Betamethasone Dipropionate

Betamethasone dipropionate cream, 0.5% (augmented) can produce reversible hypothalamic-pituitary-adrenal (HPA) axis suppression with the potential for glucocorticosteroid insufficiency. This may occur during treatment or after withdrawal of treatment. Factors that predispose to HPA axis suppression include the use of high-potency steroids, large treatment surface areas, prolonged use, use of occlusive dressings, altered skin barrier, liver failure, and young age. Evaluation for HPA axis suppression may be done by using the adrenocorticotropic hormone (ACTH) stimulation test.

Betamethasone dipropionate cream, 0.5% (augmented) was applied once daily at 7 grams per day for 1 week to diseased skin, in adult subjects with psoriasis or atopic dermatitis, to study its effects on the HPA axis. The results suggested that the drug lowered adrenal corticosteroid secretion, although plasma cortisol levels did not go below the lower limit of the normal range.

In an open-label pediatric trial of 60 evaluable subjects (3 months to 12 years of age), 19 subjects showed evidence of HPA axis suppression. Four (4) subjects were tested 2 weeks after discontinuation of betamethasone dipropionate cream, 0.5% (augmented) and 3 of the 4 (75%) had complete rehcovery of HPA axis function. The proportion of subjects with adrenal suppression in this trial was progressively greater, the younger the age group.

If HPA axis suppression is documented, gradually withdraw the drug, reduce the frequency of application, or substitute with a less potent corticosteroid. Infrequently, signs and symptoms of steroid withdrawal may occur, requiring supplemental systemic corticosteroids.

Cushing’s syndrome and hyperglycemia may also occur with topical corticosteroids. These events are rare and generally occur after prolonged exposure to excessively large doses, especially of high-potency topical corticosteroids.

Pediatric patients may be more susceptible to systemic toxicity due to their larger skin surface to body mass ratios [see Use in Specific Populations (8.4)] .

Allergic contact dermatitis with corticosteroids is usually diagnosed by observing failure to heal rather than noting a clinical exacerbation. Such an observation should be corroborated with appropriate diagnostic patch testing. If irritation develops, topical corticosteroids should be discontinued and appropriate therapy instituted.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

In controlled clinical trials, involving 242 adult subjects, the adverse reaction associated with the use of betamethasone dipropionate cream, 0.5% (augmented)reported at a frequency of 0.4% was stinging. It occurred in 1 subject.

In a controlled clinical trial involving 67 pediatric subjects from 3 months to 12 years of age, the adverse reactions associated with the use of betamethasone dipropionate cream, 0.5% (augmented)occurred in 7 of 67 (10%) subjects. Reported reactions included signs of skin atrophy (telangiectasia, bruising, shininess).

Because adverse reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Postmarketing reports for local adverse reactions to topical corticosteroids may also include: burning, itching, irritation, dryness, folliculitis, acneiform eruptions, hypopigmentation, perioral dermatitis, allergic contact dermatitis, secondary infection, hypertrichosis, skin atrophy, striae, and miliaria.

Hypersensitivity reactions, consisting of predominantly skin signs and symptoms, e.g., contact dermatitis, pruritus, bullous dermatitis, and erythematous rash have been reported.

Teratogenic Effects: Pregnancy Category C

There are no adequate and well-controlled studies in pregnant women. Betamethasone dipropionate cream, 0.5% (augmented)should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Betamethasone dipropionate has been shown to be teratogenic in rabbits when given by the intramuscular route at doses of 0.05 mg/kg. The abnormalities observed included umbilical hernias, cephalocele, and cleft palate.

Systemically administered corticosteroids appear in human milk and can suppress growth, interfere with endogenous corticosteroid production, or cause other untoward effects. It is not known whether topical administration of corticosteroids can result in sufficient systemic absorption to produce detectable quantities in human milk. Because many drugs are excreted in human milk, caution should be exercised when betamethasone dipropionate cream, 0.5% (augmented)is administered to a nursing woman.

