ALTABAX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ALTABAX (ALTABAX).
Retapamulin is a pleuromutilin antibiotic that selectively inhibits bacterial protein synthesis by interacting with the 50S ribosomal subunit, specifically at the L3 ribosomal protein and the peptidyl transferase center, thereby preventing peptide bond formation.
| Metabolism | Retapamulin undergoes hepatic metabolism primarily via cytochrome P450 (CYP) isoenzymes, including CYP3A4, and is excreted in feces and urine. |
| Excretion | Retapamulin is primarily eliminated via the fecal route (96.5% of dose), with minimal renal excretion (<0.5% of dose). |
| Half-life | Terminal half-life is approximately 11-14 hours in adults after topical application, supporting twice-daily dosing. |
| Protein binding | Retapamulin is approximately 94% bound to human plasma proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution after IV administration is approximately 3.1 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Systemic bioavailability after topical application is low and highly variable, with mean values <2% in adults. |
| Onset of Action | Onset of clinical improvement is typically within 24-48 hours of first application. |
| Duration of Action | Duration of action is 12 hours, consistent with twice-daily application; treatment course is 5 days. |
1% ointment applied topically to affected area twice daily for 5 days. Total treatment area should not exceed 100 cm². Maximum single dose is 0.5 g per 100 cm².
| Dosage form | OINTMENT |
| Renal impairment | No dose adjustment required for renal impairment as systemic absorption is negligible. |
| Liver impairment | No dose adjustment required for hepatic impairment as systemic absorption is negligible. |
| Pediatric use | Children 9 months and older: Apply 1% ointment to affected area twice daily for 5 days. Maximum treatment area 100 cm². For children under 9 months: safety and efficacy not established. |
| Geriatric use | No specific dose adjustment required. Use same as adult dosing due to minimal systemic absorption. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ALTABAX (ALTABAX).
| Breastfeeding | Not known if retapamulin is excreted in human milk. Systemic absorption is negligible after topical use, so risk to infant is likely low. M/P ratio not determined. Caution if applied to breast area to avoid infant ingestion. |
| Teratogenic Risk | No adequate and well-controlled studies in pregnant women. Animal studies: oral doses up to 50 mg/kg/day in rats (0.8 times MRHD based on AUC) and 40 mg/kg/day in rabbits (1.6 times MRHD) showed no fetal harm. However, systemic absorption after topical application is minimal, so fetal exposure is negligible. Risk cannot be ruled out; classify as pregnancy category B. |
■ FDA Black Box Warning
No black box warnings.
| Serious Effects |
["Hypersensitivity to retapamulin or any component of the formulation."]
| Precautions | ["Not for use on mucous membranes (e.g., eyes, mouth, vagina).","May cause application site reactions (e.g., pruritus, erythema, pain).","Clostridium difficile-associated diarrhea (CDAD) has been reported with nearly all antibacterial agents, including retapamulin.","Prolonged use may result in overgrowth of nonsusceptible organisms."] |
| Food/Dietary | None known. Topical application with negligible systemic absorption; no dietary restrictions. |
| Clinical Pearls |
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| Fetal Monitoring | No specific monitoring required beyond routine prenatal care due to minimal systemic absorption. Monitor for local skin reactions or signs of infection. |
| Fertility Effects | No studies on fertility in humans. Animal studies: no adverse effects on fertility or mating index in rats at oral doses up to 50 mg/kg/day (0.8 times MRHD). Unlikely to affect fertility due to negligible systemic absorption. |
| Retapamulin (Altabax) is a topical pleuromutilin antibiotic indicated for impetigo due to S. aureus or S. pyogenes. Apply to lesions twice daily for 5 days. Avoid contact with eyes, mouth, or mucous membranes. No systemic absorption significant; safe for use in children ≥9 months. Do not use on open wounds or burns. Monitor for local irritation; discontinue if hypersensitivity occurs. |
| Patient Advice | Apply a thin layer to the affected area twice daily for 5 days, even if symptoms improve. · Wash hands before and after application unless treating hand lesions. · Do not cover the area with bandages unless instructed by your doctor. · Avoid getting the ointment in your eyes, nose, mouth, or on vaginal area. · Stop use and inform your doctor if you develop severe irritation, redness, or swelling. · Store at room temperature away from heat and moisture. |