General
Certain cutaneous signs and symptoms of treatment such as erythema, scaling,
dryness, and stinging/burning may be experienced with use of DIFFERIN Gel, 0.3%.
These are most likely to occur during the first four weeks of treatment, are
mostly mild to moderate in intensity, and usually lessen with continued use
of the medication. Depending upon the severity of these side effects, patients
should be instructed to either use a moisturizer, reduce the frequency of application
of DIFFERIN Gel, 0.3% or discontinue use.
If a reaction suggesting sensitivity or chemical irritation occurs, use of
the medication should be discontinued. Exposure to sunlight, including sunlamps,
should be minimized during use of adapalene. Patients who normally experience
high levels of sun exposure, and those with inherent sensitivity to sun, should
be warned to exercise caution. Use of sunscreen products and protective clothing
over treated areas is recommended when exposure cannot be avoided. Weather extremes,
such as wind or cold, also may be irritating to patients under treatment with
adapalene.
Avoid contact with the eyes, lips, angles of the nose, and mucous membranes.
The product should not be applied to cuts, abrasions, eczematous or sunburned
skin. As with other retinoids, use of "waxing" as a depilatory method
should be avoided on skin treated with adapalene.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenicity studies with adapalene have been conducted in mice at topical
doses of 0.4, 1.3, and 4.0 mg/kg/day, and in rats at oral doses of 0.15, 0.5,
and 1.5 mg/kg/day. These doses are up to 3 times (mice) and 2 times (rats) in
terms of mg/m2/day the potential exposure at the maximum recommended
human dose (MRHD), assumed to be 2.5 grams DIFFERIN Gel, 0.3%. In the oral study,
increased incidence of benign and malignant pheochromocytomas in the adrenal
medullas of male rats was observed.
No photocarcinogenicity studies were conducted. Animal studies have shown an
increased risk of skin neoplasms with the use of pharmacologically similar drugs
(e.g., retinoids) when exposed to UV irradiation in the laboratory or to sunlight.
Although the significance of these studies to human use is not clear, patients
should be advised to avoid or minimize exposure to either sunlight or artificial
UV irradiation sources.
Adapalene did not exhibit mutagenic or genotoxic effects in vitro (Ames
test, Chinese hamster ovary cell assay, mouse lymphoma TK assay) and in vivo
(mouse micronucleus test).
Reproductive function and fertility studies were conducted in rats administered
oral doses of adapalene in amounts up to 20 mg/kg/day (up to 26 times the MRHD
based on mg/m2 comparisons). No effects of adapalene were found on
the reproductive performance or fertility of the F0 males or females.
There were also no detectable effects on the growth, development and subsequent
reproductive function of the F1 offspring.
Pregnancy
Teratogenic effects. Pregnancy Category C.
Retinoids may cause fetal harm, when administered to pregnant women. Adapalene has been shown to be teratogenic in rats and rabbits when administered orally (see Animal Data below). There are no adequate and well-controlled studies in pregnant women. DIFFERIN Gel, 0.3% should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. The safety and efficacy of DIFFERIN Gel, 0.3% in pregnancy has not been established.
Human Data
In clinical trials involving DIFFERIN Gel, 0.3% in the treatment of acne vulgaris, women of child-bearing potential initiated treatment only after having had a negative pregnancy test and used effective birth control measures during therapy. However, 6 women treated with DIFFERIN Gel, 0.3% became pregnant. One patient elected to terminate the pregnancy, two patients delivered healthy babies by normal delivery, two patients delivered prematurely and the babies remained in intensive care until reaching a healthy state and one patient was lost to follow-up.
2. Animal Data
- No teratogenic effects were seen in rats at oral doses of 0.15 to 5.0 mg/kg/day
adapalene representing up to 6 times the maximum recommended human dose (MRHD)
based on mg/m2 comparisons. Adapalene has been shown to be teratogenic
in rats and rabbits when administered orally at doses ≥ 25 mg/kg representing
32 and 65 times, respectively, the MRHD based on mg/m2 comparisons.
Findings included cleft palate, microphthalmia, encephalocele and skeletal
abnormalities in the rat and umbilical hernia, exophthalmos and kidney and
skeletal abnormalities in the rabbit.
- Cutaneous teratology studies in rats and rabbits at doses of 0.6, 2.0, and
6.0 mg/kg/day exhibited no fetotoxicity and only minimal increases in supernumerary
ribs in both species and delayed ossification in rabbits. Systemic exposure
(AUC0-24h) to adapalene 0.3% gel at topical doses of 6.0 mg/kg/day
in rats and rabbits represented 5.7 and 28.7 times, respectively, the exposure
in acne patients treated with adapalene 0.3% gel applied to the face, chest
and back (2 grams applied to 1000 cm2 of acne involved skin).
Nursing Mothers
It is not known whether this drug is excreted in human milk. Because many drugs
are excreted in human milk, caution should be exercised when DIFFERIN Gel, 0.3%
is administered to a nursing woman.
Pediatric Use
Safety and effectiveness in pediatric patients below the age of 12 have not
been established.
Geriatric Use
Clinical studies of DIFFERIN Gel, 0.3% did not include subjects 65 years of
age and older to determine whether they respond differently than younger subjects.
Safety and effectiveness in geriatric patients age 65 and above have not been
established.
Last updated on RxList: 7/17/2007