Altabax (retapamulin)

What is Altabax, and how does it work?

Altabax is indicated for use in adults and pediatric patients aged 9 months and older for the topical treatment of impetigo (up to 100 cm² in total area in adults or 2% total body surface area in pediatric patients aged 9 months or older) due to Staphylococcus aureus (methicillinsusceptible isolates only) or Streptococcus pyogenes. Safety in patients younger than 9 months has not been established.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of
Altabax and other antibacterial drugs, Altabax should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.

What are the side effects of Altabax?

Clinical Studies Experience

Because clinical trials are conducted under varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The adverse reaction information from the clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates.

The safety profile of Altabax was assessed in 2,115 adult and pediatric subjects 9 months and older who used at least one dose from a 5-day, twice-a-day regimen of retapamulin ointment. Control groups included 819 adult and pediatric subjects who used at least one dose of the active control (oral cephalexin), 172 subjects who used an active topical comparator (not available in the US), and 71 subjects who used placebo.

Adverse events rated by investigators as drug-related occurred in 5.5% (116/2,115) of subjects treated with retapamulin ointment, 6.6% (54/819) of subjects receiving cephalexin, and 2.8% (2/71) of subjects receiving placebo.

The most common drug-related adverse events (greater than or equal to 1% of subjects) were

application site irritation (1.4%) in the retapamulin group,
diarrhea (1.7%) in the cephalexin group, and application site pruritus (1.4%) and
application site paresthesia (1.4%) in the placebo group.

Adults

The adverse events, regardless of attribution, reported in at least 1% of adults (aged 18 years and older) who received Altabax or comparator are presented in Table 1.

Table 1. Adverse Events Reported by ≥1% of Adult Subjects Treated with Altabax or Comparator in Phase 3 Clinical Trials

Adverse EventAltabax
N = 1,527
%Cephalexin
N = 698
%Headache2.02.0Application site irritation1.6<1.0Diarrhea1.42.3Nausea1.21.9Nasopharyngitis1.2<1.0Creatinine phosphokinase increased<1.01.0

Pediatrics

The adverse events, regardless of attribution, reported in at least 1% of pediatric subjects aged 9 months to 17 years who received Altabax are presented in Table 2.

Table 2. Adverse Events Reported by ≥1% in Pediatric Subjects Aged 9 Months to 17 Years Treated with Altabax in Phase 3 Clinical Trials

Adverse EventAltabax
N = 588
%Cephalexin
N = 121
%Placebo
N = 64
%Application site pruritus1.900Diarrhea1.75.00Nasopharyngitis1.51.70Pruritus1.51.01.6Eczema1.000Headache1.21.70Pyrexia1.2<1.01.6

Other Adverse Events

Application site pain, erythema, and contact dermatitis were reported in less than 1% of subjects in clinical trials.

Postmarketing Experience

In addition to reports in clinical trials, the following events have been identified during postmarketing use of Altabax. Because these events are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

General Disorders And Administration Site Conditions

Application site burning.

Immune System Disorders

Hypersensitivity including angioedema.

What is the dosage for Altabax?

A thin layer of Altabax should be applied to the affected area (up to 100 cm²
in total area in adults or 2% total body surface area in pediatric patients aged
9 months or older) twice daily for 5 days. The treated area may be covered with
a sterile bandage or gauze dressing if desired.

What drugs interact with Altabax?

Coadministration of oral ketoconazole 200 mg twice daily increased retapamulin geometric mean AUC(0-24) and Cmax by 81% after topical application of retapamulin ointment, 1% on the abraded skin of healthy adult males.
Due to low systemic exposure to retapamulin following topical application in adults and pediatric patients aged 2 years and older, dosage adjustments for retapamulin are unnecessary in these patients when coadministered with CYP3A4 inhibitors, such as ketoconazole.
Based on in vitro P450 inhibition studies and the low systemic exposure observed following topical application of
Altabax, retapamulin is unlikely to affect the metabolism of other P450 substrates.
Concomitant administration of retapamulin and CYP3A4 inhibitors, such as
ketoconazole, has not been studied in pediatric patients.
In pediatric subjects
aged 2 to 24 months, systemic exposure of retapamulin was higher compared with
subjects aged 2 years and older after topical application.
Based on the higher exposure of retapamulin, it is not recommended to coadminister
Altabax with strong CYP3A4 inhibitors in patients younger than 24 months.
The effect of concurrent application of Altabax and other topical products to the same area of skin has not been studied.

Is Altabax safe to use while pregnant or breastfeeding?

There are no available data on Altabax use in pregnant women to inform any drug associated risk for major birth defects, miscarriage or adverse maternal or fetal outcomes.
There are no data available on the presence of retapamulin in human milk, its effects on the breastfed infant or its effects on milk production.
However, breastfeeding is not expected to result in exposure of the child to the drug due to the negligible systemic absorption of retapamulin in humans following topical administration of
Altabax.