Use of betamethasone dipropionate cream, 0.5% (augmented)in pediatric patients younger than 13 years of age is not recommended due to the potential for HPA axis suppression [see Warnings and Precautions (5.1)] .

In an open-label HPA axis safety trial in subjects 3 months to 12 years of age with atopic dermatitis, betamethasone dipropionate cream, 0.5% (augmented) was applied twice daily for 2 to 3 weeks over a mean body surface area of 58% (range 35% to 95%). In 19 of 60 (32%) evaluable subjects, adrenal suppression was indicated by either a ≤5 mcg/dL pre-stimulation cortisol, or a cosyntropin post-stimulation cortisol ≤18 mcg/dL and/or an increase of <7 mcg/dL from the baseline cortisol. Out of the 19 subjects with HPA axis suppression, 4 subjects were tested 2 weeks after discontinuation of betamethasone dipropionate cream, 0.5% (augmented) and 3 of the 4 (75%) had complete recovery of HPA axis function. The proportion of subjects with adrenal suppression in this trial was progressively greater, the younger the age group [see Warnings and Precautions (5.1)] .

Because of a higher ratio of skin surface area to body mass, pediatric patients are at a greater risk than adults of systemic toxicity when treated with topical drugs. They are, therefore, also at greater risk of HPA axis suppression and adrenal insufficiency upon the use of topical corticosteroids.

Rare systemic effects such as Cushing's syndrome, linear growth retardation, delayed weight gain, and intracranial hypertension have been reported in pediatric patients, especially those with prolonged exposure to large doses of high potency topical corticosteroids.

Local adverse reactions including skin atrophy have also been reported with use of topical corticosteroids in pediatric patients.

Avoid use of betamethasone dipropionate cream, 0.5% (augmented)in the treatment of diaper dermatitis.

Clinical trials of betamethasone dipropionate, 0.5% (augmented)included 104 subjects who were 65 years of age and over and 8 subjects who were 75 years of age and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients. However, greater sensitivity of some older individuals cannot be ruled out.

Corticosteroids play a role in cellular signaling, immune function, inflammation, and protein regulation; however, the precise mechanism of action of betamethasone dipropionate cream, 0.5% (augmented)in corticosteroid responsive dermatoses is unknown.

Vasoconstrictor Assay

Trials performed with betamethasone dipropionate cream, 0.5% (augmented) indicate that it is in the high range of potency as demonstrated in vasoconstrictor trials in healthy subjects when compared with other topical corticosteroids. However, similar blanching scores do not necessarily imply therapeutic equivalence.

No pharmacokinetics trials have been conducted with betamethasone dipropionate cream, 0.5% (augmented). The extent of percutaneous absorption of topical corticosteroids is determined by many factors including the vehicle, the integrity of the epidermal barrier, and the use of occlusive dressings [see Dosage and Administration (2)] .

Topical corticosteroids can be absorbed through normal intact skin. Inflammation and/or other disease processes in the skin may increase percutaneous absorption. Occlusive dressings substantially increase the percutaneous absorption of topical corticosteroids [see Dosage and Administration (2)] .

Once absorbed through the skin, topical corticosteroids enter pharmacokinetic pathways similar to systemically administered corticosteroids. Corticosteroids are bound to plasma proteins in varying degrees, are metabolized primarily in the liver, and excreted by the kidneys. Some of the topical corticosteroids and their metabolites are also excreted into the bile.

Long-term animal studies have not been performed to evaluate the carcinogenic potential of betamethasone dipropionate.

Betamethasone was negative in the bacterial mutagenicity assay (Salmonella typhimurium and Escherichia coli), and in the mammalian cell mutagenicity assay (CHO/HGPRT). It was positive in the in vitro human lymphocyte chromosome aberration assay, and equivocal in the in vivo mouse bone marrow micronucleus assay.

Studies in rabbits, mice, and rats using intramuscular doses up to 1, 33, and 2 mg/kg, respectively, resulted in dose-related increases in fetal resorptions in rabbits and mice.