birch triterpenes (Rx)

1-10%

Application site reactions (7.3%); placebo gel (6.1%)

Contraindications

None

Cautions

Hypersensitivity

• Local hypersensitivity and skin reactions reported, including urticaria and dermatitis
• If signs and symptoms of local or systemic hypersensitivity occur, discontinue immediately and initiate appropriate therapy

Pregnancy

Data are unavailable regarding use in pregnant females to evaluate for drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes

Systemic absorption in humans is low following topical administration and maternal use is not expected to result in fetal drug exposure

Animal studies

• Oral administration to pregnant rats during organogenesis had no effects on reproductive or fetal parameters

Lactation

Data are unavailable regarding presence of birch triterpenes or metabolites in human milk, effects on breastfed infants, or effect on milk production

No effects on breastfed infants are anticipated since systemic exposure would be low

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

Extract from birch bark rich in betulin

Mechanism of action in the treatment of wounds associated with epidermolysis bullosa is unknown

Absorption

Peak plasma concentration (betulin), Day 90: 33 ng/mL (adults); 207 ng/mL (children)

Distribution

Protein bound (betulin): >99%

Metabolism

Not fully characterized; in vitro, betulin was mainly metabolized by cytochrome P450 (CYP)3A

Topical Preparation

Wash hands before and after applying or wear gloves for application

Colorless to slightly yellowish, opalescent, non-aqueous gel

Topical Administration

For topical use only; not for use on mucous membranes (oral, intravaginal, or intra-anal); not for ophthalmic use

Avoid contact of gel with eyes and mucous membranes (eg, mouth, vagina, anus)

Apply a 1 mm layer to affected wound surface only

Do not rub in gel; cover wound with a sterile non-adhesive wound dressing

Alternatively, apply gel directly to dressing so that the topical gel is in direct contact with the wound

Reapply to cleansed wounds with wound dressing changes until wound is healed

If a treated wound becomes infected, discontinue treatment to that wound until infection has resolved

Each tube is for one-time use only

Once tube is opened, use product immediately

Discard after use in household trash or through a drug take back site, if available

In case of accidental contact, irrigate area with water

Storage

Store at 20-25ºC (68-77ºF); excursions permitted to 15-30ºC (59-86ºF)

Do not freeze