Acne Therapies. (Drugs, Pregnancy, and Lactation).

Topical and systemic agents are used in the treatment and prevention of acne, ranging from those that have negligible risks during pregnancy to a drug that is a major teratogen.

Azelaic acid (Azelex, Finevin), a topical antimicrobial, agent, is rated pregnancy risk factor B. It is embryotoxic in animals, but only at maternal toxic doses. No teratogenic effects have been observed in animals. About 4% of the dose is absorbed systemically in humans. This substance is found naturally in whole grain cereals and animal products, so levels of endogenous plasma levels of azelaic acid vary, ranging from about 20 ng/mL to 80 ng/mL, depending on dietary intake.

Benzoyl peroxide, which has multiple trade names, is rated risk factor C because it has not been studied in animals. It has antimicrobial and mild keratolytic effects. Even though there have been no studies in human pregnancy and lactation, it is considered safe because the amount absorbed through the skin is so small.

There are five other topical agents: clindamycin, erythromycin, thiouslfate, sulfacetamide, and tetracyclines. These agents do not present a significant risk during pregnancy when used topically.

The antiseptics, keratolytics, protectants, and adsorhents are common ingredients in antiacne cleansers and topical acne preparations. The antiseptics ethanol, isopropyl alcohol, phenol, sulfur, and acetone pose no risk during pregnancy when used topically, because absorption is low. Similarly, the keratolytic agents salicylic acid, resorcinol, and sulfur are not well absorbed and are safe during pregnancy and lactation. Protectives and adsorbents like zinc oxide also pose no risk. The same applies to hydrocortisone, which is added to products for its antiinflammatory effect.

Acne treatments in the retinoid class are considered potent human teratogens, although a topical retinoidlike compound known as adapalene (Differin) is rated C. Plasma concentrations of adapalene are less than 0.25 ng/mL after chronic use. There are no teratogenic effects of oral or topical adapalene in pregnant rats or rabbits. There is one human report of an infant whose mother used adapalene during pregnancy; that child had a birth defect that was not typical of retinoid-induced malformations.

The topical retinoid tazarotene (Tazorac, Avage), rated category X, is contraindicated in women who are or may become pregnant. Typical treatment produces ...