retapamulin (Rx)

1-10%

Application site irritation (2%)

Contraindications

None

Cautions

Not for oral, intranasal, ophthalmic or intravaginal use; efficacy and safety for mucosal surfaces not established

Discontinue if sensitization or severe local irritation develops

Epistaxis reported with use on nasal mucosa

Not evaluated on mucosal surfaces

Pregnancy

There are no available data on use in pregnant women to inform any drug associated risk for major birth defects, miscarriage or adverse maternal or fetal outcomes; drug is negligibly absorbed systemically following topical administration and maternal use is not expected to result in fetal exposure

Animal data

• Animal reproduction studies were not conducted with drug; however, in animal studies where drug was administered by oral gavage or intravenous infusion to pregnant rats and rabbits, respectively, during organogenesis, maternal toxicity was seen at doses ≥150 mg/kg/day and 7.2 mg/kg/day (8-fold the maximum achievable human exposure based on AUC) for oral and intravenous routes, respectively

Lactation

There are no data available on presence of drug in human milk, its effects on breastfed infant or on milk production; however, breastfeeding is not expected to result in exposure of child to drug due to negligible systemic absorption in humans following topical administration of drug

Developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed infant from drug or from underlying maternal condition

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

Pleuromutilin antibacterial; binds to 50S ribosomal subunit and inhibits bacterial protein synthesis, bateriostatic at MIC; bactericidal at 1000x MIC

Pharmacokinetics

Absorption: Low

Protein Bound: 94%

Metabolism: in vitro by liver CYP3A4