or flu).

How to take

In markets where it is approved, roxithromycin is typically taken by mouth once or twice daily, often at least 15 minutes before meals (food can reduce absorption). Follow your prescriber's directions and complete the full course unless told otherwise.

Roxithromycin vs other antibiotics

When doctors usually choose which

How it works

Roxithromycin is a macrolide antibiotic. It binds to the 50S ribosomal subunit and inhibits bacterial protein synthesis.

Side effects

Common side effects include nausea, abdominal pain, diarrhea, headache, and skin rash.

Stop the medicine and seek urgent medical care if you develop signs of a serious allergic reaction (e.g., swelling of the face/lips/tongue, difficulty breathing), severe skin reactions (blistering/peeling rash), severe or persistent diarrhea, or symptoms of liver injury (dark urine, yellowing of skin/eyes, severe fatigue).

Warnings and precautions

• Heart rhythm: rare cases of QT prolongation and serious arrhythmias have been reported with macrolides. Use extra caution if you have known QT prolongation, low potassium/magnesium, slow heart rate, or if you take other QT-prolonging medicines.
• Antibiotic-associated diarrhea: severe diarrhea (including C. difficile colitis) can occur during or after antibiotic therapy.
• Liver: liver injury has been reported rarely. Use caution in severe hepatic impairment and follow clinician advice.
• Kidney: rare cases of interstitial nephritis have been reported.

Drug-drug interactions

Tell your clinician/pharmacist about all medicines and supplements you take. Important interactions may include:

• Warfarin and other vitamin K antagonists: increased INR and bleeding have been reported; INR monitoring is recommended during combined use.
• Statins and fibrates: rare cases of muscle toxicity have been reported with interacting combinations; report muscle pain or weakness promptly.
• Theophylline: exposure may increase slightly; monitoring may be needed in some patients.
• QT-prolonging medicines: combined use can increase arrhythmia risk.

Special populations

• Pregnancy and breastfeeding: use only if prescribed. Small amounts may pass into breast milk; discuss risks/benefits with a clinician.
• Hepatic impairment: dose reduction may be recommended in severe hepatic impairment (clinician-directed).
• Renal impairment: for short courses, dose adjustment is often not required; severe impairment should be clinician-managed.
• Children: pediatric dosing is weight-based and should follow local product information and clinician guidance.

Pharmacokinetics

Roxithromycin has an absolute bioavailability of approximately 50%. Peak concentrations typically occur about 1–2 hours after dosing. Food can reduce absorption. It is highly protein-bound and distributes into tissues; small amounts may be found in breast milk. Elimination occurs via multiple routes (including fecal and urinary), with a reported half-life around 12 hours in healthy adults; the half-life may be prolonged in hepatic or renal impairment.

Off-label / investigational mentions

Some studies have explored macrolides (including roxithromycin) for conditions such as gingival overgrowth or cardiovascular prevention. These are not standard labeled indications.

Storage

Store below 25°C (77°F) in a cool, dry place. Protect from light and moisture. Keep out of reach of children.