Avage (Tazarotene) - Drug Interactions, Contraindications, Overdosage, etc

DRUG INTERACTIONS

Drug Interactions

Concomitant dermatologic medications and cosmetics that have a strong drying effect should be avoided. It is also advisable to "rest" a patient's skin until the effects of such preparations subside before use of AVAGE^® Cream is begun.

OVERDOSAGE

Excessive topical use of AVAGE^® Cream 0.1% may lead to marked redness, peeling, or discomfort (see PRECAUTIONS: General).

AVAGE^® Cream 0.1% is not for oral use. Oral ingestion of the drug may lead to the same adverse effects as those associated with excessive oral intake of Vitamin A (hypervitaminosis A) or other retinoids. If oral ingestion occurs, the patient should be monitored and appropriate supportive measures should be administered as necessary.

CONTRAINDICATIONS

Retinoids may cause fetal harm when administered to a pregnant woman.

In rats, tazarotene 0.05% gel administered topically during gestation days 6 through 17 at 0.25 mg/kg/day resulted in reduced fetal body weights and reduced skeletal ossification. Rabbits dosed topically with 0.25 mg/kg/day tazarotene gel during gestation days 6 through 18 were noted with single incidences of known retinoid malformations, including spina bifida, hydrocephaly, and heart anomalies.

Systemic exposure (AUC_0-24hr) to tazarotenic acid at topical doses of 0.25 mg/kg/day tazarotene in a gel formulation in rats and rabbits represented 2.4 and 26 times, respectively, the maximum AUC_0-24hr in patients treated with 2 mg/cm² of tazarotene cream 0.1% over 15% body surface area for fine wrinkling and mottled hyperpigmentation.

As with other retinoids, when tazarotene was given orally to experimental animals, developmental delays were seen in rats, and teratogenic effects and post-implantation loss were observed in rats and rabbits at doses producing 2.1 and 52 times, respectively, the maximum AUC_0-24hr in patients treated with 2 mg/cm² of tazarotene cream 0.1% over 15% body surface area for fine wrinkling and mottled hyperpigmentation.

In a study of the effect of oral tazarotene on fertility and early embryonic development in rats, decreased number of implantation sites, decreased litter size, decreased number of live fetuses, and decreased fetal body weights, all classic developmental effects of retinoids, were observed when female rats were administered 2 mg/kg/day from 15 days before mating through gestation day 7. A low incidence of retinoid-related malformations at that dose were reported to be related to treatment. That dose produced an AUC_0-24hr that was 6.7 times the maximum AUC_0-24hr in patients treated with 2 mg/cm² of tazarotene cream 0.1% over 15% body surface area for signs of fine wrinkling and mottled hyperpigmentation.

Systemic exposure to tazarotenic acid is dependent upon the extent of the body surface area treated. IN PATIENTS TREATED TOPICALLY OVER SUFFICIENT BODY SURFACE AREA, EXPOSURE COULD BE IN THE SAME ORDER OF MAGNITUDE AS IN THESE ORALLY TREATED ANIMALS. As a retinoid, tazarotene is a teratogenic substance, and it is not known what level of exposure is required for teratogenicity in humans. However, there may be less systemic exposure in the treatment of the face alone, due to less surface area for application (see CLINICAL PHARMACOLOGY: Pharmacokinetics).

There were thirteen reported pregnancies in patients who participated in the clinical trials for topical tazarotene. Nine of the patients were found to have been treated with topical tazarotene, and the other four had been treated with vehicle. One of the patients who was treated with tazarotene cream elected to terminate the pregnancy for non-medical reasons unrelated to treatment. The other eight pregnant women who were inadvertently exposed to topical tazarotene during the clinical trials subsequently delivered apparently healthy babies. As the exact timing and extent of exposure in relation to the gestation times are not certain, the significance of these findings is unknown.

AVAGE^® Cream is contraindicated in women who are or may become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, treatment should be discontinued and the patient apprised of the potential hazard to the fetus. Women of child-bearing potential should be warned of the potential risk and use adequate birth-control measures when AVAGE^® Cream is used. The possibility that a woman of child-bearing potential is pregnant at the time of institution of therapy should be considered. A negative result for pregnancy test having a sensitivity down to at least 50 milli International Units per mL for human chorionic gonadotropin (hCG) should be obtained within 2 weeks prior to AVAGE^® Cream therapy, which should begin during a normal menstrual period (See also PRECAUTIONS: Pregnancy: Teratogenic Effects).

AVAGE^® Cream is contraindicated in individuals who have shown hypersensitivity to any of its components.