Roxithromycin

Macrolide·Infectious Diseases - Macrolides & Tetracyclines

Community-acquired pneumonia, acute bronchitis, non-gonococcal urethritis, skin infections in penicillin-allergic patients

PBSMACROLIDERulide, Biaxin150 mg tabletS4+1

Max Dose

300 mg/day

Half-life

10 h

GI Upset

LESS THAN ERY

CYP Inhibitor

WEAK

Rapid Summary

Overview

Semi-synthetic macrolide. Designed to provide the atypical coverage of Erythromycin without the horrific GI cramps and severe CYP3A4 drug interactions.

Maximum Dose

Max 300 mg/day (e.g., 150 mg BD or 300 mg OD).

Clinical Focus

Significantly safer to co-prescribe with Statins and Warfarin compared to Clarithromycin, making it highly useful in the elderly.

Bottom Line

Roxithromycin is a macrolide antibiotic for respiratory and soft tissue infections with better GI tolerability than erythromycin, but still carries QTc prolongation and drug interaction risks.

Formulation & Access

Brand Names

Rulide, Biaxin

Oral Routes

Tablets (150 mg, 300 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Community-acquired pneumonia, acute bronchitis, non-gonococcal urethritis, skin infections in penicillin-allergic patients.

Clinical Place

A safer, highly tolerable alternative to Clarithromycin/Erythromycin in primary care.

Quick reference

Class & Role

Macrolide — Semi-synthetic macrolide.

Route / Formulation

Tablets (150 mg, 300 mg). (Rulide, Biaxin)

Usual Dose & Max

PO 150 mg BD OR 300 mg OD. Best taken 15 mins before food to maximize absorption. Max 300 mg/day (e.g., 150 mg BD or 300 mg OD).

Key Indication Doses

Atypical CAP / Mild Skin Infections: PO 150 mg BD OR 300 mg OD. Best taken 15 mins before food to maximize absorption. Renal Impairment: No strict dose reduction required in mild/moderate CKD (Hepatically cleared).

Best Uses

Roxithromycin is a macrolide antibiotic for respiratory and soft tissue infections with better GI tolerability than erythromycin, but still carries QTc prolongation and drug interaction risks.

Avoid / Cautions

Concurrent use of ergotamine derivatives. Baseline QTc > 500 ms. Pregnancy Category B1.

Key Risks

Gastrointestinal: Nausea, abdominal pain (significantly less severe than Erythromycin because it does not bind motilin receptors). Cardiovascular: QTc prolongation (inherent to all macrolides, but less pronounced). Hepatic: Transient transaminitis.

Key Interactions

It has very low affinity for CYP3A4 compared to Clarithromycin. It does not significantly spike levels of Atorvastatin, Warfarin, or DOACs, making it the macrolide of choice in polypharmacy.

Monitoring

Consider ECG if combining with other QTc prolonging drugs. No specific routine laboratory tests required.

Clinical Pearl

If an elderly patient is on 80mg Atorvastatin and develops a Mycoplasma pneumonia, giving them Clarithromycin will cause rhabdomyolysis. Switching the script to Roxithromycin avoids the interaction entirely and keeps the patient safe.

Access

Rulide, Biaxin150 mg tablet

Brand: Rulide, Biaxin
Formulation: Tablets (150 mg, 300 mg)

Roxithromycin

Macrolide·Infectious Diseases - Macrolides & Tetracyclines

Community-acquired pneumonia, acute bronchitis, non-gonococcal urethritis, skin infections in penicillin-allergic patients

PBSMACROLIDERulide, Biaxin150 mg tabletS4+1

Max Dose

300 mg/day

Half-life

10 h

GI Upset

LESS THAN ERY

CYP Inhibitor

WEAK

Rapid Summary

Overview

Semi-synthetic macrolide. Designed to provide the atypical coverage of Erythromycin without the horrific GI cramps and severe CYP3A4 drug interactions.

Maximum Dose

Max 300 mg/day (e.g., 150 mg BD or 300 mg OD).

Clinical Focus

Significantly safer to co-prescribe with Statins and Warfarin compared to Clarithromycin, making it highly useful in the elderly.

Bottom Line

Roxithromycin is a macrolide antibiotic for respiratory and soft tissue infections with better GI tolerability than erythromycin, but still carries QTc prolongation and drug interaction risks.

Formulation & Access

Brand Names

Rulide, Biaxin

Oral Routes

Tablets (150 mg, 300 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Community-acquired pneumonia, acute bronchitis, non-gonococcal urethritis, skin infections in penicillin-allergic patients.

Clinical Place

A safer, highly tolerable alternative to Clarithromycin/Erythromycin in primary care.

Quick reference

Class & Role

Macrolide — Semi-synthetic macrolide.

Route / Formulation

Tablets (150 mg, 300 mg). (Rulide, Biaxin)

Usual Dose & Max

PO 150 mg BD OR 300 mg OD. Best taken 15 mins before food to maximize absorption. Max 300 mg/day (e.g., 150 mg BD or 300 mg OD).

Key Indication Doses

Best Uses

Roxithromycin is a macrolide antibiotic for respiratory and soft tissue infections with better GI tolerability than erythromycin, but still carries QTc prolongation and drug interaction risks.

Avoid / Cautions

Concurrent use of ergotamine derivatives. Baseline QTc > 500 ms. Pregnancy Category B1.

Key Risks

Key Interactions

It has very low affinity for CYP3A4 compared to Clarithromycin. It does not significantly spike levels of Atorvastatin, Warfarin, or DOACs, making it the macrolide of choice in polypharmacy.

Monitoring

Consider ECG if combining with other QTc prolonging drugs. No specific routine laboratory tests required.

Clinical Pearl

Access

Rulide, Biaxin150 mg tablet

Brand: Rulide, Biaxin
Formulation: Tablets (150 mg, 300 mg)